2016 JAF Grand Touring Car 300(JAF

Transcription

2016 JAF Grand Touring Car 300（JAF-GT300） Technical Regulations
2016 JAF Grand Touring Car 300(JAF-GT300) Technical Regulations
Definition:
Automobile having two seats at least and one or more doors on each side respectively for getting on and
off which is categorized as follows:
1. Grand Touring Car 300 stipulated in the section 1 of this chaper (JAF-GT300)
2. Grand Touring Car 300 Mother Chassis stipulated in the section 2 of this chaper (JAF-GT300MC)
Section 1: Grand Touring Car 300(JAF-GT300)
Article 1: Vehicle
1.1) Eligibility as an original vehicle
Cars produced by an automobile manufacturer, comply with legal requirements for road use and
satisfy either of the following conditions:
(1) homologated in FIA Group N/A/GT3/GT2/GT1, JAF Production Touring Cars or Special Touring
Cars,
(2) registered with JAF as registered vehicles.
1.2) Original engine
An engine which is produced by its original manufacturer and is legal for road use, and admitted by
FIA and/or JAF.
1.3) Optional parts
The use of the optional parts which are mentioned in the FIA and/or JAF homologation form or the
JAF-GT main specifications register form of the cars registered with JAF is authorized.
Article 2: Regulations
2.1) Modifications
Any modifications which are not permitted in this Section are prohibited.
General prescriptions and Safety Equipment
Cars must comply with the following requirements of Appendix J. Art.252 "General prescription" and
Art.253 "Safety Equipment", which are not already covered in these regulations.
- 252.1) General remarks
＊ except for Art.252.1.2
- 252.2) Dimension and Weight
- 252.3) Engine
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- 252.4) Transmission
- 252.5) Suspension
- 252.6) Wheels
- 252.7) Bodywork / Chassis / Bodyshell
＊ Replace Art.252.7.3 "Cockpit" by the following text.
・Cockpit
The cockpit is that volume of the vehicle separated from the rest of the vehicle by fixed front
and rear bulkheads.
For 2-volume vehicles, the cockpit is that volume between the front bulkhead and the bulkhead
behind the rear edge of the rear-most seat. Remaining inner space behind that is referred to as
the luggage compartment.
The bulkheads must be constructed of highly flameproof rigid materials.
The cockpit must be completely insulated by the bulkheads from the engine compartment, fuel
tank, oil tank, gearbox, propeller shaft, and all joints of piping and tubing (connecting these
areas). Any and all devices/substance that is potentially dangerous to the vehicle driver must be
installed outside of the cockpit (on the other side of the bulkhead).
Only the following accessories may be installed in the cockpit.
* Spare wheels
* Tools
* Spare parts
* Safety equipment
* Communication equipment
* Ballast (if permitted)
* Windscreen washer water container
* Equipment for cooling suit
On 2-volume vehicles, the oil tank may be installed to the luggage compartment provided that
bulkheads are used to protect against oil leakage and sparking.
- 252.8) Electrical system
- 252.9) Fuel - Combustive
＊ Refueling tank must comply with drawing 252-7 with fuel hose of maximum 5m in length, but
flow restrictor is not mandatory.
- 252.10) Brakes
- 253.1) Dangerous car
- 253.2) Optional device
- 253.3) Lines and Pumps
- 253.4) Safety of braking and Steering systems
- 253.5) Additional fasteners
- 253.6) Safety belts
- 253.7) Extinguishers - Extinguishing systems
- 253.8) Safety cages
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- 253.9) Rear view
- 253.10) Towing eye
- 253.11) Windows / Nets
＊ Except for the following text
"The windows must be certified for road use, their marking standing as proof."
＊ Add the following text.
Anti-dazzling treatment may be applied as a strip along the upper edge of the glazed surface.
The width of the strip must not exceed 100 mm.
- 253.12) Safety fixing device for Windscreen
- 253.13) General circuit breaker
＊ Replace text "As for the outside, the triggering system of the circuit breaker will compulsorily
be situated at the lower part of the windscreen mounting of the driver’s side for closed cars" by
"As for the outside, the triggering system of the circuit breaker will compulsorily be situated at
the lower part of the windscreen mounting of the opposite side of driver’s side for closed cars"
In vehicles whose design makes it impossible to install the circuit breaker close to the lower part
of front windscreen mounting bracket, the circuit breaker may be installed outside either of the
passenger side center pillar or the quarter pillar, which permits operation from outside.
- 253.14) FIA approved safety fuel tanks
- 253.15) Protection against fire
- 253.16) Seats, attachments and supports
- 253.17) Pressure control valves
However, if the prescriptions which have the same meaning as those of the above Articles are defined
in this Section, prescriptions in this Section should be obeyed.
2.1.1) Material restrictions
2.1.1.1) Composite material (Including carbon and aramid fiber)
If only the use of the material is authorized in this Section or the use of the material is standardized
on the specific parts or areas of the original vehicle and engine, these composite materials can be used
in the relevant parts or areas.
2.1.1.2) Titanium and ceramics
Regardless of the provisions of the present regulations, the following must be respected.
1) If the use of these materials is standardized on the specific parts or areas of the original vehicle and
engine, these materials can be used only in the relevant parts or areas.
2) The use of these materials is permitted for the following parts:
(1) connecting rods
(2) intake and exhaust valves
(3) valve retainers
(4) heat shield
(5) apex seals (rotary engine)
(6) brake caliper pistons
(7) supercharger
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2.1.1.3) Aluminum alloy
The use of aluminum alloy which has a modulus of elasticity greater than 80Gpa is forbidden except
for brake calipers.
2.1.1.4) The other materials
The use of a material with a specific gravity greater than 12.0 is forbidden.
2.1.2) Control function restrictions
1) Any automatic or electronic chassis control system or function, excluding anti-lock brake system
and traction control system which are submitted to and approved by the JAF, is forbidden, even if
the original vehicle has it. This includes the systems listed in the Appendix 1 of this Section.
A simple open-loop electrical switch activated by the driver acting on a system is not considered
to be electronically controlled.
2) It is permitted to use (add) a speed limiter in order to comply with the speed limit in the pit lane.
2.2) Compliance with the rules and regulations
It is the duty of each competitor to give an explanation and accept any checks at the request of the
scrutineers and the Steward of the Meeting of the event concerned in order to satisfy them that his car
complies with the rules and regulations in their entirety at any time during an event.
2.2.1) Measurements
During the event, all required measurements will be made at the location specified by the chief
scrutineer and with measuring instrument and apparatus which will be provided by the event organizer.
No protest can be accepted against these measurement site, measuring instruments and/or equipment,
and measurement methods.
Article 3: Bodywork and exterior dimensions
Save the modifications authorized in this Section, dimensional specifications of the original vehicle
mentioned in the homologation form and documents in relation to the registered cars and also their outer
shapes without bolts for fitting must be maintained.
3.1) Dimensions
3.1.1) Overall length
The overall length of the car must not exceed the sum total of the dimensions of the overhang and the
wheel base permitted under Art.3.1.3) below.
3.1.2) Maximum height
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The dimension from the bottom surface of the flat bottom to the top of the roof (roof reference plane
without local projecting shape, roof rail and auxiliaries such as antenna) must not be less than 1,100mm
when measured perpendicular to the bottom surface of the flat bottom. In order to comply with this rule,
it is permitted to remove the side sill and the floor, and downward raise of the side sill and moving of
the position of the floor are also permitted.
3.1.3) Overhang and wheel base
1) Front overhang
The overhang may be extended up to 950mm. However it must not be extended more than 120mm
from the frontal edge of the front bumper of the original vehicle.
2) Wheelbase
When the dimension of the wheelbase is less than 2600mm, it may be extended by 5%. When the
dimension of the wheelbase is 2601mm or more, it may be extended by 1%. However its midpoint
may be changed within the range of +/-30mm longitudinally from the midpoint of the wheel base of
the original vehicle which is regarded as a base point (this must be notified to JAF with dimensions
from the position definable.)
3) Rear overhang
When the dimension of the rear overhang of the original vehicle is less than 950mm, it may be
extended up to 950mm.
3.2) Windows
3.2.1) Front window
The front windshield must be in accordance with the rules under Article 9 of Chapter 4 Safety
regulations for homologated cars and registered vehicles. However it is permitted;
1) that a colorless transparent film is attached to the surface of the front windshield in order to protect
it.
2) that the material of the front windshield is changed into polycarbonate of which thickness is no less
than 6mm instead.
3.2.2) The other windows
1) The window glass may be replaced with some other transparent material which must permit the
cockpit interior to be visible, provided the same installation position, thickness, and shape as the
original glass are maintained.
2) Operational method and regulating system of the door window glass may be changed providing that
the original function of the door window glass is maintained. To the door of driver's side, door
window glass may not be fitted, however, it is obligatory to install protective nets defined under
Article 22 "Net" of the Chapter 4 Safety regulations for homologated cars and registered vehicles.
3) The window glass may have openings, however the total area of the openings must not exceed 15%
of the area of the each window concerned. There is no restriction on the shape of the ventilation
openings.
4) Air scoops may be installed to the outside surface of any window glass. Maximum protrusion of the
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air scoop shall be 50mm measured perpendicularly from the outer window surface.
5) Following the removal of auxiliary accessories such as weather stripping and molding, it is
permissible to install the window glass (except door window glass) directly to the vehicle bodywork.
6) The surface of the windows that are installed at the rear of the door windows on the lateral surface
of the car may protrude to the plane of extended surface of the door window glass.
7) A partition window may be replaced with a firewall.
8) When a tinted glass or a window film is used for side or rear windows, a driver inside the car must
be visible at a distance of 5 meters.
9) Windows situated to the rear of the door (of the front door for 4-door vehicle) and to the rear of the
rear bulkhead may be devitrified. If it is devitrified by painting, it must be clearly distinguished by
the contrastive color with the livery.
3.3）Bodywork
3.3.1) Changes in bodywork materials
Materials of front and rear bumper, fender, bonnet (including engine-cover), rear hatch gate and bootlid components may be replaced by plastic materials or light metals provided that these substitutions
maintain enough structural strength and do not result in configurative changes. However, if the bonnet
(including engine-cover) and the rear hatch gate include glass component and the glass material is
changed, former part of glass component must be clearly distinguished by a parting line. If the part is
painted, it must be clearly distinguished by the contrastive color with the livery.
Nevertheless configurative changes may be made only if the prescriptions of this Section so defined.
It is permitted to remove the reinforcement members on the back of the structures of bonnet (including
engine-cover), rear hatch gate and boot-lid provided the structural strength of these structures are
maintained.
3.3.2) Door
1) For the door configuration, it is permitted that its area between the bottom surface of the flat bottom
and up to 120mm above it is removed, but the shape of the other part must be original. The back of
the door configuration may be altered.
2) The materials of the door can be changed into plastic materials or light metals provided that this
maintains sufficient strength of the structure.
3) Door hinge can be changed only for the purpose of giving the driver a quick escape from the car
during accident. If a door hinge is included in the part removed under 1) above, the relevant door
hinge may be changed.
For 4-door vehicle, four or more fasteners comply with 3.3.4) may be used instead of door hinges
and door locks when the function of opening/closing for rear doors is retained.
4) If the door mirrors are moved, original door mirror bases can be changed into plastic materials or
light metals.
5) For 4-door vehicle, rear doors may be widened in their width. The width shall be limited to the
extended outer surface of the rear fender. However the configuration of the car when viewed from
the side must be retained other than the part which is cut for forming wheel arch.
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The function of opening/closing for rear doors is free.
3.3.3) Openings made in the bodywork
3.3.3.1) Openings in the bonnet (including engine-cover), rear hatch gate and boot-lid
1) They may be made to allow dissipation of heat and cooling provided the configurations of these
covers are not modified substantially. The openings are also allowed to be closed providing the
closed areas keep the original shapes or form outer enveloping surfaces.
However the opening of the bonnet (including engine-cover) must fulfill the following conditions:
(1) It is situated 100mm forward of the rear edge of the bonnet (including engine-cover).
(2) The longitudinal length of the opening is 1,000mm maximum from the rear edge of the bonnet
(including engine-cover).
(3) The maximum width is up to 625mm to the right and left respectively from the longitudinal car
centerline.
the rear edge of
the bonnet
Parallel lines of the rear
edge of the bonnet
Drawing 7-1
2) They may be made in the rear hatch gate and boot-lid to allow dissipation of heat and cooling
provided the configurations of these are not modified substantially.
3) Opening accompanied by a change in hatch gate configuration may be made. However if it is made
within the extent of the original window, the change is limited within 15% of the original window
surface of the rear hatch gate and the total width of the opening is 400mm which must be symmetrical
to the longitudinal center line of the car.
4) Louvers, ribbing or lips etc. of which maximum protrusion up to 20mm may be installed and ducts
which are connected to the openings may be added. However when viewed from above these
openings must not permit the inside structure to be visible other than that of the duct connected to
an opening concerned.
3.3.3.2) Opening on fender
Cut-out (exit hole) may be created on the fender situated rear of the rearmost part of the complete
wheel to permit the escape of air used to cool the brakes. The inside must not be visible through this
exit hole when viewed from above and the side.
However, when an exit hole used to provide an exit for air already used to cool the brakes is situated
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behind the rear wheels, except the part below the horizontal plane passing through the center of the rear
complete wheel, it must be covered either with a louver or with a very fine wire mesh in order to allow
nothing to exit other than air.
When opening is made on the fender for passing an exhaust pipe, the opening may have a gap up to
half of the diameter of the exhaust pipe.
3.3.3.3) Opening on ceiling
One opening may be made on the ceiling providing the following conditions are respected:
1) It must be positioned no less 100mm behind of the rear edge of the front windshield. However if it
is made for introducing intake air to the rear engine, it must be situated behind the rearmost edge of
the rear bulkhead (air duct can be connected to the opening made on the ceiling).
Only if an intake duct is installed on the roof for engine as a standard equipment of the original
vehicle, it is permitted to take air for the engine from above the roof. However the shape of the
duct may not be altered from that of the original vehicle. Nonetheless for the competition car
manufactured before 2015, it is permitted to take air for the engine from above the roof even if an
intake duct is not installed on the roof for engine as a standard equipment of the original vehicle.
2) Longitudinal length of the opening must not exceed the quarter of the ceiling's total length.
3) Its maximum width must be 400mm and symmetrical to the longitudinal centerline of the car.
4) It must not protrude from the surface of the car except air scoops which may be installed to the
outside surface of the bodywork, of which maximum protrusion shall be 40mm measured
perpendicularly from the outer surface.
5) When viewed from above, it must not permit the interior to be visible.
6) The structure inside the cockpit shall be no more than 150mm underneath the inside surface of the
ceiling and also be 100mm minimum above the driver's head.
3.3.3.4) Openings on the side of the bodywork
Openings can be made for the rear doors in case of 4-door vehicle, and on the body side panel at the
rear part of the door in case of 2-door vehicle, for the purpose of for example leading air for cooling of
heat exchanger providing the following conditions are respected:
1) (1) In case of 4-door:
It should be situated inside the peripheral parting line of the rear door and under the parallel plane
passing 770mm above the bottom plane of the flat bottom (The shaded portion of the Drawing 7-2).
(2) In case of 2-door:
It should be situated under the parallel plane passing 770mm above the bottom plane of the flat
bottom and in the area determined by the backward extended lines from the rear edge of the door
parting line and the lower parting line of the door and a plane perpendicular to the bottom plane of
the flat bottom passing the center of the rear wheel axle (The shaded portion of the Drawing 7-3).
2) It must not allow the inner part to be seen from the side and above.
3) Louver-shaped is prohibited and air scoop of maximum 50mm protrusion may be installed for the
opening. However the maximum width of the competition vehicle must not be exceeded as a result.
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770mm
Drawing 7-2
770mm
Flat bottom
Flat bottom
The backward extended lines from
the rear edge of the lower parting
line of the door
Drawing 7-3
3.3.3.5) Openings for the rear part of the bodywork
Openings situated at the rear of the bodywork must be covered with a very fine wire mesh or a
punching metal etc. .
3.3.4) Hinges of bonnet (including engine-cover), rear hatch gate and boot-lid
Hinges may be removed provided that the fasteners do not allow bonnet, rear hatch gate and bootlid to open during the vehicle in motion.
Where the engine or the fuel tanks are installed, these fasteners must be able to remove without tools.
The fasteners must be clearly indicated by a red (or contrastive color) arrow.
3.3.5) Bodywork (monocoque structure) and bulkhead
The original bodywork (monocoque structure) and bulkhead must be maintained for the cockpit area
other than the modifications specifically allowed in this Section.
The shape and material of "the back end panel" are free provided the external appearance of the car
is not modified, however bodywork structure that is not covered with fender, bumper and finisher must
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be remained.
Other than the front and rear bulkheads, openings situated originally in the cockpit may be sealed.
3.3.5.1) Front bulkhead (including cowl top)
1) Original front bulkhead may be removed for installation of a new bulkhead which isolates the cockpit
entirely.
However, if the cowl top is also removed the supporting structure for the lower edge of the front
window must be newly constructed.
The material and the shape of the cowl top cover are free. But it must not protrude from the perimeter
of the rear edge of the bonnet when viewed from the front.
2) Opening which is connected to the opening defined under Art.3.3.3.1) is permitted for the purpose
of ventilation of the cockpit provided the isolation function is maintained.
If the vent of the cockpit is connected to the duct installed at the back of the bonnet (including enginecover), the connected part must be of the structure which can prevent fire from intruding into the
cockpit when a fire in the engine compartment.
3) The area to which the front bulkhead reference plane (plane on the front side of the car) may be
installed:
The longitudinal position of the new bulkhead should be +/-250mm from the original position of the
original vehicle.
4) The shape and material of the front bulkhead, structure of connection of the openings defined under
Art.3.3.3.1) or a part which seals the openings existed originally:
Shape:
free
Material: identical to that of the monocoque of the original vehicle and has equal or greater thickness
than that.
5) Openings may be made for the purpose of modifications permitted under Art.3.3.8)" Tunnel
installation to the floor part", 3.3.12.1) and by this provision, and for connecting the tubular structure
defined under Art.3.3.6) "Bodywork structure fore of the front bulkhead and hind of the rear
bulkhead "to the rollcage. However if it is necessary to create an opening its size must be minimal
for its purpose.
3.3.5.2) Rear bulkhead
1) New bulkhead may be installed after the rear bulkhead of the original vehicle is removed.
2) It is obligatory to install rear bulkhead which is positioned behind the driver’s seat when viewed
through from the side and can isolate the cockpit completely. However, minimum opening connected
to the opening according to 3.3.3.1)-3) for the ventilation of the cockpit is permissible on condition
that the cockpit’s isolation function is duly maintained.
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Area permitted for bulkhead installation
Drawing 7-4
3) The shape and material of the rear bulkhead, structure of the connection of the openings according
to 3.3.3.1-3) or a part which seals opening existed originally.
Shape: Free
Material: The bulkhead or the part must be made of a rigid and sufficiently fireproofing material.
(1) Material which is identical to that of the monocoque of the original vehicle and has equal or
greater thickness than that.
(2) Carbon fiber material having honeycomb construction no less than 10mm thickness.
(3) Carbon fiber composite having no less than 3.5mm thickness.
4) A structure can be built, for which a plane extended horizontally from the main bottom plane of the
floor can be connected with a plane extended from the main plane of the rear bulkhead.
3.3.5.3) Rear midship-engine vehicles
The followings are adopted for rear midship-engine vehicles in addition to the above 3.3.5.1)"Front
bulkhead" and 3.3.5.2)"Rear bulkhead":
1) The bulkhead separating the engine compartment from the luggage compartment and the floor part
of the engine compartment and the luggage compartment may be removed, save the members which
affect the bodywork such as reinforcement members for the floor part of luggage compartment.
2) If the fuel tank is installed to the luggage compartment of rear midship-engine vehicles, there must
be no cut-out in the said bulkhead.
3) Structural members supporting the bulkheads which isolate the engine compartment from the luggage
compartment may be changed into a detachable construction provided that this construction does not
affect the strength of the bodywork.
3.3.6) Bodywork structure fore of the front bulkhead and hind of the rear bulkhead
Main structure (structural framework) situated fore of the front bulkhead and/or hind of the rear
bulkhead may be cut and replaced by the tubular structure which is connected with the rollcage.
The material of the outer plane behind the rear bulkhead which serves also as a part of body structure
(monocoque structure) may be replaced by synthetic resin or light metals provided that substantial
strength and the shape, excluding permitted conditions defined under 3.3.3.3) "opening on ceiling", are
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maintained . The plane may be removable only when it can be separated from each door, fender and
boot-lid. However, no play or gap between the part and the silhouette is permitted when seen from the
front, the rear and the side and it must be secured rigidly by hinges, a locking mechanism or the four or
more fasteners defined under Article 3.3.4).
When the main structure(structural framework) fore of the frond bulkhead is replaced by the tubular
structure connected with the rollcage, it is obligatory to install an impact absorbing structure ( a
crushable structure) defined under Article 12.7) "Frontal (back) protection structure" of the present
regulations.
A tubular structure must conform to the following conditions:
1) Material: steel
2) Yield strength: endurable with 5.5W longitudinal, 1.5W lateral and 1.5W vertical loads (W=1,500kg)
(1) Parts to which the above loads are applied:
Front tubular structure: attachment points of the crushable structure
Rear tubular structure: the rear edge of the tubular frame concerned
(2) Conditions when the above loads are applied:
(1) The floor part of cockpit (cabin) is fixed
(2) In running order (example; holes for the fixation of the suspensions are not closed. If an
engine, a gear box or a flat bottom etc. has a function as a stress member, it remains on that
part.)
(3) The following verification of withstanding against the obliged yield strength shall be
submitted to JAF:
(1) The result of the static load test, of the strength calculation (calculation report) or of the
analysis of the strength must be presented to JAF.
(2) Drawing of rollcage and tubular flame general construction and tube material &
dimensions.
It is not necessary to present the verification every year unless the vehicle type and its design
remain the same.
3) Method of fixation to rollcage, diameter and thickness of pipes
Free, including shape of the tubes.
However any processing or modification to the rollcage homologated by FIA or JAF following
the fixation of a tubular structure is not permissible.
4) Even if the engine is dismounted, the parts which suspend the bodywork must work normally.
3.3.7) Flat bottom and floor
It is obligatory to install a flat bottom which complies with the following conditions. The flat bottom
must be installed across the total width of the car seen from its underneath without tire wheel housing
and outer mirrors.
1) A solid body that is rigid, flat and impervious plane under any circumstance, which covers the lower
surface of the car between the center line of the rotational axle of the front wheel and the center line
of the rotational axle of the rear wheel must be rigidly secured.
Materials are free.
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Minimum width of the flat bottom is 950mm and it shall be symmetrical about the longitudinal
center line of the car.
This plane may be composed of several pieces. However the gap of each piece between them
must be less than 1mm and the tolerance in vertical direction across the whole plane area is 5mm
maximum.
2) In any case, the flat bottom must not have an aerodynamic effect.
3) No air stream may pass between the floor of cockpit and the flat bottom except the parts fore of the
bulkhead, of passing the exhaust pipes(except side sill), center tunnel and tunnel for rear engine
vehicles.
Bulkhead
Floor
Center line of the front wheel rotational axle
Flat bottom
Center line of the rear wheel rotational axle
Front edge of floor
Front edge of flat bottom
Rear edge of flat bottom
Drawing 7-5
4) Any suspended part of the car, regardless of the provisions under Art. 3.4.1) "Front aerodynamic
device" of the present regulations, must not situate below the plane formed by the flat bottom.
5) It is permitted to have radius of maximum 25mm upwardly at the periphery edge of the flat bottom.
6) Openings may be made into the flat bottom for the following reasons.
(1) Pneumatic jack use
(2) Extraction of heat from the exhaust pipe ;
- The holes should be within the area corresponding to exhaust pipe diameter.
- The holes must follow the shape of exhaust pipe.
- Maximum diameter is 50mm
- Number of the ventilation holes is free.
(3) Sensor use (Maximum diameter is 20mm)
However, for the purpose of passing the optical axis of the ride height sensor, it is permitted
to make maximum 4 holes (slits) of the dimensions of 20mm x 50mm (maximum).
7) The flat bottom can be installed in such a way that the straight part of lower surface of side sill except
flange is the top of it. However if the flat bottom interferes with the floor of the original vehicle, the
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original floor may be modified or new flat floor of the material prescribed in Article 3.3.9.1.-2)
"Shape and material" may be created.
8) In order to mount the flat bottom, part situated below the straight line of the lower surface of the side
sill may be bent or cut.
Fender arch
Fender arch
Side sill
Flat bottom
Straight line of the lower surface of the side sill
Section
Side sill
Side skirt
Floor
Flat bottom
Bend or cut
Drawing 7-6
9) Provisions under Art. 3.3.12.1)- (3) "The shape of the tire housing" shall be satisfied.
10) Skid blocks designated by JAF must be attached to the front and the rear respectively. The skid
block must have thickness of minimum 8mm at no less than one part on the perimeter.
3.3.8）Tunnel installation to the floor part
1) Center tunnel
A new tunnel may be created following removal of the center tunnel of the original vehicle within
the following dimensions.
Material: must be rigid and sufficiently fireproofing material.
Permitted volume with dimensions
for installation of center tunnel
Rear Bulkhead
Symmetrical to
the center line
of car
Front Bulkhead
800mm
Lower surface of the flat bottom
Drawing 7-7
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14/45
2) Tunnel installation for exhaust pipes
(1) One tunnel may be installed of which width up to 210mm and height up to 210mm provided it
does not affect the shape of the flat bottom toward the upper direction of the floor. However if a
car has an engine having banking on its RH and LH at the front, it is permitted to install one
tunnel for the RH and LH respectively.
(2) The processing to the surface of the bulkhead should be limited to a circumscribed square with a
diameter up to 210mm.
3.3.9) Body side panel and side sill
3.3.9.1) Body side panel, side sill and floor
1) Body side panel, side sill and floor situated below the parting line at the lower part of the door window
may be newly installed after original body side panel, side sill and floor are removed.
2) Shape and material:
Shape: free
However outer surfaces of the body side panel and the side sill must be situated no more than 250mm
above the bottom surface of the flat bottom and between 120mm transversely inward from the lower
edges of the door outer surfaces. But modifications permitted under Art.3.3.8)-2) "Tunnel installation
for exhaust pipes" is permissible.
Material: rigid and sufficiently fireproofing material composed of the followings:
3) The structure which allows air to pass inside the side sill is prohibited.
4) To the lower part of the door between the front fender and the rear fender, side sill cover may be
installed following widening of outer surface of the original vehicle (door outer panel, outer surface
of the side sill or outer surface of side sill cover), however parts not widened must maintain identical
surface with the original vehicle.
The structure which allows air to pass between the outermost surface of this part and side sill is
prohibited. When an opening is made for the purpose of passing exhaust pipe on the outmost surface,
it should be limited to a circumscribed square with a diameter up to 120mm when viewed from the
side.
5) If the side sill cover is installed, its material is free.
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Door
Outer surface of body side panel & side sill
Side sill cover
Body side panel
& side sill
Lower edge of the door outer surface
Side skirt
Flat bottom
Drawing 7-8
Exhaust pipe tunnel
Door
Body side panel
& side sill
Side sill cover
MAX
Door lower edge
Exhaust
pipe
Side skirt
Flat bottom
MAX
Drawing 7-9
3.3.10) Bumpers
3.3.10.1.1) Front bumper
1) The shape of upper part which is divided by a horizontal plane passing 300mm above the flat bottom
base must be retained as original between the base points P1 and P2 of the Drawing 7-10. P1 and P2
are the points where a straight line having 75% of the maximum width of the original vehicle which
intersect vertically with the longitudinal centerline of the car and symmetrical to it, contact with the
perimeter of the front bumper when viewed from above.
2) Between the base points P1 and P2 (Drawing7-10) defined above 1), the bumper part situated more
than 40mm and 300mm or less above the bottom surface of the flat bottom may be modified
(including addition of opening) if the area falls inside the contour of the original bumper.
3) There are no restrictions on reinforcement members for the inside of the bumper.
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3.3.10.1.2) Rear bumper
1) The shape of the upper part between the base points P3 and P4 on the Drawing 7-10 and aloft the
horizontal plane passing 300mm above the bottom surface of the flat bottom must be retained as
original. P3 and P4 are the points where a straight line having 80% of the maximum width of the
original vehicle which intersect vertically with the longitudinal centerline of the car and symmetrical
to it, contact with the perimeter of the rear bumper when viewed from above.
2) Modification(including cut) of bumper configuration situated lower than 300mm from the bottom
surface of the flat bottom may be permitted within the area determined by the rear axle center line
and the line parallel to it at the rear edge of the bodywork and the straight lines at an angle of 30°in
relation to the latter at the points laying 665mm from the longitudinal centerline of the car each side
and the lines parallel to the longitudinal centerline which contact with the outmost perimeter of the
bodywork (refer to Drawing 7-11). However horizontal surface must be maintained at the bottom of
the modified bumper within 650mm from the longitudinal centerline of the car each side.
W1: 75% of the maximum width of the original vehicle
Drawing 7-10
Rear edge of the car
Center of rotational
axle of rear wheel
Longitudinal
center line of
car
Overall
width of
the car
Extended line from the base of
the flat bottom
Drawing 7-11
3.3.10.2) Changes in bumper configuration accompanied by widening of fender width
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These changes in bumper configuration are permitted subject to the following conditions only.
In order to facilitate examination of the configuration change, participants must carry a template with
them.
1) Permissible area for the changes of front bumper configuration
This must remain within the area determined by the straight lines at an angle of 30° in relation to the
lines connecting base points P1 & P2 and the straight lines parallel to the longitudinal centerline of
the car which contact with the outermost perimeter of the bodywork (refer to Drawing 7-10).
Furthermore, R in some degree must exist at each of the intersection points when viewed from above.
However, the front bumper situated within the area defined under the relevant regulations must not
be in the shape of canard or similar to it (ledge shape extended longitudinally).
2) Permissible area for the changes of rear bumper configuration
2)-1 Part above a parallel plane passing 300mm above the flat bottom base.
the car which contact with the outermost perimeter of the bodywork (refer to Drawing 7-10).
2)-2 Part under a parallel plane passing 300mm above the flat bottom base.
When seen from above, modification of the rear bumper in this area is permitted if it remains within
the area determined by the rear axle center line and the line parallel to it at the rear edge of the
bodywork and the straight lines at an angle of 30°in relation to the latter at the points laying 665mm
from the longitudinal centerline of the car each side and the lines parallel to the longitudinal
centerline which contact with the outmost perimeter of the bodywork (refer to Drawing 7-11).
3.3.11) Fenders
1) Fender may be widened up to 1,950mm within the overall width of a car. The front part of the front
fender and rear part of the rear fender must be fit within the area defined under Article 3.3.10.2)
"Changes in bumper configuration accompanied by widening of fender width "when seen from
above.
The rear edge of the front fenders must not extend over the parting line at the front edge of the doors
(the dimension of front fender may not be increased in longitudinal direction).
Parting line at the front edge of the doors
Fender cannot be extended to the rear of
the line
Drawing 7-12
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2) The design of the fender parts which are extended is free, however opening made must respect the
provisions of Art. 3.3.3.2) "Opening on fender" of the present regulations and have radius of 5mm
or more at projected parts having acute angles on the outer surface of a car, the fender parts which
are not extended must have identical surface with the original vehicle.
3) When the fenders of the original vehicle have openings for intake and cooling for the engine, it is
permitted that the dimensions of the openings are altered or the openings are closed as a result of
extension of the fenders. However it is obligatory to respect the provisions of Art. 3.3.3.2) "Opening
on fender" of the present regulations even in the former case.
4) Bumper and fender construction where the bumper extends into the inside of the fender are permitted
only if this is the original vehicle design.
5) Fender must not protrude beyond the perimeter of the upper edge of the fender of the original vehicle
viewed from the side. However if the tire housing installed in accordance with the prescriptions of
3.3.12)"Tire housing" interferes with the fender, the curved part which contacts with the installed
tire housing may protrude from the perimeter of the upper edge of the fender and the relevant
projected part may be connected with its circumference smoothly (by smooth radius).
Projecting part as a result of
construction of the tire housing
Smooth radius
Smooth radius
Parting line of the fender of the
original vehicle
Drawing 7-13
6) If the original rear fender and rear pillar are of integral construction, the fender is considered to be
below the horizontal plane passing through the lower edge of the rear window.
3.3.12) Tire housing
3.3.12.1) In order to allow the tire housing to accommodate the front/rear complete wheel, an independent
tire housing which is formed by the planes inside of wheel arch must exist regardless of the structure of
the original vehicle. There are no restrictions on tire housing materials.
1) Tire housings must be installed within the area defined below, with the complete wheels in the straight
ahead position and the car in running order.
(1) Parallel to the bottom surface of the flat bottom, and above the plane passing through the wheel
center line: In the area within a radius of 410mm of the wheel rotational axle. The transverse
position (to the right and left of the car) is free.
(2) Parallel to the bottom surface of the flat bottom, and below the plane passing through the wheel
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center line: In the area delimited by the planes passing the center of the rotational axle of the
right and left wheels and parallel to the plane perpendicular to the bottom surface of the flat
bottom, and within 410mm to the front and the rear respectively. The transverse position (to the
right and left of the car) is free.
(3) The shape of the tire housing
(1) The shape of the tire housing is free.
(2) The tire housing and the bodywork structure which are situated less than 50mm above the
bottom surface of the flat bottom in the area of the tire housing situated behind the frontal
edge of the flat bottom and in front of the rear edge of the flat bottom must be covered by
the flat bottom when seen from its underneath.
Examples of the front tire housing
The angle
is free
Flat bottom
Flat bottom
Radius 25mm
Flat bottom
Examples of the rear tire housing
Rear tire housing
Rear tire housing
Flat bottom
Flat bottom
Rear tire housing
Radius 25mm
Rear tire housing
The angle
is free
Flat bottom
Flat bottom
Drawing 7-14
(4) Opening may be created on the aft part of the tire housing which is connected to the cut-out(exit
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hole) permitting the escape of air used to cool the brakes created under Art.3.3.3.2) "Opening
on fender".
(5) Creating opening is permitted for the purpose of passing sprung parts, driving device and ducts
for cooling the brakes and of extracting heat from the exhaust pipe.
2) If the tire housing of the original vehicle was constructed already beyond the size defined by 1) above,
it must be within the dimensions of the original vehicle.
3) However where the front edge or the rear edge of the tire housing interfere with the bulkhead,
modifications may be made solely in the area within a radius of 460mm of the front wheel axle
rotational center with the wheels in the straight ahead position for the front bulkhead, and in the area
within a radius of 410mm of the rear wheel axle rotational center for the rear bulkhead.
4) The side sill exists within the area defined by 3) above may be removed.
3.3.12.2) In order to build tire housing, it is permissible to remove original side rail-uppers and the
framework around it on condition that there is no decrease in the structural rigidity, except when any
upper attachment point of suspension struts is installed to the parts concerned.
3.3.12.3) Where the drive-shafts interfere with the side members, the parts concerned may be modified
within the smallest possible area. However in order to maintain the structural rigidity which might be
altered by the modification carried out, the modified parts must be reinforced.
3.3.13) Side skirts
Side skirts are permitted on condition that, and there are no restrictions on side skirts materials.
1) it is installed below the horizontal plane passing through the center of the front and rear wheel
rotational axles of the car in running order.
2) within the area (width) extended by the maximum vehicle width.
3) The front/rear edge and the lateral edges must have a radius of more than 5mm.
4) The outer surface of the side skirts may not enter the inside of the outer surface of the original vehicle.
5) Furthermore it must be connected to the flat bottom without any gap and also to the front/rear fenders.
3.3.14) Engine compartment
3.3.14.1) Radiator support and its supporting members may be removed.
3.3.14.2) Bonnet (including engine-cover), rear hatch gate and boot-lid
If the tire housing installed in accordance with the prescriptions of 3.3.12)"Tire housing" interferes
with the bonnet (including engine-cover), rear hatch gate or boot-lid , the relevant part which contacts
with the installed tire housing may protrude in a curved shape follows the upper edge of the tire housing.
The relevant projected part may be connected with its circumference and the fender smoothly (by
smooth radius).
3.3.15) Luggage compartment
The floor of the luggage compartment may be modified or removed but the ground may not be seen.
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1) If the floor of the luggage compartment is modified;
1.1) When any rear aerodynamic part does not exit under the floor:
(1) The shape shown in the drawing 7-15A is prohibited.
(2) The floor surface must be flat and parallel to the flat bottom (see drawing 7-15B).
(3) When the floor surface is flat and parallel to the flat bottom, it can be lowered by the level
of the flat bottom.
1.2) When rear aerodynamic part exists under the floor :
(1) When rear aerodynamic part under the floor exists to the rear edge of the car, the shape of
the floor surface situated above it is free (see drawing 7-15C).
(2) When rear aerodynamic part under the floor does not exists longitudinally to the rear edge
of the car, the shape of the floor surface behind its rear edge must be flat and parallel to the
flat bottom as well (see drawing 7-15D).
(3) Air must not flow in longitudinal direction between the rear aerodynamic part under the
floor and floor surface.
Flat bottom
Drawing 7-15
1.3) Regardless of existence of rear aerodynamic part under the floor, only the air passed through
radiator may flow in the space situated above the floor surface of luggage compartment. If the
air flows (in the space) over the lowest surface of the bodywork (floor surface of the luggage
compartment) and the purpose of that opening is the escape of air which passes through radiator
installed inside the luggage compartment etc., the cross section of the opening must be less than
the area of the radiator core.
2) When the floor of the luggage compartment is removed;
(1) It is permitted install a crushable structure in order that the influence resulted from these changes
against impact must be minimal.
(2) In order to provide greater rigidity for the bodywork, cross-members can be freely added.
3) If a safety fuel tank installed in the luggage compartment;
Appropriate steps may be taken to prevent the fuel tank from falling. This includes the addition
of structure by reinforcement- members to secure its safety.
3.3.16) Hard top for open cars
Provided the following conditions are observed, hard top for open car may be installed.
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1) Configuration: If the original open car has a soft top or a hard top as its optional parts, the hard top
which may be installed must maintain its configuration similar to the original.
2) Material: rigid and sufficiently fireproofing material and must be either of the followings, except the
attachments (including flanges);
(2) Carbon fiber material having honeycomb construction no less than 10mm thickness
3) The highest point: The highest point indicated in the 3- view-drawing of the catalogue of the vehicle
concerned should be regarded as the highest point of the car.
4) Fixation: There is no restriction on its fixation method. However fixing to homologated rollcages
may be authorized only if there is no need to carry out any modification to the rollcages.
3.3.17) Vehicle interior
With the exception of the luggage compartment, vehicle interiors must remain as they were in the
original vehicle (Any mechanical structural element must not exist other than that is originally installed
in the vehicle).
Modification and replacement of the dashboard (instrument panel) are permitted. But complete
removal of the dashboard (instrument panel) is not permitted.
Flexible air ducts made of non flammable material may be installed to the vehicle interior for the
purpose of cooling the driver and various auxiliary equipment(electrical equipment). It is also authorized
that the flexible ducts are connected with air scoops specified in Article3.3.19) "Auxiliary accessories"
of the present regulations, however it must not obstruct driver's visibility.
Oil tank installation to the vehicle interior (cockpit) is not permitted.
3.3.18) Reinforcement
Reinforcement of the bodywork (including bulkhead) is free provided it does not encroach on the
spaces inclusive of driver's and passenger's compartments.
3.3.19) Auxiliary accessories
Demisting devices and cockpit ventilation systems are free provided that the original ventilation
openings are remained and the outside shape is not significantly changed (Maximum protrusion 20mm).
3.4) Aerodynamic device
3.4.1) Front aerodynamic device
(1) The device may be installed under the bodywork within the area determined by the parallel line
max. 950mm forward of the line connecting the axle centers of right and left front wheel and the
straight lines at an angle of 30°in relation to the fore-mentioned parallel line at the points laying
460mm from the longitudinal centerline of the car and the lines parallel to the longitudinal
centerline which contact with the outmost perimeter of the bodywork. This area must also be
130mm or less above the base of the flat bottom.
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Front
edge of
the flat
bottom
Front wheel axle
centerline
Overall
width of
the car
Flat bottom
Front aerodynamic device
Height limitation at front
and rear edges
Drawing 7-16
(2) Materials are free.
(3) The frontal edge and the lateral edges should have a radius of more than 5mm if they are outermost
perimeter of the bodywork.
(4) Lower structure of the bodywork may be connected to the lower part of the fender which is situated
forward of the vertical plane passing through the foremost point of the front complete wheel.
(5) For the examination of (1), participants must carry a template with them.
(6) Flap (canard) may be installed in the area (Drawing 7-17);
(i)
below the horizontal plane passing 250mm above the bottom surface of the flat bottom of the
car;
(ii) forward of the front complete wheel and outside of the points P1 and P2 ;
(iii) inside the parallel line max. 950mm forward of the line connecting the axle centers of right
and left front wheel and the straight lines at an angle of 30°in relation to the fore-mentioned
parallel line at the points laying 460mm from the longitudinal centerline of the car and the
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lines parallel to the longitudinal centerline which contact with the outmost perimeter of the
bodywork.
(iv) be 120mm or less from the perimeter of the bodywork.
The longitudinal
centerline of the car
Overall width
75% of the
original car
Front
wheel axle
centerline
Overall
width of
the car
point Point P2 at
the opposite side
Section
Max.
Canard
Flat bottom
Max.
Drawing 7-17
3.4.2) Rear aerodynamic device
As a rear aerodynamic device, either a rear air spoiler or a rear wing may be installed provided the
followings are observed:
1) Number of the device should be one unit.
2) The wing should be one and any part of the aerofoil section should be able to fit in a 400mm×150mm
rectangle (including gurney-flaps, excluding supports and end plates).
3) Its height should be limited by the top of the ceiling except optional parts(1,100mm above the bottom
surface of the flat bottom).
4) The maximum width is 1,900mm (including supports and end plates).
The area determined by the line parallel to the rear axle center line at the rear edge of the bodywork
and the straight lines at an angle of 30°in relation to the line at the points laying 665mm from the
longitudinal centerline of the car each side and the lines parallel to the longitudinal centerline which
contact with the outmost perimeter of the bodywork
(refer to Drawing 7-18) is to be regarded as
the outermost edge of the perimeter of bodywork, and the above mentioned rear device may be
installed within this extent.
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Rear wheel axle
centerline
Rear wing
Drawing 7-18
5) It should be placed above the perimeter of the bodywork and the parting line of the rear fender when
viewed from the side, or on the surface of the boot-lid (engine-cover).
(It is not permitted to install any aerodynamic device onto the rear fender.)
6) It should be situated behind a plane vertical to the bottom surface of the flat bottom and passing
through the center of the rear wheel rotational axle.
7) The frontal edge and the lateral edges including end plates should have a radius of no less than 5mm.
8) The shape and materials are free. When installing the device to the boot-lid, it is permissible to install
reinforcements to the inside of the boot-lid to provide greater rigidity for the fixation of supports.
9) The boot-lid and rear hatch gate should be able to be opened and closed without removing any
structural part.
3.4.3) Aerodynamic devices beneath the rear floor
It is permitted to add a completely flat inclined panel without openings under the following
conditions.
Under the floor no less than 350mm behind the center of the rear wheel rotational axle and 650mm
from the longitudinal center line of the car on each side, it is permitted to install only aerodynamic parts
mounted to the original vehicle or a completely flat inclined panel without openings (inclined panel)
under the following conditions. Neither the said aerodynamic parts nor the inclined panel may be
installed, but they can not be installed together.
However if any structural part of the car interferes with the inclined panel when the frontal edge of
the inclined paned is moved, the part concerned may protrude in a shape of rectangular parallelepiped
which is parallel to the surface of the flat bottom.
Materials are free.
Regardless of the existence of the inclined panel, free for the area beyond 650mm from the
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longitudinal center line of the car on each side and aft of the plane vertical to the bottom surface of the
flat bottom and passing through the center of the rear wheel rotational axle, and also under the parallel
plane passing 300mm above the bottom surface of the flat bottom.
1) Between the vertical planes, one passing through the rear edge of the flat bottom (a vertical plane
passing through the center line of the rear wheel rotational axle) and the other passing through the
rearmost point of the bodywork.
2) Maximum width of the panel is 1300mm and it shall be symmetrical in relation to the longitudinal
3) No part of the panel may be situated more than 150mm above the flat bottom.
4) Exhaust pipe and air-cooled cooler radiator are permitted to be installed.
Flat bottom
Inclined panel
Drawing 7-19
5.1) Shielding is optional and may be installed on the lateral part of the inclined plate. Materials and the
shape are free when it is installed.
5.2) If there is any removable auxiliary part such as a grill at the rear of the original vehicle, it may be
removed providing the following conditions are respected:
When a bodywork part exists under the auxiliary part and no gap exists between it and the inclined
panel, the space created after the auxiliary part is removed should be covered according to the Art.
3.3.3.5) "Openings for the rear part of the bodywork" of the present regulations.
6) The junction between the rear edge of the flat bottom and the foremost point of the inclined panel
must be continual and may have a radius of up to 25mm.
7) Vertical fins may be installed under the following conditions, Materials are free:
(1) They remain parallel to the longitudinal center-line of the car.
(2) They exert no aerodynamic influence.
(3) Maximum 4 fins
(4) Vertical fins may be extended from the rear edge of the panel to the rear, however the highest
edge within the width of 1,300mm must not be more than 150mm from the flat bottom and the
rear edge must be situated inside the outline of the car.
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When the upper extended part is fixed to the bodywork openings must be made according to the
Drawing 7-20.
The ground must not be seen when a
boot-lid(trunk) or a hatch gate is opened
The lower surface of the
bodywork structure
Space
Inclined panel
Vertical fin
Vertical fin extended from the rear edge of
the panel to the rear
bodywork structure
Bracket to install vertical fin extended
from the inclined panel to the rear
Circle of the
diameter of
50mm
Inclined panel
Vertical fin
bodywork structure
Inclined panel
Vertical fin
Drawing 7-20
8) Openings may be made into the inclined panel for the following reasons:
(2) Extraction of heat from the exhaust pipe.
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- The holes must follow the shape of exhaust pipe
- Maximum diameter is 50mm.
(3) Sensor use
Up to 2 openings with the maximum dimension of 20mm x 50mm
9) If rear aerodynamic part is installed under the floor and its dimension from the longitudinal center
line of the car to the right and left is less than 650mm respectively, it is not permitted to install any
structure except exhaust pipe and oil cooler (including its lines) in the area defined by its edge and
by the lines situated 650mm from the longitudinal center line of the car.
Article 4: Weight
4.1) Minimum weight
Minimum weight must be respected as laid out in the Appendix 2 of this Chapter Section. The JAF
may change the minimum weight requirements with notice in advance at any time during the season in
order to provide equality of performance.
4.2) Ballast
It is permissible to install one or more ballast to fulfill the requirement of the minimum weight. The
position and the installation method of the ballast are free, but both the ballast and the bodywork part to
which the ballast is fixed must have sufficient strength.
Article 5: Engine
5.1) Type and position of engine
An engine from another model of car can be mounted if it derives from the homologated or registered
vehicle of the same manufacturer.
The mounting position, location and orientation of the engine are free provided the engine is situated
fore of the front bulkhead or aft of the rear bulkhead.
The mounting position of the engine may not be altered from that of the original vehicle. The
position, location and orientation of the engine in the original engine compartment are free. However
the position, location and orientation of the engine of the car manufactured before 2016 are free
provided it is installed fore of the front bulkhead or behind the rear bulkhead.
5.2) Engine modifications
5.2.1) Cylinder capacity
Modifications to cylinder capacity are permitted.
5.2.2) Supercharging device
Free.
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5.2.3) Cylinder head and cylinder block
Reinforcement of the head and block is permitted.
5.2.4) Crankshaft and connecting rods
Free.
5.2.5) Bearings
Free provided that the original type of the bearing (plane bearing, roller bearing, etc.) is maintained.
5.2.6) Cylinder head gasket
Free.
5.2.7) Camshaft and valves (including valve springs)
Modifications to camshaft position / number and changes to the driving system are not permitted
however, the other elements are free.
Only when variable valve timing is installed to the original engine and its mechanism remains
identical to that original one, it is permitted to use it.
5.2.8) Pistons, piston pins, and piston rings
Free.
5.2.9) Flywheel
Free.
5.2.10) Ignition system
Free.
5.2.11) Lubricating system
Free other than the restrictions defined below.
When viewed from above, the oil cooler must not protrude from the vehicle perimeter. If the oil
cooler is installed outside the vehicle, it must be positioned below the horizontal plane passing through
the wheel rotational center of the vehicle in running order.
5.3) Air intake system
Free other than the restrictions defined below.
The use of water injection devices, variable valve timing, variable inlet ports, and air intake
adjustment devices is allowed only if these devices were part of the original vehicle or the original
engine.
The use of a variable intake trumpet is not permitted.
5.3.1.1) Air restrictor
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All cars must have either 1 or 2 air restrictor(s) made of metal with a tube(s) having circular section(s)
maintained for a minimum length of 3mm. All air admitted to the engine must pass through the air
restrictor(s). When all the intake air is forced to stop upstream of the air restrictor(s), engine must be
immediately stopped.
5.3.1.2) Air restrictor diameter
Air restrictor diameter must be maintained as specified in the Appendix 2 of this Chapter Section.
Air restrictor diameter must comply with the prescribed value at all time during an event.
The JAF may change the air restrictor diameter requirements with notice in advance at any time
during the season in order to provide equality of performance.
5.3.1.3) Supercharged engine
The air restrictor must be situated at a maximum of 50mm upstream of the vertical plane passing
through the most upstream extremities of the supercharger wheel blade, otherwise in the middle of an
airtight and one piece cone of 7 degrees minimum, which is fitted directly to the inlet of the housing.
If an air restrictor and the cone are installed as an integrated part, such part must be joined to the
housing side of the supercharger without any gap.
The JAF may impose restrictions on supercharging pressure with notice in advance in order to
provide equality of performance.
Air restrictor
Integrated part
The housing of the supercharger
Drawing 7-21
5.3.1.4) Normally aspirated engine
It is obligatory to equip an air box and the air restrictor must be installed to an air inlet of the box.
The air box must satisfy the following conditions:
1) It must not exceed 1,000mm x 500m m x 500mm
2) Intake ducts in front of air box are free provided the external appearance of the car is not changed.
The internal structure and also the material of the air box are free.
3) When all the intake air is forced to stop while the engine is running, the engine must stop and the
air box and those intake ducts in front of it must have sufficient rigidity not to be damaged or
failed.
5.3.2) Air restrictor exemptions
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Vehicles equipped with a naturally aspirated reciprocating engine having a cubic capacity of up to
2,000cc where all the intake air is delivered through a single aperture, no air restrictor installation is
required.
5.3.3) Intake temperature
5.3.3.1) Intercooler
Intercoolers for cooling the intake air including its mounting position and piping are free.
But their only function must be to channel air.
Apart from intercoolers, any device, system, procedure, construction or designs which have the
purpose and/or effect decreasing the temperature of air supplied for the engine are forbidden.
5.4) Cooling
Water radiators are free, as long as its function is identical to the one installed to the original vehicle.
Water pumps are free.
For the purpose of cooling the water radiator, oil cooler and each engine part, only air is permitted
and other cooling method by injection or spraying of any substance other than air into them is prohibited.
Heat exchanger can be used.
Flexible air ducts may be installed in the engine compartment to cool auxiliary equipment of the
engine.
5.5) Exhaust system
The exhaust system is free. However,
1) at least one catalytic unit must be installed through which all exhaust gases should pass. The unit
must be approved by JAF and the application must be submitted no later than 2 months before the
competition in which the unit is used for the first time;
2) variable exhaust systems are not permitted.
Exit of the exhaust should be as follows for the cars with a lateral exhaust exit:
1) Minimum height: the lowest point of the exit must retain the minimum ground clearance without fail.
2) Maximum height: the highest point of the exit must not exceed the parallel plane passing 300mm
above the bottom surface of the flat bottom.
5.6) Rotary engines
5.6.1) Supercharging is not allowed for 3-rotor engines.
5.6.2) 3-rotor engines must be equipped with air restrictors specified in the Appendix 2 of this Section.
5.6.3) On vehicles equipped with a naturally aspirated rotary engine where all the intake air is delivered
through a single aperture, no air restrictor installation is required.
5.6.4) Type of rotary engine port
Free.
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Article 6: Lines and pumps, and fuel tanks
Free as long as Articles 6.1), 6.2) and 6.3) are observed.
6.1) Fuel tanks
It is obligatory to install a safety fuel tank.
It is obligatory that a flexible joint be used for the junction of the fuel tank and fuel filler neck, which
can allow bodywork deformation in some degree and avoid any leakage of fuel.
6.1.1) Location of Fuel Tanks
All safety fuel tanks must be situated in the original position or between the front and rear wheel
center lines (inside the wheelbase). They must conform to the following conditions.
1) It must be surrounded by an impact absorbing structure of at least 10mm thick.
2) It is permitted to cut the cockpit floor in order to install a safety fuel tank.
3) It must be insulated by a rigid and non-flammable fire wall from driver and the engine compartment,
which is made of the material defined by 3.3.5.2) "Rear bulkhead" 3). For this purpose, the bulkhead
defined under Article 3.3.5) "Bodywork (monocoque structure) and bulkhead" or a floor without
openings may be regarded as a fire wall. The container for the safety fuel tank is not considered to
be a fire wall.
If the bulkhead extends vertically from the floor of the vehicle to the ceiling, a window of the smallest
possible area may be installed to the bulkhead to permit vision to the rear of the vehicle. The window
must be made of laminated glass.
4) Leakage of the fuel must not be accumulated and careful attention should be paid for it so as not to
go into the cockpit.
6.1.2) The use of self sealing breakaway valve for all fuel lines between the fuel tank and the engine is
considered desirable. This valve must operate at less than 50% of the load required to break the fuel line
fitting or to pull it out of the fuel tank.
6.1.3) Fuel supply system
It must not be installed in the cockpit and outside of the bodywork. Except for the fore-mentioned
condition, the system is free.
6.1.4) Unless the tank fillers are connected directly to the tank, it is recommended that a valve supplied by
the tank manufacturer be installed at the top of the tank. The valve should permit sealing the fuel tank
in the event of the filler being knocked off during an accident.
6.1.5) Position of the filler
1) Minimum height: The center of the filler must not be lower than the plane passing through 595mm
2) The distance between the center of the filler and the edge of the exhaust exit must be 1000mm or
more in plain view.
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the center of the filler
Flat bottom
Exhaust
exit
Filler
Drawing 7-22
6.2) Fuel capacity
The maximum amount of fuel which may be carried on board is 100 liters.
The JAF may reduce the total fuel tank capacity with notice in advance.
6.3) Number of fuel tanks
Multiple fuel tanks may be used as long as the maximum capacity of the tanks does not exceed that
specified in Art. 6.2) "Fuel capacity" above. However, only 1 collector tank is permitted.
6.4) Cooling of fuel
It is permissible to install cooling device to the fuel supply piping mounted on the vehicle for the
purpose of decreasing the temperature of fuel. The only method allowed for cooling fuel is air-cooled
method by natural air stream.
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Article 7: Electrical Equipment
7.1) Battery
Only sealed batteries are permitted. Insulation to prevent shorting must be installed.
The battery may be mounted anywhere except in the area of the driver's seat.
There are no restrictions on battery make and capacity.
7.2) Lighting
Indicators, by which the driver may recognize whether the headlight and/or the direction, must be
fitted.
7.2.1) Headlights
1) Headlights must remain in their original position. Their configuration and function of the original
vehicle must be maintained. The main optical axis must be to the front. Brightness (light intensity)
must be at least equal to that of the original vehicle's headlights so that the lightening can be
recognized by the drivers of the cars running in font and the officials around the track. Right and left
lights must not be illuminated by turns.
2) Headlights must have yellow or amber colored covers.
3) If it is not possible to install the same lighting unit(except luminous valve) as that was installed on
the original vehicle, the diameter of the surface of headlight lens must be at least 10cm.
4) It is authorized to alter a light source for the purpose of increasing illumination (or luminous
intensity).
5) If the vehicle is originally equipped with retractable headlights, the retracting mechanism may be
removed and modifications with transparent materials may be carried out so as to lighten the front
of the vehicle.
7.2.2) Other lights
7.2.2.1) Tail light and brake light
Tail light and brake light must have the same configuration as those of the original vehicle.
Brightness (light intensity) of these lights must be equal to or greater than that of the original lights.
7.2.2.2) Direction indicators
The lightening of indicators must be recognized by the drivers of the cars running in front/behind
and the officials around the track. The diameter of the indicators' lens surface is required to be at least
30mm.
There is no restriction on side markers including its removal.
7.2.2.3) Rain light
One of the following rain lights defined below must be fitted to the rear of the car which is in working
order throughout of an event.
(1) Rain light that is approved in accordance with ECE R38 road standard (or an equivalent or stricter
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standards from another country).
(2) One rain light approved by the FIA ( Technical List No.19).
(3) Rain light which has an equivalent brightness as (2) above and comply with the following rules:
- The surface of the lens that is visible from the rear of the car is 30 ㎠ minimum and 140 ㎠
maximum.
- Luminous intensity is no less than 150cd and no greater than 300cd.
- Luminescent color is red only.
The rain light must fulfill the following conditions:
- Emission pattern of the light is solid only.
- Independent circuit should be secured for the light apart from the other optical circuit.
- It shall be perpendicular to the centerline of the car and faced toward the rear of the car.
- It should be clearly visible from the rear.
- It should be installed within 10cm from the centerline of the car.
- It should be at least 35cm above the bottom surface of the flat bottom.
- The surface of the lens should be at least 45cm behind the centerline of the rear wheels when
measured parallel with the bottom surface of the flat bottom.
- It should be able to be switched on by the driver when seated normally in the car.
The three measurements are taken to the center of area of the lens.
7.2.2.4) Other lights
Ducts can be connected to openings which are created by removal of the original lights.
7.2.3) Wiper
It is permissible to change the front window wiper construction. However at least one wiper must be
equipped and it must be able to be operated by the driver seated and activated effectively at any time
during an event.
Article 8: Transmission
8.1) Drive system
Changes in drive system are permitted regardless of the system used in the original vehicle.
Kinetic Energy Recovery System may be used providing the system is submitted to JAF and
approved according to the "Supplementary regulation for Kinetic Energy Recovery System".
8.2) Clutch
Free provided the conditions set out in the Article 2.1.2) "Control function restrictions" are respected.
8.3) Transmission and transmission control lever
The gearbox must comprise a maximum of 6 ratios and a reverse gear. Mounting position is free.
Use of a paddle sift system is authorized.
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8.4) Final drive system and differential
The viscous clutch is permitted provided that it is not controllable when the car is in motion.
8.5) Propeller shaft and drive shaft
Free.
8.6) Cooling
Only air cooling of the transmission is permitted. Injection or spraying of any substance other than
air to cool the brakes is prohibited.
Mounting of oil cooler is free.
Article 9: Suspension and steering
9.1) Suspension type and installation
Suspension type on the original vehicle may be freely modified and altered.
However, even if the suspension fixation point on bodywork side is changed, the suspension must
work normally when the engine is dismounted.
9.2) Anti-rollbar
There are no restrictions on anti-rollbar including their installation brackets.
Adjustment of anti-rollbar can be made mechanically only by driver when the car is in motion. This
must not be adjustable by any other means than the said method.
9.3) Axles
There are no restrictions on axles including spindles. They may be changed into Center locking type.
9.4) Springs
There are no restrictions on springs including the addition of supplementary springs provided the
conditions set out in the Article 2.1.2) "Control function restrictions" are respected.
9.5) Shock absorbers
There are no restrictions on shock absorbers provided the conditions set out in the Article 2.1.2)
"Control function restrictions" are respected.
9.6) Suspension arms
All suspension arms must be made of metal.
9.7) Chromium plating
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Chromium plating of steel suspension arms is not permitted.
9.8) Steering
Steering wheel, steering system (steering gearbox, link) and steering wheel must be connected solely
by mechanical means.
Power steering is permitted to use only if it is a single system without a programmable control.
Open type steering wheel is forbidden. A quick release system must be installed on the steering wheel
and its method must be of the type pulling a concentric flange situated on the steering column.
The shape of the steering wheel is free.
It is recommended to install a steering column with an impact absorbing device.
Article 10: Brakes
10.1) Brake system
The brake system is free, provided the conditions set out in the Article 2.1.2) "Control function
restrictions" are respected.
However, there must be no sensors or devises other than a fluid pressure sensor, a brake light switch
and a proportional brake valve on the lines between master cylinder and caliper.
Parking brake installation is optional.
10.2) Brake calipers
A single caliper is allowed for each wheel. Each caliper may have up to 6 pistons. The cross-section
of each piston must be cylindrical.
10.3) Brake cooling
Only air cooling of the brakes is permitted. Injection or spraying of any substance to cool the brakes
is prohibited. However, the use of brake caliper cooling system by a liquid circulation is permitted.
Air ducts for cooling the brakes may be installed. However, these ducts must not change the
bodywork configuration above the bumper and not permit the aerodynamic effect beneath the vehicle
between the front and rear wheel center lines (within the wheelbase).
There is no restriction on the number and size of air ducts used to cool each brake assembly.
Air ducts made of titanium are not permitted. Other than this, there is no restriction on air duct
material.
10.4) Brake discs
Maximum one brake disc made of ferrous material per wheel is permitted.
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Article 11: Wheels and tires
11.1) Dimensions
11.1.1) Complete wheel maximum diameter and maximum width
Maximum diameter: 28 inches
Maximum width: 14 inches
11.2) Wheel material
Wheel material is aluminum only and the minimum weight of one wheel is 10kg. However balance
weight including air valve is not included in the weight calculation.
Accessories of wheels are permissible only if they do not exceed the maximum width of the complete
wheel and are secured by bolts etc.
11.3) Wheel attachment
Wheel attachment is free, if a single center nut, a red or dayglo orange safety spring or a
device/system performing the same function as the said spring must be installed to each wheel when the
car is in motion. The safety spring or the similar device mentioned above must be installed after each
wheel change.
11.4) Pneumatic jack
Pneumatic jack installation is permitted. However, the installation of a compressed air bottles to the
vehicle is prohibited.
Article 12: Safety equipments and devices
All the regulations concerning safety are completed by adding the following to the Chapter 4 "Safety
regulations for homologated cars and registered vehicles" and applied.
12.1) Safety belts
The wearing of two shoulder straps, one abdominal strap and two straps between the legs is
compulsory.
Safety belts must comply with FIA standards 8853/98.
Each strap of the safety belt must have its own fixation point on the bodywork. Two abdominal straps
for right and left respectively can be prepared as long as they have the same homologation numbers and
the two abdominal straps on one side may be attached together by one attachment point on the body.
12.2) Rear view mirrors
It is permitted to remove an inside mirror or replace it with any other system of equivalent efficiency,
when the bulkhead extends from the floor to the ceiling under the prescriptions mentioned in 6.1.1), or
when a partition window serves as a bulkhead as defined under the Art.17 "Protection against fire" of
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the Chapter 4 "Safety regulations for homologated cars and registered vehicles", regardless of the
provisions under Art.7 "Rear view" of the Chapter 4 "Safety regulations for homologated cars and
registered vehicles". However, in this case, the rear view must be secured, and outside mirrors of the
original vehicle or having no less than 100 ㎠ must be mounted on the both side of the outer surface of
the bodywork.
12.3) Seats and Headrest
It is obligatory that FIA homologated competition seats (Standards 8855-1999 or 8862-2009) which
have a reinforcement part around the driver’s head padded with energy absorbing and non flammable
material be used.
The driver's seat can be moved towards the center of the car unless it does not go beyond the
longitudinal center line of the car.
Headrest must be able to retain the driver's head wearing a helmet and must not have it move
rearward during acceleration. The driver’s head must not be caught between the headrest and rollover
bars. It is recommended that the distance between the sides of the headrest should not exceed 400mm
and that energy absorbing material of minimum 20mm is fixed to the both sides.
12.4) Relation between seats, rollcage and lateral protection structure
The following dimensions should be respected within the plane perpendicular to the centerline of a
car and to the surface of the flat bottom including the lowest point of the seat at the center of it.(Drawing
7-23) However when the seat has a sliding system, the position of slide can be optional.
1) The distance between the center of the seat and lateral roll bar should be 950mm or more.
2) Between the center of seat and the lateral protection structure, horizontal distance should not be less
than 250mm and the difference of their vertical height should not be greater than 430mm.
Cross section of lateral roll bar
The lowest point
of the seat at the
seat’s center
The lowest point of the
seat at the seat’s center
Aria for lateral
protection structure
Flat bottom
Side view of a car
Drawing 7-23
12.5) Relation between driver’s helmet and roll cage
When a driver is seated in his normal driving position and looks straight ahead, roll cage must not
be existed within the range shown in the Drawing 7-24 when seen from the side.
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Line contacts with the highest point the
driver’s helmet when he is seated in his
normal driving position and looks straight
ahead and parallel to the flat bottom
Line contacts with the rearmost point the
ahead and perpendicular to the flat bottom
Rollcage can not be
exited within the
meshed part
Side view of a car
Flat bottom
Drawing 7-24
12.6) Elements between the door and the driver's seat
Between the door and the driver's seat, no mechanical components may be installed other than side
bars of the rollcage.
However, the impact absorbing structure, the knee pad and the water-supply bottles are not
considered as mechanical components.
12.7) Frontal (back) protection structure
For the purpose of installing a crushable structure in the front of car, modifications are permitted.
But these changes must be limited to the smallest possible area on the side rails situated fore of the
frontal edge of the front complete wheels.
When a tubular structure defined under the Article 3.3.6) "Bodywork structure fore of the front
bulkhead and hind of the rear bulkhead" is installed, a crushable structure which satisfies the following
requirements must be installed:
1) The structure mounting position
Forward of the frontal tubular frame. Mounting the structure to the rear part of the frame is not
obligatory (optional).
2) Impact resistance
The average deceleration of the car must be less than 25G and must not exceed the maximum
deceleration 60G for more than 3ms when a frontal impact test is carried out.
For this test the car's
weight must be 1,500kg. The car shall collide head-on (full overlap) by at a velocity of 12metre/sec.
3) Dynamic crash test
A unit of crushable structure on a trolley is subjected to a dynamic crash test. A certification with a
signature of the person in charge of the testing laboratory must be issued and its copy must be
submitted to JAF.
It is not necessary to present a copy of the verification every year unless the vehicle type and its
design remain the same.
12.8) Lateral protection structure
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1) In order to absorb impact, inside the door of driver's side should be either filled with non-flammable
shock absorbing material and/or made up of crushable structure except when a rollcage structure
having three additional lateral protection bars according to the Drawing 7-25 is constructed. In that
exceptional case it is recommended to perform certain measures such as increasing the thickness of
the door outer panel.
Drawing 7-25
2) If the door of the driver's side remains the same as that of the original vehicle, original energy
absorbing structure located inside of the door may not be removed and the additional bar of which
material and dimensions are the same as those of the rollbar specified by the prescriptions of
Art.253.8.2.2.5.2 of the Appendix J must be mounted.
3) Furthermore, if the material of the door was changed, the door bar specified in Art.253.8.2.2.5.2 of
the Appendix J must be added.
However, if the door bar is not comprised of JAF/FIA rollcage, it is not obligatory to comply with
above 2) and the relevant prescriptions.
4) It is permitted to install an impact absorbing device between the door of driver's side and the rollcage.
12.9) Cockpit exit time
When the driver escapes from the cockpit in an emergency from his normal driving position, the
structure must allow the driver to get out of the car within 7 seconds from the door of the driver's side
and 9 seconds from the door of the passenger's side.
12.10) Extinguishing equipment
Installation of the automatic extinguishing equipment defined by Art.253.7.2 of the Appendix J is
compulsory.
Article 13: Other requirements
13.1) Guards and Supports
Installation of radiator guard, tank guard and sump guard is permitted. However the prescriptions
defined under the Article 3.3.6)"Bodywork structure fore of the front bulkhead and hind of the rear
bulkhead" must be satisfied.
Other than magnesium, there is no restriction on materials.
13.2) Handicap weight installation devices
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In order to enable the handicap ballast to be installed, weight installation device (rigid construction)
must be equipped at the place where scrutineers of the event concerned can easily check it.
Article 14: Final Text
The final text for these regulations shall be the Japanese version should any dispute arise over their
interpretation.
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Appendix 1
Article 2 2.1.2) Examples of prohibited systems according to the restrictions
on control functions
Prohibited system etc.
1
Automatic gearbox
2
Power actuated clutch
3
4
Electronically or automatically adjusted final drive differential system (ex.: Differentials with
air pressurizing or hydraulic slip control with electronic control and / or outer pump)
Electronically or automatically adjusted shock absorber, suspension or ride height adjustment
5
Four-wheel steering
6
Moveable ballast
7
Electronic control systems with closed-loop circuit other than engine
8
9
Devices that allow a driver to adjust shock absorber and suspension springs from the driver's
seat when the car is in motion
Telemetry
10
Active suspension
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Appendix 2 : Minimum vehicle weight and air restrictors
Cubic
Capacity Div.
（cc）
<=2,000cc
2,000cc<
<=2,500cc
2,500cc<
<=3,000cc
3,000cc<
<=3,500cc
3,500cc<
<=4,000cc
4,000cc<
<=4,500cc
4,500cc<
<=5,000cc
5,000cc<
<=5,500cc
No.
（mm）
Min. weight Div. （kg）
1,100
1,150
1,200
Installation Exemption
1
42.90
43.77
44.66
2
30.66
31.28
31.91
1
41.43
42.28
43.13
2
29.61
30.21
30.82
1
40.49
41.31
42.15
2
28.98
29.57
30.17
1
39.86
40.67
41.50
2
28.46
29.04
29.63
1
39.45
40.25
41.06
2
28.15
28.72
29.30
1
39.03
39.82
40.63
2
27.83
28.40
28.97
1
38.71
39.50
40.30
2
27.62
28.18
28.76
1
38.30
39.07
39.87
5,500cc<
2
27.31
27.86
28.43
* For Supercharged engine the capacity will be multiplied by the 1.7
coefficient and the section corresponds to the result in the table will
be applied.
***
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2016 JAF Grand Touring Car 300 Mother Chassis（JAF-GT300MC） Technical Regulations
2016 JAF Grand Touring Car 300 Mother Chassis (JAF-GT300MC)
Technical Regulations
Section 2: Grand Touring Car 300 Mother Chassis (JAF-GT300MC)
Article 1: Vehicle
1.1) Eligibility as an original vehicle
Cars produced by an automobile manufacturer, comply with legal requirements for road use and
satisfy either of the following conditions:
(1) homologated in FIA Group N/A/GT3/GT2/GT1, JAF Production Touring Cars or Special Touring
Cars,
(2) registered with JAF as registered vehicles.
(3) approved by JAF.
1.2) Original engine
An engine which is produced by its original manufacturer and is legal for road use, and admitted by
FIA and/or JAF.
1.3) Optional parts
The use of the optional parts which are mentioned in the FIA and/or JAF homologation form or the
JAF-GT main specifications register form of the cars registered with JAF is authorized.
Article 2: Regulations
2.1) Modifications
Any modifications which are not permitted in this Section are prohibited.
General prescriptions and Safety Equipment
Cars must comply with the following requirements of Appendix J. Art.252 "General prescription" and
Art.253 "Safety Equipment", which are not already covered in these regulations.
- 252.1) General remarks
- 252.2) Dimension and Weight
- 252.3) Engine
- 252.4) Transmission
- 252.5) Suspension
- 252.6) Wheels
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- 252.7) Bodywork / Chassis / Bodyshell
＊ Replace Art.252.7.3 "Cockpit" by the following text.
・Cockpit
The cockpit is that volume of the vehicle separated from the rest of the vehicle by fixed front
and rear bulkheads.
For 2-volume vehicles, the cockpit is that volume between the front bulkhead and the bulkhead
behind the rear edge of the rear-most seat. Remaining inner space behind that is referred to as
the luggage compartment.
The bulkheads must be constructed of highly flameproof rigid materials.
The cockpit must be completely insulated by the bulkheads from the engine compartment, fuel
tank, oil tank, gearbox, propeller shaft, and all joints of piping and tubing (connecting these
areas). Any and all devices/substance that is potentially dangerous to the vehicle driver must be
installed outside of the cockpit (on the other side of the bulkhead).
Only the following accessories may be installed in the cockpit.
* Spare wheels
* Tools
* Spare parts
* Safety equipment
* Communication equipment
* Ballast (if permitted)
* Windscreen washer water container
* Equipment for cooling suit
On 2-volume vehicles, the oil tank may be installed to the luggage compartment provided that
bulkheads are used to protect against oil leakage and sparking.
- 252.8) Electrical system
- 252.9) Fuel - Combustive
＊ Refueling tank must comply with drawing 252-7 with fuel hose of maximum 5m in length, but
flow restrictor is not mandatory.
- 252.10) Brakes
- 253.1) Dangerous car
- 253.2) Optional device
- 253.3) Lines and Pumps
- 253.4) Safety of braking and Steering systems
- 253.5) Additional fasteners
- 253.6) Safety belts
- 253.7) Extinguishers - Extinguishing systems
- 253.8) Safety cages
- 253.9) Rear view
- 253.10) Towing eye
- 253.11) Windows / Nets
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＊ Except for the following text
"The windows must be certified for road use, their marking standing as proof."
Anti-dazzling treatment may be applied as a strip along the upper edge of the glazed surface.
The width of the strip must not exceed 100 mm.
- 253.12) Safety fixing device for Windscreen
- 253.13) General circuit breaker
＊ Replace text "As for the outside, the triggering system of the circuit breaker will compulsorily
be situated at the lower part of the windscreen mounting of the driver’s side for closed cars" by
"As for the outside, the triggering system of the circuit breaker will compulsorily be situated at
the lower part of the windscreen mounting of the opposite side of driver’s side for closed cars"
In vehicles whose design makes it impossible to install the circuit breaker close to the lower part
of front windscreen mounting bracket, the circuit breaker may be installed outside either of the
passenger side center pillar or the quarter pillar, which permits operation from outside.
- 253.14) FIA approved safety fuel tanks
- 253.15) Protection against fire
- 253.16) Seats, attachments and supports
- 253.17) Pressure control valves
However, if the prescriptions which have the same meaning as those of the above Articles are defined
in this Section, prescriptions in this Section should be obeyed.
2.1.1) Material restrictions
2.1.1.1) Composite material (Including carbon and aramid fiber)
If only the use of the material is authorized in this Section or the use of the material is standardized
on the specific parts or areas of the original vehicle and engine, these composite materials can be used
in the relevant parts or areas.
2.1.1.2) Titanium and ceramics
1) If the use of these materials is standardized on the specific parts or areas of the original vehicle and
engine, these materials can be used only in the relevant parts or areas.
2) The use of these materials is permitted for the following parts:
(1) brake caliper pistons
2.1.1.3) Aluminum alloy
The use of aluminum alloy which has a modulus of elasticity greater than 80Gpa is forbidden except
for brake calipers.
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2.1.1.4) The other materials
The use of a material with a specific gravity greater than 12.0 is forbidden.
2.1.2) Control function restrictions
1) Any automatic or electronic chassis control system or function, excluding anti-lock brake system
and traction control system which are submitted to and approved by the JAF, is forbidden, even if
the original vehicle has it. This includes the systems listed in the Appendix 1 of this Section.
A simple open-loop electrical switch activated by the driver acting on a system is not considered
to be electronically controlled.
2) It is permitted to use (add) a speed limiter in order to comply with the speed limit in the pit lane.
2.2) Compliance with the rules and regulations
It is the duty of each competitor to give an explanation and accept any checks at the request of the
scrutineers and the Steward of the Meeting of the event concerned in order to satisfy them that his car
complies with the rules and regulations in their entirety at any time during an event.
2.2.1) Measurements
During the event, all required measurements will be made at the location specified by the chief
scrutineer and with measuring instrument and apparatus which will be provided by the event organizer.
No protest can be accepted against these measurement site, measuring instruments and/or equipment,
and measurement methods.
Article 3: Bodywork and exterior dimensions
Save the modifications authorized in this Section, dimensional specifications of the original vehicle
mentioned in the homologation form and documents in relation to the registered cars and also their outer
shapes without bolts for fitting must be maintained.
3.1) Dimensions
3.1.1) Overall length
The overall length of the car must not exceed the sum total of the dimensions of the overhang and the
wheel base permitted under Art.3.1.3) below.
3.1.2) Maximum height
The dimension from the bottom surface of the flat bottom to the top of the roof (roof reference plane
without local projecting shape, roof rail and auxiliaries such as antenna) must not be less than 1,100mm
when measured perpendicular to the bottom surface of the flat bottom. In order to comply with this rule,
it is permitted to remove the side sill and the floor, and downward raise of the side sill and moving of
the position of the floor are also permitted.
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3.1.3) Overhang and wheel base
1) Front overhang
The overhang may be extended up to 950mm. However it must not be extended more than 120mm
from the frontal edge of the front bumper of the original vehicle. If the overhang of the original vehicle
is greater than 950mm the length of the overhang of the original vehicle is the maximum dimension.
However for the front under panel defined in 3.4.1) approved by JAF, its frontal edge must be 950mm
maximum from the center of ther front wheel axle.
2) Wheelbase
The wheelbase is 2,750mm+/-10mm.
If the wheelbase of the original vehicle is elongated or contracted in order to comply with the
dimension of 2,750mm+/-10mm, it must be adjusted fore of the A pillar and/or behind the C pillar.
3) Rear overhang
When the dimension of the rear overhang of the original vehicle is less than 950mm, it may be
extended up to 950mm.
If the overhang of the original vehicle is greater than 950mm the length of the overhang of the
original vehicle is the maximum dimension. However for the rear diffuser defined in Art.3.4.3)
approved by JAF, its rear edge must be 950mm maximum from the center of ther rear wheel axle.
3.2) Windows
3.2.1) Front window
The front windshield must be in accordance with the rules under Article 9 of Chapter 4 Safety
regulations for homologated cars and registered vehicles. However it is permitted;
1) that a colorless transparent film is attached to the surface of the front windshield in order to protect
it.
2) that the material of the front windshield is changed into polycarbonate of which thickness is no less
than 6mm instead.
3.2.2) The other windows
1) The window glass may be replaced with some other transparent material which must permit the
cockpit interior to be visible, provided the same installation position, thickness, and shape as the
original glass are maintained.
2) Operational method and regulating system of the door window glass may be changed providing that
the original function of the door window glass is maintained. To the door of driver's side, door
window glass may not be fitted, however, it is obligatory to install protective nets defined under
Article 22 "Net" of the Chapter 4 Safety regulations for homologated cars and registered vehicles.
3) The window glass may have openings, however the total area of the openings must not exceed 15%
of the area of the each window concerned. There is no restriction on the shape of the ventilation
openings.
4) Air scoops may be installed to the outside surface of any window glass. Maximum protrusion of the
air scoop shall be 50mm measured perpendicularly from the outer window surface.
5) Following the removal of auxiliary accessories such as weather stripping and molding, it is
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permissible to install the window glass (except door window glass) directly to the vehicle bodywork.
6) The surface of the windows that are installed at the rear of the door windows on the lateral surface
of the car may protrude to the plane of extended surface of the door window glass.
7) A partition window may be replaced with a firewall.
8) When a tinted glass or a window film is used for side or rear windows, a driver inside the car must
be visible at a distance of 5 meters.
9) Windows situated to the rear of the door (of the front door for 4-door vehicle) and to the rear of the
rear bulkhead may be devitrified. If it is devitrified by painting, it must be clearly distinguished by
the contrastive color with the livery.
3.3）Bodywork
3.3.1) Changes in bodywork materials
Materials of the bodywork may be replaced by plastic materials or light metals provided that the
shape of the original vehicle (A pillar, roof, B/C pillar, window) is maintained.
However, if the bonnet (including engine-cover) and the rear hatch gate include glass component
and the glass material is changed, former part of glass component must be clearly distinguished by a
parting line. If the part is painted, it must be clearly distinguished by the contrastive color with the livery.
3.3.2) Door
1) For the door configuration, it is permitted that its area between the bottom surface of the flat bottom
and up to 120mm above it is removed, but the shape of the other part must be original. The back of
the door configuration may be altered.
2) The materials of the door can be changed into plastic materials or light metals provided that this
maintains sufficient strength of the structure.
3) Door hinge can be changed only for the purpose of giving the driver a quick escape from the car
during accident. If a door hinge is included in the part removed under 1) above, the relevant door
hinge may be changed.
For 4-door vehicle, four or more fasteners comply with 3.3.4) may be used instead of door hinges
and door locks when the function of opening/closing for rear doors is retained.
4) If the door mirrors are moved, original door mirror bases can be changed into plastic materials or
light metals.
5) For 4-door vehicle, rear doors may be widened in their width. The width shall be limited to the
extended outer surface of the rear fender. However the configuration of the car when viewed from
the side must be retained other than the part which is cut for forming wheel arch.
The function of opening/closing for rear doors is free.
3.3.3) Openings made in the bodywork
3.3.3.1) Openings in the bonnet (including engine-cover), rear hatch gate and boot-lid
1) They may be made to allow dissipation of heat and cooling provided the configurations of these
covers are not modified substantially. The openings are also allowed to be closed providing the
closed areas keep the original shapes or form outer enveloping surfaces.
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However the opening of the bonnet (including engine-cover) must fulfill the following conditions:
(1) It is situated 100mm forward of the rear edge of the bonnet (including engine-cover).
(2) The longitudinal length of the opening is 1,000mm maximum from the rear edge of the bonnet
(including engine-cover).
(3) The maximum width is up to 625mm to the right and left respectively from the longitudinal car
centerline.
the rear edge of
the bonnet
Parallel lines of the rear
edge of the bonnet
Drawing 1
2) They may be made in the rear hatch gate and boot-lid to allow dissipation of heat and cooling
provided the configurations of these are not modified substantially.
3) Opening accompanied by a change in hatch gate configuration may be made. However if it is made
within the extent of the original window, the change is limited within 15% of the original window
surface of the rear hatch gate and the total width of the opening is 400mm which must be symmetrical
to the longitudinal center line of the car.
4) Louvers, ribbing or lips etc. of which maximum protrusion up to 20mm may be installed and ducts
which are connected to the openings may be added. However when viewed from above these
openings must not permit the inside structure to be visible other than that of the duct connected to
an opening concerned.
3.3.3.2) Opening on fender
Cut-out (exit hole) may be created on the fender situated rear of the rearmost part of the complete
wheel to permit the escape of air used to cool the brakes. The inside must not be visible through this
exit hole when viewed from above and the side.
However, when an exit hole used to provide an exit for air already used to cool the brakes is situated
behind the rear wheels, except the part below the horizontal plane passing through the center of the rear
complete wheel, it must be covered either with a louver or with a very fine wire mesh in order to allow
nothing to exit other than air.
When opening is made on the fender for passing an exhaust pipe, the opening may have a gap up to
half of the diameter of the exhaust pipe.
3.3.3.3) Opening on ceiling
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One opening may be made on the ceiling providing the following conditions are respected:
1) It must be positioned no less 100mm behind of the rear edge of the front windshield. However if it
is made for introducing intake air to the rear engine, it must be situated behind the rearmost edge of
the rear bulkhead (air duct can be connected to the opening made on the ceiling).
Only if an intake duct is installed on the roof for engine as a standard equipment of the original vehicle,
it is permitted to take air for the engine from above the roof. However the shape of the duct may not
be altered from that of the original vehicle. Nonetheless for the competition car manufactured before
2015, it is permitted to take air for the engine from above the roof even if an intake duct is not
installed on the roof for engine as a standard equipment of the original vehicle.
2) Longitudinal length of the opening must not exceed the quarter of the ceiling's total length.
3) Its maximum width must be 400mm and symmetrical to the longitudinal centerline of the car.
4) It must not protrude from the surface of the car except air scoops which may be installed to the
outside surface of the bodywork, of which maximum protrusion shall be 40mm measured
perpendicularly from the outer surface.
5) When viewed from above, it must not permit the interior to be visible.
6) The structure inside the cockpit shall be no more than 150mm underneath the inside surface of the
ceiling and also be 100mm minimum above the driver's head.
3.3.3.4) Openings on the side of the bodywork when an engine is moved to the rear
In order to introduce outer air to cooll the bodywork parts, openings can be made for the rear doors
in case of 4-door vehicle, and on the body side panel at the rear part of the door in case of 2-door vehicle
providing the following conditions are respected:
1) (1) In case of 4-door:
It should be situated inside the peripheral parting line of the rear door and under the parallel plane
passing 770mm above the bottom plane of the flat bottom (The shaded portion of the Drawing 2).
(2) In case of 2-door:
It should be situated under the parallel plane passing 770mm above the bottom plane of the flat
bottom and in the area determined by the backward extended lines from the rear edge of the door
parting line and the lower parting line of the door and a plane perpendicular to the bottom plane of
the flat bottom passing the center of the rear wheel axle (The shaded portion of the Drawing 3).
2) After the introduced air passed the parts to be cooled it must be diffused and must not have any
aerodynamic effect.
3) It must not allow the inner part to be seen from the side and above.
4) Louver-shaped is prohibited and air scoop of maximum 50mm protrusion may be installed for the
opening. However the maximum width of the competition vehicle must not be exceeded as a result.
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770mm
Flat bottom
770mm
Drawing 2
Flat bottom
The backward extended lines from
the rear edge of the lower parting
line of the door
Drawing 3
3.3.3.5) Openings for the rear part of the bodywork
Openings situated at the rear of the bodywork must be covered with a very fine wire mesh or a
punching metal etc. .
3.3.4) Hinges of bonnet (including engine-cover), rear hatch gate and boot-lid
Hinges may be removed provided that the fasteners do not allow bonnet, rear hatch gate and bootlid to open during the vehicle in motion.
Where the engine or the fuel tanks are installed, these fasteners must be able to remove without tools.
The fasteners must be clearly indicated by a red (or contrastive color) arrow.
3.3.5) Bodywork (monocoque structure) and bulkhead
3.3.5.1) Bodywork (monocoque structure)
The monocoque and the rollcage approved by the JAF must be installed for the cockpit.
3.3.5.2) Front bulkhead (including cowl top)
1) The frontal panel of the monocoque installed under Art. 3.3.5.1) and panel installed between the
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monocoque and the cowl top may deemed to be the front bulkhed.
However, if the cowl top is removed the supporting structure for the lower edge of the front window
must be newly constructed.
The material and the shape of the cowl top cover are free. But it must not protrude from the perimeter
of the rear edge of the bonnet when viewed from the front.
2) Opening which is connected to the opening defined under Art.3.3.3.1) is permitted for the purpose
of ventilation of the cockpit provided the isolation function is maintained.
If the vent of the cockpit is connected to the duct installed at the back of the bonnet (including enginecover), the connected part must be of the structure which can prevent fire from intruding into the
cockpit when a fire in the engine compartment.
3) The shape and material of the front bulkhead, structure of connection of the openings defined under
Art.3.3.3.1) or a part which seals the openings existed originally:
Shape:
free
Material: (1) identical to that of the monocoque of the original vehicle and has equal or greater
thickness than that.
5) Openings may be made for the purpose of modifications permitted under Art.3.3.8)" Tunnel
installation to the floor part", 3.3.12.1) and by this provision, and for connecting the tubular structure
defined under Art.3.3.6) "Bodywork structure fore of the front bulkhead and hind of the rear
bulkhead "to the rollcage. However if it is necessary to create an opening its size must be minimal
for its purpose.
3.3.5.3) Rear bulkhead
1) New bulkhead may be installed after the rear bulkhead of the original vehicle is removed. In this
case the back panel of the monocoque installed under Art.3.3.5.1) may be deemed to be a part of the
rear bulkhead.
2) It is obligatory to install rear bulkhead which is positioned behind the driver’s seat when viewed
through from the side and can isolate the cockpit completely. However, minimum opening connected
to the opening according to Art.3.3.3.1)-3) for the ventilation of the cockpit is permissible on
condition that the cockpit’s isolation function is duly maintained.
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Area permitted for bulkhead installation
Drawing 4
3) The shape and material of the rear bulkhead, structure of the connection of the openings according
to Art.3.3.3.1-3) or a part which seals opening existed originally.
Shape: Free
Material: The bulkhead or the part must be made of a rigid and sufficiently fireproofing material.
3.3.5.4) Rear midship-engine vehicles
The followings are adopted for rear midship-engine vehicles in addition to the above 3.3.5.1)"Front
bulkhead" and 3.3.5.2)"Rear bulkhead":
The bulkhead separating the engine compartment from the luggage compartment and the floor part
of the engine compartment and the luggage compartment may be removed.
3.3.6) Bodywork structure fore of the front bulkhead and hind of the rear bulkhead
Main structure (structural framework) situated fore of the front bulkhead and/or hind of the rear
bulkhead may be cut and replaced by the tubular structure which is connected with the rollcage.
The material of the outer plane behind the rear bulkhead which serves also as a part of body structure
(monocoque structure) may be replaced by synthetic resin or light metals provided that substantial
strength and the shape, excluding permitted conditions defined under Art.3.3.3.3) "opening on ceiling",
are maintained . The plane may be removable only when it can be separated from each door, fender and
boot-lid. However, no play or gap between the part and the silhouette is permitted when seen from the
front, the rear and the side and it must be secured rigidly by hinges, a locking mechanism or the four or
more fasteners defined under Article 3.3.4).
When the main structure(structural framework) fore of the frond bulkhead is replaced by the
frame
structure connected with the monocoque, it is obligatory to install an impact absorbing structure ( a
crushable structure) defined under Article 12.5) "Frontal (back) protection structure" of the present
regulations.
A frame structure must conform to the following conditions:
1) Material: steel
2) Yield strength: endurable with 5.5W longitudinal, 1.5W lateral and 1.5W vertical loads (W=1,500kg)
(1) Parts to which the above loads are applied:
Front tubular structure: attachment points of the crushable structure
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Rear tubular structure: the rear edge of the tubular frame concerned
(2) Conditions when the above loads are applied:
(1) The floor part of cockpit (cabin) is fixed
(2) In running order (example; holes for the fixation of the suspensions are not closed. If an
engine, a gear box or a flat bottom etc. has a function as a stress member, it remains on that
part.)
(3) The following verification of withstanding against the obliged yield strength shall be
submitted to JAF:
(1) The result of the static load test, of the strength calculation (calculation report) or of the
analysis of the strength must be presented to JAF.
(2) Drawing of rollcage and tubular flame general construction and tube material &
dimensions.
It is not necessary to present the verification every year unless the vehicle type and its design
remain the same.
3) Method of fixation to rollcage
No processing or modification to the rollcage is permitted.
4) Even if the engine is dismounted, the parts which suspend the bodywork must work normally.
3.3.7) Flat bottom and floor
It is obligatory to install a flat bottom which complies with the following conditions. The flat bottom
must be installed across the total width of the car seen from its underneath without tire wheel housing
and outer mirrors.
1) A solid body that is rigid, flat and impervious plane under any circumstance, which covers the lower
surface of the car between the center line of the rotational axle of the front wheel and the center line
of the rotational axle of the rear wheel must be rigidly secured.
Materials are free.
Minimum width of the flat bottom is 950mm and it shall be symmetrical about the longitudinal
This plane may be composed of several pieces. However the gap of each piece between them
must be less than 1mm and the tolerance in vertical direction across the whole plane area is 5mm
maximum.
2) In any case, the flat bottom must not have an aerodynamic effect.
3) No air stream may pass between the floor of cockpit and the flat bottom except the parts fore of the
bulkhead, of passing the exhaust pipes(except side sill), center tunnel and tunnel for rear engine
vehicles.
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Bulkhead
Floor
Center line of the front wheel rotational axle
Flat bottom
Center line of the rear wheel rotational axle
Front edge of floor
Front edge of flat bottom
Rear edge of flat bottom
Drawing 5
4) Any suspended part of the car, regardless of the provisions under Art. 3.4.1) "Front aerodynamic
device" of the present regulations, must not situate below the plane formed by the flat bottom.
5) It is permitted to have radius of maximum 25mm upwardly at the periphery edge of the flat bottom.
6) Openings may be made into the flat bottom for the following reasons.
(2) Extraction of heat from the exhaust pipe ;
- The holes must follow the shape of exhaust pipe.
- Maximum diameter is 50mm
(3) Sensor use (Maximum diameter is 20mm)
However, for the purpose of passing the optical axis of the ride height sensor, it is permitted
to make maximum 4 holes (slits) of the dimensions of 20mm x 50mm (maximum).
7) Skid blocks approved by JAF must be attached to the front and the rear respectively. The skid block
must have thickness of minimum 8mm at no less than one part on the perimeter.
8) Provisions under Art. 3.3.12.1)- (3) "The shape of the tire housing" shall be satisfied.
3.3.8）Tunnel installation to the floor part
Tunnel installation for exhaust pipes
(1) One tunnel may be installed of which width up to 210mm and height up to 210mm provided it
does not affect the shape of the flat bottom toward the upper direction of the floor. However if a
car has an engine having banking on its RH and LH at the front, it is permitted to install one
tunnel for the RH and LH respectively.
(2) The processing to the surface of the bulkhead should be limited to a circumscribed square with a
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diameter up to 210mm.
3.3.9) Body side panel and side sill
3.3.9.1) Body side panel, side sill and floor
1) Body side panel, side sill and floor situated below the parting line at the lower part of the door window
may be newly installed after original body side panel, side sill and floor are removed.
2) Shape and material:
Shape: free
However outer surfaces of the body side panel and the side sill must be situated no more than 250mm
above the bottom surface of the flat bottom and between 120mm transversely inward from the lower
edges of the door outer surfaces. But modifications permitted under Art.3.3.8)-2) "Tunnel installation
for exhaust pipes" is permissible.
Material: rigid and sufficiently fireproofing material composed of the followings:
3) The structure which allows air to pass inside the side sill is prohibited.
4) To the lower part of the door between the front fender and the rear fender, side sill cover may be
installed following widening of outer surface of the original vehicle (door outer panel, outer surface
of the side sill or outer surface of side sill cover), however parts not widened must maintain identical
surface with the original vehicle.
The structure which allows air to pass between the outermost surface of this part and side sill is
prohibited. When an opening is made for the purpose of passing exhaust pipe on the outmost surface,
it should be limited to a circumscribed square with a diameter up to 120mm when viewed from the
side.
5) If the side sill cover is installed, its material is free.
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Door
Outer surface of body side panel & side sill
Side sill cover
Body side panel
& side sill
Lower edge of the door outer surface
Side skirt
Flat bottom
Drawing 6
Exhaust pipe tunnel
Door
Body side panel
& side sill
Side sill cover
MAX
Door lower edge
Exhaust
pipe
Side skirt
Flat bottom
MAX
Drawing 7
3.3.10) Bumpers
3.3.10.1.1) Front bumper
1) The shape of upper part which is divided by a horizontal plane passing 300mm above the flat bottom
base must be retained as original between the base points P1 and P2 of the Drawing 8. P1 and P2 are
the points where a straight line having 75% of the maximum width of the original vehicle which
intersect vertically with the longitudinal centerline of the car and symmetrical to it, contact with the
perimeter of the front bumper when viewed from above.
2) Between the base points P1 and P2 (Drawing 8) defined above 1), the bumper part situated more
than 40mm and 300mm or less above the bottom surface of the flat bottom may be modified
(including addition of opening) if the area falls inside the contour of the original bumper.
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3.3.10.1.2) Rear bumper
1) The shape of the upper part between the base points P3 and P4 on the Drawing 8 and aloft the
horizontal plane passing 300mm above the bottom surface of the flat bottom must be retained as
original. P3 and P4 are the points where a straight line having 80% of the maximum width of the
original vehicle which intersect vertically with the longitudinal centerline of the car and symmetrical
to it, contact with the perimeter of the rear bumper when viewed from above.
2) Modification(including cut) of bumper configuration situated lower than 300mm from the bottom
surface of the flat bottom may be permitted within the area determined by the rear axle center line
and the line parallel to it at the rear edge of the bodywork and the straight lines at an angle of 30°in
relation to the latter at the points laying 665mm from the longitudinal centerline of the car each side
and the lines parallel to the longitudinal centerline which contact with the outmost perimeter of the
bodywork (refer to Drawing 9). However horizontal surface must be maintained at the bottom of the
modified bumper within 650mm from the longitudinal centerline of the car each side.
Drawing 8
Center of rotational
axle of rear wheel
Longitudinal
center line of
car
Overall
width of
the car
Extended line from the base of
the flat bottom
Drawing 9
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3.3.10.2) Changes in bumper configuration accompanied by widening of fender width
These changes in bumper configuration are permitted subject to the following conditions only.
In order to facilitate examination of the configuration change, participants must carry a template with
them.
1) Permissible area for the changes of front bumper configuration
the car which contact with the outermost perimeter of the bodywork (refer to Drawing 8).
However, the front bumper situated within the area defined under the relevant regulations must not
be in the shape of canard or similar to it (ledge shape extended longitudinally).
2) Permissible area for the changes of rear bumper configuration
2)-1 Part above a parallel plane passing 300mm above the flat bottom base.
the car which contact with the outermost perimeter of the bodywork (refer to Drawing 8).
2)-2 Part under a parallel plane passing 300mm above the flat bottom base.
When seen from above, modification of the rear bumper in this area is permitted if it remains within
the area determined by the rear axle center line and the line parallel to it at the rear edge of the
bodywork and the straight lines at an angle of 30°in relation to the latter at the points laying 665mm
from the longitudinal centerline of the car each side and the lines parallel to the longitudinal
centerline which contact with the outmost perimeter of the bodywork (refer to Drawing 9).
3.3.11) Fenders
1) Fender may be widened up to 1,950mm within the overall width of a car. The front part of the front
fender and rear part of the rear fender must be fit within the area defined under Article 3.3.10.2)
"Changes in bumper configuration accompanied by widening of fender width "when seen from
above.
The rear edge of the front fenders must not extend over the parting line at the front edge of the doors
(the dimension of front fender may not be increased in longitudinal direction).
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Parting line at the front edge of the doors
Fender cannot be extended to the rear of
the line
Drawing 10
2) The design of the fender parts which are extended is free, however opening made must respect the
provisions of Art. 3.3.3.2) "Opening on fender" of the present regulations and have radius of 5mm
or more at projected parts having acute angles on the outer surface of a car, the fender parts which
are not extended must have identical surface with the original vehicle.
3) When the fenders of the original vehicle have openings for intake and cooling for the engine, it is
permitted that the dimensions of the openings are altered or the openings are closed as a result of
extension of the fenders. However it is obligatory to respect the provisions of Art. 3.3.3.2) "Opening
on fender" of the present regulations even in the former case.
4) Bumper and fender construction where the bumper extends into the inside of the fender are permitted
only if this is the original vehicle design.
5) Fender must not protrude beyond the perimeter of the upper edge of the fender of the original vehicle
viewed from the side. However if the tire housing installed in accordance with the prescriptions of
3.3.12)"Tire housing" interferes with the fender, the curved part which contacts with the installed
tire housing may protrude from the perimeter of the upper edge of the fender and the relevant
projected part may be connected with its circumference smoothly (by smooth radius).
Projecting part as a result of
construction of the tire housing
Smooth radius
Smooth radius
Parting line of the fender of the
original vehicle
Drawing 11
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6) If the original rear fender and rear pillar are of integral construction, the fender is considered to be
below the horizontal plane passing through the lower edge of the rear window.
3.3.12) Tire housing
3.3.12.1) In order to allow the tire housing to accommodate the front/rear complete wheel, an independent
tire housing which is formed by the planes inside of wheel arch must exist regardless of the structure of
the original vehicle. There are no restrictions on tire housing materials.
1) Tire housings must be installed within the area defined below, with the complete wheels in the straight
ahead position and the car in running order.
(1) Parallel to the bottom surface of the flat bottom, and above the plane passing through the wheel
center line: In the area within a radius of 410mm of the wheel rotational axle. The transverse
position (to the right and left of the car) is free.
(2) Parallel to the bottom surface of the flat bottom, and below the plane passing through the wheel
center line: In the area delimited by the planes passing the center of the rotational axle of the
right and left wheels and parallel to the plane perpendicular to the bottom surface of the flat
bottom, and within 410mm to the front and the rear respectively. The transverse position (to the
right and left of the car) is free.
(3) The shape of the tire housing
(1) The shape of the tire housing is free.
(2) The tire housing and the bodywork structure which are situated less than 50mm above the
bottom surface of the flat bottom in the area of the tire housing situated behind the frontal
edge of the flat bottom and in front of the rear edge of the flat bottom must be covered by
the flat bottom when seen from its underneath.
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Examples of the front tire housing
The angle
is free
Flat bottom
Flat bottom
Radius 25mm
Flat bottom
Examples of the rear tire housing
Rear tire housing
Rear tire housing
Flat bottom
Flat bottom
Rear tire housing
Radius 25mm
Rear tire housing
The angle
is free
Flat bottom
Flat bottom
Drawing 12
(4) Opening may be created on the aft part of the tire housing which is connected to the cut-out(exit
hole) permitting the escape of air used to cool the brakes created under Art.3.3.3.2) "Opening
on fender".
(5) Creating opening is permitted for the purpose of passing sprung parts, driving device and ducts
for cooling the brakes and of extracting heat from the exhaust pipe.
2) If the tire housing of the original vehicle was constructed already beyond the size defined by 1) above,
it must be within the dimensions of the original vehicle.
3) However where the front edge or the rear edge of the tire housing interfere with the bulkhead,
modifications may be made solely in the area within a radius of 460mm of the front wheel axle
rotational center with the wheels in the straight ahead position for the front bulkhead, and in the area
within a radius of 410mm of the rear wheel axle rotational center for the rear bulkhead.
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4) The side sill exists within the area defined by 3) above may be removed.
3.3.13) Side skirts
Side skirts are permitted on condition that, and there are no restrictions on side skirts materials.
1) it is installed below the horizontal plane passing through the center of the front and rear wheel
rotational axles of the car in running order.
2) within the area (width) extended by the maximum vehicle width.
3) The front/rear edge and the lateral edges must have a radius of more than 5mm.
4) The outer surface of the side skirts may not enter the inside of the outer surface of the original vehicle.
5) Furthermore it must be connected to the flat bottom without any gap and also to the front/rear fenders.
3.3.14) Engine compartment
3.3.14.1) Radiator support and its supporting members may be removed.
3.3.14.2) Bonnet (including engine-cover), rear hatch gate and boot-lid
If the tire housing installed in accordance with the prescriptions of 3.3.12)"Tire housing" interferes
with the bonnet (including engine-cover), rear hatch gate or boot-lid , the relevant part which contacts
with the installed tire housing may protrude in a curved shape follows the upper edge of the tire housing.
The relevant projected part may be connected with its circumference and the fender smoothly (by
smooth radius).
3.3.15) Luggage compartment
The floor of the luggage compartment may be removed but the ground must not be seen with the
rear aerodynamic device under the floor is fitted except the tire housing and openings permitted in this
Section.
Flat bottom
Drawing 13
1) In the space situated above the rear aerodynamic part under the floor, only the air passed through
heat exchanger may flow. If the air flows (in the space) over the lowest surface of the bodywork
(floor surface of the luggage compartment) and the purpose of that opening is the escape of air which
passes through radiator installed inside the luggage compartment etc., the cross section of the
opening must be less than the area of the radiator core.
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2) When the floor of the luggage compartment is removed;
(1) It is permitted install a crushable structure in order that the influence resulted from these changes
against impact must be minimal.
(2) In order to provide greater rigidity for the bodywork, cross-members can be freely added.
3.3.16) Hard top for open cars
Provided the following conditions are observed, hard top for open car may be installed.
1) Configuration: If the original open car has a soft top or a hard top as its optional parts, the hard top
which may be installed must maintain its configuration similar to the original.
2) Material: rigid and sufficiently fireproofing material and must be either of the followings, except the
attachments (including flanges);
(2) Carbon fiber material having honeycomb construction no less than 10mm thickness
3) The highest point: The highest point indicated in the 3- view-drawing of the catalogue of the vehicle
concerned should be regarded as the highest point of the car.
4) Fixation: There is no restriction on its fixation method. However fixing to homologated rollcages
may be authorized only if there is no need to carry out any modification to the rollcages.
3.3.17) Vehicle interior
Removal and new installation of the dashboard (instrument panel) are permitted. But it must be so
constructed that any components in the cockpit does not scatter and it does not hit the driver in case of
impact.
Flexible air ducts made of non flammable material may be installed to the vehicle interior for the
purpose of cooling the driver and various auxiliary equipment(electrical equipment). It is also authorized
that the flexible ducts are connected with air scoops specified in Article3.3.19) "Auxiliary accessories"
of the present regulations, however it must not obstruct driver's visibility.
Oil tank installation to the vehicle interior (cockpit) is not permitted.
3.3.18) Reinforcement
Reinforcement of the bodywork (including bulkhead) is free provided it does not encroach on the
spaces inclusive of driver's and passenger's compartments. However any modification or processing to
the monocoque and rollcage may be carried out only if JAF authorize it.
3.3.19) Auxiliary accessories
Demisting devices and cockpit ventilation systems are free provided that the original ventilation
openings are remained and the outside shape is not significantly changed (Maximum protrusion 20mm).
3.4) Aerodynamic device
3.4.1) Front aerodynamic device
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(1) It is obligatory to use the front under panel apporoved by JAF.
(2) Modification may be carried out within the following extent on condition that the under panel
apporoved by JAF is used.
(3) Members necessary to reinforce the jointing of the front bumper and /or the fixing of the front under
panel may be added in the area situated inside the front bumper with the car in running order.
However for the under panel approved by JAF any machining is not permitted and only bonding
(and sanding for bond) is permitted.
Front
edge of
the flat
bottom
Front wheel axle
centerline
Overall
width of
the car
Flat bottom
Front aerodynamic device
Height limitation at front
and rear edges
Drawing 14
(4) Materials of the members bonded are free.
(5) Flap (canard) may be installed in the area (Drawing 15);
(i)
below the horizontal plane passing 250mm above the bottom surface of the flat bottom of the
car;
(ii) forward of the front complete wheel and outside of the points P1 and P2 ;
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(iii) inside the parallel line max. 950mm forward of the line connecting the axle centers of right
and left front wheel and the straight lines at an angle of 30°in relation to the fore-mentioned
parallel line at the points laying 460mm from the longitudinal centerline of the car and the
lines parallel to the longitudinal centerline which contact with the outmost perimeter of the
bodywork.
(iv) be 120mm or less from the perimeter of the bodywork.
(v) Shape is free provided that it is not situated outermost perimeter of the bodywork.
The longitudinal
centerline of the car
Overall width
75% of the
original car
Front
wheel axle
centerline
Overall
width of
the car
point Point P2 at
the opposite side
Section
Max.
Canard
Flat bottom
Max.
Drawing 15
3.4.2) Rear aerodynamic device
As a rear aerodynamic device, either a rear air spoiler or a rear wing may be installed provided the
followings are observed:
1) Number of the device should be one unit.
2) The wing should be one and any part of the aerofoil section should be able to fit in a 400mm×150mm
rectangle (including gurney-flaps, excluding supports and end plates).
3) Its height should be limited by the top of the ceiling except optional parts(1,100mm above the bottom
surface of the flat bottom).
4) The maximum width is 1,900mm (including supports and end plates).
The area determined by the line parallel to the rear axle center line at the rear edge of the bodywork
and the straight lines at an angle of 30°in relation to the line at the points laying 665mm from the
longitudinal centerline of the car each side and the lines parallel to the longitudinal centerline which
contact with the outmost perimeter of the bodywork
(refer to Drawing 16) is to be regarded as the
outermost edge of the perimeter of bodywork, and the above mentioned rear device may be installed
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within this extent.
Rear wheel axle
centerline
Rear wing
Drawing 16
5) It should be placed above the perimeter of the bodywork and the parting line of the rear fender when
viewed from the side, or on the surface of the boot-lid (engine-cover).
(It is not permitted to install any aerodynamic device onto the rear fender.)
6) It should be situated behind a plane vertical to the bottom surface of the flat bottom and passing
through the center of the rear wheel rotational axle.
7) The frontal edge and the lateral edges including end plates should have a radius of no less than 5mm.
8) The shape and materials are free. When installing the device to the boot-lid, it is permissible to install
reinforcements to the inside of the boot-lid to provide greater rigidity for the fixation of supports.
9) The boot-lid and rear hatch gate should be able to be opened and closed without removing any
structural part.
3.4.3) Aerodynamic devices beneath the rear floor
1) It is obligatory to use the rear diffuser approved by JAF.
2) Modification may be carried out within the following extent on condition that the rear diffuser
approved by JAF is used.
3) Bodywork part may be added only in the area situated above the inclined panel however for the rear
diffuser approved by JAF any machining is not permitted and only bonding (and sanding for bond)
is permitted.
4) Vertical fins may be installed under the following conditions, Materials are free:
(1) They remain parallel to the longitudinal center-line of the car.
(2) They exert no aerodynamic influence.
(3) Maximum 4 fins
(4) Holes that are already made on the rear diffuser approved by JAF may only be used for the fixing
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positions.
The ground must not be seen when a
boot-lid(trunk) or a hatch gate is opened
bodywork structure
Space
Inclined panel
Vertical fin
bodywork structure
Bracket to install vertical fin extended
from the inclined panel to the rear
Circle of the
diameter of
50mm
Inclined panel
Vertical fin
bodywork structure
Inclined panel
Vertical fin
Drawing 18
5) Openings may be made into the inclined panel for the following reasons:
(2) Extraction of heat from the exhaust pipe.
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- The holes must follow the shape of exhaust pipe
- Maximum diameter is 50mm.
(3) Sensor use
Maximum two holes of which diameter is up to 20mm x 50mm may be created.
(4) Breather hose use
Article 4: Weight
4.1) Minimum weight
Minimum weight must be respected as laid out in the Appendix 2 of this Section. The JAF may
change the minimum weight requirements with notice in advance at any time during the season in order
to provide equality of performance.
4.2) Ballast
It is permissible to install one or more ballast to fulfill the requirement of the minimum weight. The
position and the installation method of the ballast are free, but both the ballast and the bodywork part to
which the ballast is fixed must have sufficient strength.
Article 5: Engine
5.1) Type of engine
Only engine approved by the JAF may be used.
5.2) Position of engine
The mounting position of the engine may not be altered from that of the original vehicle. The position,
location and orientation of the engine in the original engine compartment are free.
5.3) Engine modifications
The engine approved by the JAF must remain as it was supplied.
5.5) Lubricating system
When viewed from above, the oil cooler must not protrude from the vehicle perimeter. If the oil
cooler is installed outside the vehicle, it must be positioned below the horizontal plane passing through
the wheel rotational center of the vehicle in running order.
5.5) Air intake system
Free other than the parts originally fitted to the engine approved by the JAF.
5.5.1) Air restrictor
All cars must have either 1 or 2 air restrictor(s) made of metal with a tube(s) having circular section(s)
maintained for a minimum length of 3mm. All air admitted to the engine must pass through the air
restrictor(s). When all the intake air is forced to stop upstream of the air restrictor(s), engine must be
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immediately stopped.
5.5.2) Air restrictor diameter
Air restrictor diameter must be maintained as specified in the Appendix 2 of this Section. Air
restrictor diameter must comply with the prescribed value at all time during an event.
The JAF may change the air restrictor diameter requirements with notice in advance at any time
during the season in order to provide equality of performance.
5.5.3) Air box
It is obligatory to equip an air box and the air restrictor must be installed to an air inlet of the box.
The air box must satisfy the following conditions:
1) It must not exceed 1,000mm x 500m m x 500mm
2) Intake ducts in front of air box are free provided the external appearance of the car is not changed.
The internal structure and also the material of the air box are free.
3) When all the intake air is forced to stop while the engine is running, the engine must stop and the
air box and those intake ducts in front of it must have sufficient rigidity not to be damaged or
failed.
5.6) Cooling
Water radiators are free, as long as its function is identical to the one installed to the original vehicle.
For the purpose of cooling the water radiator, oil cooler and each engine part, only air is permitted
and other cooling method by injection or spraying of any substance other than air into them is prohibited.
Heat exchanger can be used.
Flexible air ducts may be installed in the engine compartment to cool auxiliary equipment of the
engine.
5.7) Exhaust system
The exhaust system is free. However,
1) at least one catalytic unit must be installed through which all exhaust gases should pass. The unit
must be approved by JAF and the application must be submitted no later than 2 months before the
competition in which the unit is used for the first time;
2) variable exhaust systems are not permitted.
Exit of the exhaust should be as follows for the cars with a lateral exhaust exit:
1) Minimum height: the lowest point of the exit must retain the minimum ground clearance without fail.
2) Maximum height: the highest point of the exit must not exceed the parallel plane passing 300mm
Article 6: Lines and pumps, and fuel tanks
Free as long as Articles 6.1), 6.2) and 6.3) are observed.
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6.1) Fuel tanks
Only the safety fuel tank approved by the JAF may be used.
It is obligatory that a flexible joint be used for the junction of the fuel tank and fuel filler neck, which
can allow bodywork deformation in some degree and avoid any leakage of fuel.
6.1.1) Location of Fuel Tanks
All safety fuel tanks must be situated in the designated positions in the monocoque that are approved
by the JAF.
Leakage of the fuel must not be accumulated and careful attention should be paid for it so as not to
go into the cockpit.
6.1.2) The use of self sealing breakaway valve for all fuel lines between the fuel tank and the engine is
considered desirable. This valve must operate at less than 50% of the load required to break the fuel line
fitting or to pull it out of the fuel tank.
6.1.3) Fuel supply system
It must not be installed in the cockpit and outside of the bodywork. Except for the fore-mentioned
condition, the system is free.
6.1.4) Unless the tank fillers are connected directly to the tank, it is recommended that a valve supplied by
the tank manufacturer be installed at the top of the tank. The valve should permit sealing the fuel tank
in the event of the filler being knocked off during an accident.
6.1.5) Position of the filler
1) Minimum height: The center of the filler must not be lower than the plane passing through 595mm
2) The distance between the center of the filler and the edge of the exhaust exit must be 1000mm or
more in plain view.
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the center of the filler
Flat bottom
Exhaust
exit
Filler
Drawing 20
6.2) Fuel capacity
The maximum amount of fuel which may be carried on board is 100 liters.
The JAF may reduce the total fuel tank capacity with notice in advance.
6.3) Number of fuel cllector tanks
The number of the collector tank is limited to one.
6.4) Cooling of fuel
It is permissible to install cooling device to the fuel supply piping mounted on the vehicle for the
purpose of decreasing the temperature of fuel. The only method allowed for cooling fuel is air-cooled
method by natural air stream.
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Article 7: Electrical Equipment
7.1) Battery
Only sealed batteries are permitted. Insulation to prevent shorting must be installed.
The battery may be mounted anywhere except in the area of the driver's seat.
There are no restrictions on battery make and capacity.
7.2) Lighting
Indicators, by which the driver may recognize whether the headlight and/or the direction, must be
fitted.
7.2.1) Headlights
1) Headlights must remain in their original position. Their configuration and function of the original
vehicle must be maintained. The main optical axis must be to the front. Brightness (light intensity)
must be at least equal to that of the original vehicle's headlights so that the lightening can be
recognized by the drivers of the cars running in font and the officials around the track. Right and left
lights must not be illuminated by turns.
2) Headlights must have yellow or amber colored covers.
3) It is authorized to alter a light source for the purpose of increasing illumination (or luminous
intensity).
4) If the vehicle is originally equipped with retractable headlights, the retracting mechanism may be
removed and modifications with transparent materials may be carried out so as to lighten the front
of the vehicle.
7.2.2) Other lights
7.2.2.1) Tail light and brake light
Tail light and brake light must have the same configuration as those of the original vehicle.
Brightness (light intensity) of these lights must be equal to or greater than that of the original lights.
7.2.2.2) Direction indicators
The lightening of indicators must be recognized by the drivers of the cars running in front/behind
and the officials around the track. The diameter of the indicators' lens surface is required to be at least
30mm.
There is no restriction on side markers including its removal.
7.2.2.3) Rain light
One of the following rain lights defined below must be fitted to the rear of the car which is in working
order throughout of an event.
(1) Rain light that is approved in accordance with ECE R38 road standard (or an equivalent or stricter
standards from another country).
(2) One rain light approved by the FIA ( Technical List No.19).
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(3) Rain light which has an equivalent brightness as (2) above and comply with the following rules:
- The surface of the lens that is visible from the rear of the car is 30 ㎠ minimum and 140 ㎠
maximum.
- Luminous intensity is no less than 150cd and no greater than 300cd.
- Luminescent color is red only.
The rain light must fulfill the following conditions:
- Emission pattern of the light is solid only.
- Independent circuit should be secured for the light apart from the other optical circuit.
- It shall be perpendicular to the centerline of the car and faced toward the rear of the car.
- It should be clearly visible from the rear.
- It should be installed within 10cm from the centerline of the car.
- It should be at least 35cm above the bottom surface of the flat bottom.
- The surface of the lens should be at least 45cm behind the centerline of the rear wheels when
measured parallel with the bottom surface of the flat bottom.
- It should be able to be switched on by the driver when seated normally in the car.
The three measurements are taken to the center of area of the lens.
7.2.2.4) Other lights
Ducts can be connected to openings which are created by removal of the original lights.
7.2.3) Wiper
It is permissible to change the front window wiper construction. However at least one wiper must be
equipped and it must be able to be operated by the driver seated and activated effectively at any time
during an event.
Article 8: Transmission
8.1) Drive system
Changes in drive system are permitted regardless of the system used in the original vehicle.
8.2) Clutch
8.3) Transmission and transmission control lever
The gearbox must comprise a maximum of 6 ratios and a reverse gear. Mounting position is free.
Use of a paddle sift system is authorized.
8.4) Final drive system and differential
The viscous clutch is permitted provided that it is not controllable when the car is in motion.
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8.5) Propeller shaft and drive shaft
Free.
8.6) Cooling
Only air cooling of the transmission is permitted. Injection or spraying of any substance other than
air to cool the brakes is prohibited.
Mounting of oil cooler is free provided it is not exposed outside the car.
Article 9: Suspension and steering
9.1) Suspension type and installation
Suspension type on the original vehicle may be freely modified and altered.
However, even if the suspension fixation point on bodywork side is changed, the suspension must
work normally when the engine is dismounted.
9.2) Anti-rollbar
There are no restrictions on anti-rollbar including their installation brackets.
Adjustment of anti-rollbar can be made mechanically only by driver when the car is in motion. This
must not be adjustable by any other means than the said method.
9.3) Axles
There are no restrictions on axles including spindles. They may be changed into Center locking type.
9.4) Springs
There are no restrictions on springs including the addition of supplementary springs provided the
conditions set out in the Article 2.1.2) "Control function restrictions" are respected.
9.5) Shock absorbers
There are no restrictions on shock absorbers provided the conditions set out in the Article 2.1.2)
"Control function restrictions" are respected.
9.6) Suspension arms
All suspension arms must be made of metal.
9.7) Chromium plating
Chromium plating of steel suspension arms is not permitted.
9.8) Steering
Steering wheel, steering system (steering gearbox, link) and steering wheel must be connected solely
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by mechanical means.
Power steering is permitted to use only if it is a single system without a programmable control.
The shape of the steering wheel is free. It must equip a quick release system including a flange
concentric to the steering wheel axis installed on the steering column. The release must be operated by
pulling the flange along the steering wheel axis
It is recommended to install a steering column with an impact absorbing device.
Article 10: Brakes
10.1) Brake system
The brake system is free, provided the conditions set out in the Article 2.1.2) "Control function
restrictions" are respected.
However, there must be no sensors or devises other than a fluid pressure sensor, a brake light switch,
a proportional brake valve and ABS hydraulic pressure unit approved by the JAF on the lines between
master cylinder and caliper.
Parking brake installation is optional.
10.2) Brake calipers
A single caliper is allowed for each wheel. Each caliper may have up to 6 pistons. The cross-section
of each piston must be cylindrical.
10.3) Brake cooling
Only air cooling of the brakes is permitted. Injection or spraying of any substance to cool the brakes
is prohibited. However, the use of brake caliper cooling system by a liquid circulation is permitted.
Air ducts for cooling the brakes may be installed in accordance with Art.3.3.3.4) and 3.3.10.1.1).
However, these ducts must not change the bodywork configuration above the bumper and not permit
the aerodynamic effect beneath the vehicle between the front and rear wheel center lines (within the
wheelbase).
There is no restriction on the number and size of air ducts used to cool each brake assembly.
Materials of the air ducts are free.
10.4) Brake discs
Maximum one brake disc made of ferrous material per wheel is permitted.
Article 11: Wheels and tires
11.1) Dimensions
11.1.1) Complete wheel maximum diameter and maximum width
Maximum diameter: 28 inches
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Maximum width: 14 inches
If the maximum width of the complete wheel exceeds 12 inches the following conditions must
be met:
1) Only material may be used is aluminum.
2) The minimum weight is 10kg/wheel, however it includes air valve and excludes balance weight.
11.2) Wheel material
Wheel material is aluminum only and the minimum weight of one wheel is 10kg. However balance
weight including air valve is not included in the weight calculation.
Accessories of wheels are permissible only if they do not exceed the maximum width of the complete
wheel and are secured by bolts etc.
11.3) Wheel attachment
Wheel attachment is free, if a single center nut, a red or dayglo orange safety spring or a
device/system performing the same function as the said spring must be installed to each wheel when the
car is in motion. The safety spring or the similar device mentioned above must be installed after each
wheel change.
11.4) Pneumatic jack
Pneumatic jack installation is permitted. However, the installation of a compressed air bottles to the
vehicle is prohibited.
Article 12: Safety equipments and devices
All the regulations concerning safety are completed by adding the following to the Chapter 4 "Safety
regulations for homologated cars and registered vehicles" and applied.
12.1) Safety belts
The wearing of two shoulder straps, one abdominal strap and two straps between the legs is
compulsory.
Safety belts must comply with FIA standards 8853/98.
Each strap of the safety belt must have its own fixation point on the bodywork. Two abdominal straps
for right and left respectively can be prepared as long as they have the same homologation numbers and
the two abdominal straps on one side may be attached together by one attachment point on the body.
12.2) Rear view mirrors
It is permitted to remove an inside mirror or replace it with any other system of equivalent efficiency,
when the bulkhead extends from the floor to the ceiling under the prescriptions mentioned in 6.1.1), or
when a partition window serves as a bulkhead as defined under the Art.17 "Protection against fire" of
the Chapter 4 "Safety regulations for homologated cars and registered vehicles", regardless of the
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provisions under Art.7 "Rear view" of the Chapter 4 "Safety regulations for homologated cars and
registered vehicles". However, in this case, the rear view must be secured, and outside mirrors of the
original vehicle or having no less than 100 ㎠ must be mounted on the both side of the outer surface of
the bodywork.
12.3) Seats and Headrest
It is obligatory that FIA homologated competition seats (Standards 8855-1999 or 8862-2009) which
have a reinforcement part around the driver’s head padded with energy absorbing and non flammable
material be used.
The driver's seat can be moved towards the center of the car unless it does not go beyond the
longitudinal center line of the car.
Headrest must be able to retain the driver's head wearing a helmet and must not have it move
rearward during acceleration. The driver’s head must not be caught between the headrest and rollover
bars. It is recommended that the distance between the sides of the headrest should not exceed 400mm
and that energy absorbing material of minimum 20mm is fixed to the both sides.
12.4) Relation between seats, rollcage and lateral protection structure
The following dimensions should be respected within the plane perpendicular to the centerline of a
car and to the surface of the flat bottom including the lowest point of the seat at the center of it.(Drawing
21) However when the seat has a sliding system, the position of slide can be optional.
1) The distance between the center of the seat and lateral roll bar should be 950mm or more.
2) Between the center of seat and the lateral protection structure, horizontal distance should not be less
than 250mm and the difference of their vertical height should not be greater than 430mm.
Cross section of lateral roll bar
The lowest point
of the seat at the
seat’s center
The lowest point of the
seat at the seat’s center
Aria for lateral
protection structure
Flat bottom
Side view of a car
Drawing 21
12.5) Relation between driver’s helmet and roll cage
When a driver is seated in his normal driving position and looks straight ahead, roll cage must not
be existed within the range shown in the Drawing 22 when seen from the side.
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Line contacts with the highest point the
ahead and parallel to the flat bottom
Line contacts with the rearmost point the
ahead and perpendicular to the flat bottom
Rollcage can not be
exited within the
meshed part
Side view of a car
Flat bottom
Drawing 22
12.6) Elements between the door and the driver's seat
Between the door and the driver's seat, no mechanical components may be installed other than side
bars of the rollcage.
However, the impact absorbing structure, the knee pad and the water-supply bottles are not
considered as mechanical components.
12.7) Frontal (back) protection structure
Impact absorbing structure approved by the JAF must be installed.
1) The structure mounting position
Forward of the frontal frame structure. Mounting the structure to the rear part of the frame is not
obligatory (optional).
2) Impact resistance
The average deceleration of the car must be less than 25G and must not exceed the maximum
deceleration 60G for more than 3ms when a frontal impact test is carried out.
For this test the car's
weight must be 1,500kg. The car shall collide head-on (full overlap) by at a velocity of 12metre/sec.
3) Dynamic crash test
A unit of crushable structure on a trolley is subjected to a dynamic crash test. A certification with a
signature of the person in charge of the testing laboratory must be issued and its copy must be
submitted to JAF.
4) Impact absorbing structure may be installed between the door on the driver's side and the rollcage.
12.8) Cockpit exit time
When the driver escapes from the cockpit in an emergency from his normal driving position, the
structure must allow the driver to get out of the car within 7 seconds from the door of the driver's side
and 9 seconds from the door of the passenger's side.
12.9) Extinguishing equipment
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Installation of the automatic extinguishing equipment defined by Art.253.7.2 of the Appendix J is
compulsory.
Article 13: Other requirements
13.1) Guards and Supports
Installation of radiator guard, tank guard and sump guard is permitted. However the prescriptions
defined under the Article 3.3.6)"Bodywork structure fore of the front bulkhead and hind of the rear
bulkhead" must be satisfied.
Other than magnesium, there is no restriction on materials.
13.2) Handicap weight installation devices
In order to enable the handicap ballast to be installed, weight installation device (rigid construction)
must be equipped at the place where scrutineers of the event concerned can easily check it.
Article 14: Final Text
The final text for these regulations shall be the Japanese version should any dispute arise over their
interpretation.
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Appendix 1
Article 2 2.1.2) Examples of prohibited systems according to the restrictions
on control functions
Prohibited system etc.
1
Automatic gearbox
2
Power actuated clutch
3
4
Electronically or automatically adjusted final drive differential system (ex.: Differentials with
air pressurizing or hydraulic slip control with electronic control and / or outer pump)
Electronically or automatically adjusted shock absorber, suspension or ride height adjustment
5
Four-wheel steering
6
Moveable ballast
7
Electronic control systems with closed-loop circuit other than engine
8
9
Devices that allow a driver to adjust shock absorber and suspension springs from the driver's
seat when the car is in motion
Telemetry
10
Active suspension
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Appendix 2 : Minimum vehicle weight and air restrictors
Cubic
Capacity Div.
（cc）
<=2,000cc
2,000cc<
<=2,500cc
2,500cc<
<=3,000cc
3,000cc<
<=3,500cc
3,500cc<
<=4,000cc
4,000cc<
<=4,500cc
4,500cc<
<=5,000cc
5,000cc<
<=5,500cc
No.
（mm）
Min. weight Div. （kg）
1,100
1,150
1,200
Installation Exemption
1
42.90
43.77
44.66
2
30.66
31.28
31.91
1
41.43
42.28
43.13
2
29.61
30.21
30.82
1
40.49
41.31
42.15
2
28.98
29.57
30.17
1
39.86
40.67
41.50
2
28.46
29.04
29.63
1
39.45
40.25
41.06
2
28.15
28.72
29.30
1
39.03
39.82
40.63
2
27.83
28.40
28.97
1
38.71
39.50
40.30
2
27.62
28.18
28.76
1
38.30
39.07
39.87
5,500cc<
2
27.31
27.86
28.43
* For Supercharged engine the capacity will be multiplied by the 1.7
coefficient and the section corresponds to the result in the table will
be applied.
***
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2016 JAF Grand Touring Car 300(JAF

Transcription

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