World ofrally - The Chelsea Magazine Company

Transcription

The leading motorsport technology publication since 1990
Special digital edition • July 2016 • www.racecar-engineering.com
World of rally
E [email protected]
CONTENTS
Contents
4 HYUNDAI
i20 R5 under the spotlights
12 PEUGEOT 2008 DKR
Rally raid Dakar winner
18 ABARTH
Lightweight rallying
20 DANNY
Slip angles on gravel
26 RALLY 2017
What’s that coming over the hill?
Produced by Andrew Cotton, Sam Collins,
Mike Breslin and Dave Oswald
RALLY 2016 DIGITAL SPECIAL 3
R5 - HYUNDAI I20
4 RALLY 2016 DIGITAL SPECIAL
Hy’ Five
Hyundai’s i20 R5 is the latest in
a string of customer sport rally
cars to roll out of manufacturers’
workshops. But will it be able take
the fight to M-Sport and Skoda
out on the stages?
By MARTIN SHARP
The Hyundai i20 R5 in full flow during the Ypres
Rally ERC round in June, where it ran as a course
car. Like all R5 cars the i20 is powered by a
1.6-litre production based engine, it is four-wheeldrive, and is cost capped at 180,000
T
he FIA’s car and component cost-capped R5
regulations define competition cars which
may appear ostensibly similar to World
Rally Cars, but these machines are in fact
one tier down from the WRC top level. They do have
a similar powertrain layout to the current WRCs, with
passive front and rear differentials and no centre diff
in their four-wheel-drive system. They can also have
a turbocharged engine up to 1620cc, but this must
be based on a manufacturer’s production engine –
hence WRC-style ‘Global’ engines are not allowed. The
turbocharger must also be from a production car, while
just five forward gear ratios are allowed with one final
drive ratio. Suspension must be MacPherson strut, and
all four uprights must be identical.
Beyond these headline points, the R5 regulations
are actually quite complex, incorporating maximum
prices for components and assemblies, aimed at
producing a highest price of €180,000 for a new asphalt
specification R5 car before tax and registration costs –
although FIA Appendix J still allows for free options in
the areas of seats, batteries and the like.
The R5 category has proven itself in leaps and
bounds since M-Sport’s Fiesta became the first R5 car to
hit the stages in 2013. This was some six months before
the – delayed, and troubled – arrivals of its first rivals:
PSA’s Peugeot 208T16 R5 and Citroen DS R5, both of
which were developed by Peugeot Sport. Also, while
M-Sport was working flat-out three years ago to bring
its Fiesta R5 first to the rallying party, Skoda Motorsport
had already begun its Fabia R5 project, too.
R5’s arrived
R5 is now firmly established as the top formula for
national, regional and WRC2 rallying. With the effective
demise of Regional Rally Cars (essentially more
stringently inlet-restricted WRC cars) WRC2 is now
dominated by R5 cars, as are national and regional rally
championships across the rallying world.
The Fabia R5 was not homologated until April
2015, scoring its first fastest stage time on last year’s
Ypres Rally. This demonstrated the Czech team had
not wasted the Fabia R5’s lengthy gestation and that
rival R5 teams needed to up their game. M-Sport met
the challenge head-on with much improved power,
torque output and characteristics in the Fiesta R5 Evo
(also seen on entry lists as R5+), and Peugeot Sport has
planned upgrades to its pair of PSA R5 cars to close the
gap to the top-running Skoda and M-Sport Ford.
Now, in the latter part of this year, privateer and
semi-privateer teams wishing to compete in R5 have
another, fresh, alternative: Hyundai Motorsport’s New
Generation i20 is getting the R5 treatment. But this new
Korea-derived R5 car, designed and developed out of
Hyundai Motorsport’s base in Alzenau, Germany, will
only be homologated when everything is right. ‘We
are still in a phase of development and testing and we
don’t really want to rush if the car is not ready, because
its basic design is even more critical than a World Rally
Car,’ says Michel Nandan, Hyundai Motorsport team
principal – referring here to the complex and restrictive
nature of the R5 rules, as mentioned above.
‘This is because you have to get it right at the
beginning. There’s not a lot of jokers, first; which is also
not good for the customer, so we have to provide a
R5 - HYUNDAI I20
Hyundai Motorsport has been allowed to use the roll cage and the bodyshell from the existing 2016 i20 World Rally Car for the R5, but the rest of the car is completely different from its WRC sister
car which is reliable enough, which has been
tested on the different surfaces and different
conditions that people will use it in, and to
give all the base set-ups to the people,’ Nandan
says. ‘So we really don’t want to rush it too
much, but it’s planned to homologate this
car during the summer some time. We will
decide, I think, really at the last minute when
it will be: if it will be, let’s say, in July or August
[this year], but the plan is like this. We’re still
continuing our process of development and
also durability tests and everything.’
All top rally cars have to be right at
the beginning of their lives, of course, but
Nandan’s statement is prescient and rally
engineers involved in R5 agree generally
that the design stage of an R5 is crucial, and
arguably more difficult, than that of a WRC.
‘In fact, I have to tell you, that is true,’ says
Nandan. ‘With the regulation we have at
the moment it’s a car which we can name
as a compromise car. This type of car is a
big compromise because you have to cope
with the rules … And I have to say it’s not so
easy to make a competitive car with all the
compromises you have to make. So, I think
it’s not an easy job,’ he adds.
Hyundai Motorsport’s R5 programme is the
first initiative to derive from its new Customer
Racing department, which was approved
by the Korean headquarters in the middle
of last year, and established in September.
The company recognised that R5 is a top
category in all national rally championships,
and concluded it is important for Hyundai to
have cars fighting in championships all over
the world. Nandan says: ‘It was a very good
decision to be allowed to do such a car.’
R2 me too
As the customer department grows, its next
project will be an R2 car, but currently the
newly formed group is establishing itself and
concentrating wholeheartedly on the i20 R5.
In the early design stage of the second-tier
i20 rally car Korean engineers were brought
in to assist, partly because of the implied and
regulated requirement to incorporate more
standard components in an R5 than in a
World Rally Car. And indeed, Hyundai
Motorsport engineers involved with the
WRC programme also diverted their talents
toward the R5 car. Because of the costconscious nature of the rules, negotiations
with suppliers had to become more intense,
necessitating an increased head count in the
team’s purchasing department.
Nandan explains: ‘The aim of Hyundai
Motorsport was to use all the different
department structures we have in order to
R5 regulations are quite complex, incorporating
maximum prices for components and assemblies
share the people and the departments. But
it’s true that for some aspects, of course,
you need more people; for example in the
customer department you need to have other
people dedicated. So, we use some of the
people from, let’s say, the workshop or subassembly or things like that, and then people
are working together on WRC and R5. But
then with some other aspects of the customer
department, and also all the R5 engineering
support, there will be dedicated people only
involved in this customer business.
‘It’s a mix of everything, but it is done
in a way to use the efficiency of Hyundai
Motorsport and the departments which are
already in place, plus the equipment, in order
to – first to save a bit of money, of course –
but also to be more efficient,’ Nandan says.
Essentially, this means that once the R5 car is
homologated it becomes the responsibility of
engineers in the customer department.
But, as an important manufacturer’s
motorsport wing, does that department have
to show a profit? ‘Of course. It’s a customer
business, it has to show a bit of profit, yes. But
first it’s a car which is done for the image. So,
we have not to lose money, this is true, but if
we can make a bit of profit it’s better. And it
has to be done in this way. But the first thing is
to deliver a good car; reliable, and which can
be used easily by the customer,’ Nandan says.
Just before press time the new customer
department completed eight days testing of
the sole R5 prototype in a fortnight, beginning
CREATIVE MINDS, INSPIRING DESIGN,
PUSHING BOUNDARIES: OUR GRADUATES
ARE READY FOR ANY CHALLENGE!
Department of Mechanical Engineering and Mathematical Sciences
Christopher Roberts studied BSc Motorsport Technology
and is now working for M-Sport as Eric Camilli’s Engineer
Before coming to Brookes I completed a three-year diagnostic course
with Citroen and an apprenticeship as a dealer mechanic. During this
time I started to help a Euro Nascar team, unpaid, on my weekends.
After completing the apprenticeship I joined Ramsport and did a year
as a rally mechanic. I read an article about the new Engineering School
and was taken on a tour of Wheatley Campus during an Open Day. The
facilities were impressive and the level of post-graduates was high, with
strong links to surrounding industry.
Brookes offered a well-balanced education with teaching staff who have
a high level of ability and knowledge. During my studies I continued to
Christopher Roberts (R) briefing Eric Camilli
work as a sub-contracting mechanic in Formula Palmer Audi and FIA
Formula Two. A major factor in landing my first engineering role was
having a combination of industry experience and academic knowledge. I joined AF Corse as a Junior Race
Engineer during my final year at Brookes and left after one year to join M-Sport, initially in the Customer
Engineering Department, with the aim of having a more in-depth role than just the race weekends.
The best moments of my career to date have been:
• competing for the FIA Formula Two championship in 2012 (we finished a close 2nd!).
• working with Jake Dennis when he won the BRDC McLaren Autosport Young Driver Award in 2013.
• winning the WRC2 and Middle East rally titles in 2015 with Nasser Al-Attiyah.
• rallying is much more of an adventure than circuit-racing!
The most challenging moments so far have been stepping up to the works WRC (World Rally Championship)
programme for 2016, running Eric Camilli, who is stepping up to World Championship level with very little
experience. There are many more performance variables to consider compared to circuit racing!
tde.bz/obumems
The Department of Mechanical Engineering
and Mathematical Sciences mixes industry
connections and a history of teaching
engineering. Choose one of our courses at
BSc, BEng, MEng, MSc or PhD level, and
we will start your journey to the top.
Explore what we have to offer - tde.bz/
obumems
Colin McRae’s Subaru World Rally Car
Photo taken on a Brookes visit to Prodrive
Visit us online, take a virtual tour, and watch
videos of our staff and students at our Virtual
Open Day website - tde.bz/obumems-vod
R5 - HYUNDAI I20
Wheel arch space at the front is not free and headlamps must remain standard. This has caused Hyundai and the other R5 manufacturers problems with wheel travel at the front end of their rally cars
on tarmac near Turin, then moving directly
to Sardinia for two days on tarmac and three
days on rough gravel. Test development on all
surfaces continues while a second prototype is
under build, which Customer Racing manager
Andrea Adamo says will aid development
toward a final specification. ‘In some areas we
are developing two designs at the same time,
but with only one car. Having a second chassis
will make that process easier. With one we can
concentrate on tarmac testing; with the other
on gravel, and increase the amount of testing
in the final months before homologation.’
WRC crossover
Hyundai is allowed to use the roll cage
and bodyshell from the existing 2016 New
Generation i20 WRC for the R5: ‘It’s a way also
to save a bit of time and not to do double
work; for instance, body calculations and
things like that,’ says Nandan. ‘But all the rest
is completely different, and it can’t be similar
because of the regulations,’ he stresses.
Nandan is the first to admit that the team’s
2015 WRC car, based on the previous level i20,
was forced to be something of ‘an acceptable
compromise’, because of logistical and time
constraints. Its Global Engine was based on
the all-alloy turbo 2-litre unit from the US
and Korean market Genesis coupe, while
the engine in the current, very competitive,
i20 WRC is an all-new Global unit developed
through collaboration between Hyundai
Motorsport and French firm Pipo Moteurs.
The i20 R5 also gets the Genesis coupederived all-alloy unit; in R5 guise developed by
Pipo and stroked down to 1.6-litre. The team
is currently investigating several different
production turbochargers for its R5 engine
from different manufacturers. To reduce cost,
many engine sensors are standard, and the
engine ECU is the Magneti-Marelli SRG unit
used on the 2015 i20 WRC.
While boost pressure in a WRC engine is
controlled by electronics, for R5 an FIAspecified pop-off valve is required to maintain
pressure below the mandatory 2.5bar
maximum. This is a problem for the engine
engineers, as Nandan explains: ‘It’s totally
different [to WRC] because the boost pressure
is regulated by the pop-off valve. The pop-off
is something mechanical and it’s very difficult
to be very close to the limit. And when the
pop-off opens the pressure’s gone, so it’s a bit
more difficult to regulate it – but okay, it’s the
same problem for everybody.’
The R5 engine is a high efficiency
competition IC unit designed to operate
An FIA-specified pop-off valve is required to keep
pressure below the mandatory 2.5bar maximum
effectively at a gamut of temperatures
and altitudes and a over a wide variety of
distances, so maintaining the correct
temperatures is an absolute priority.
Here the R5 regs bring in more headscratching for the designers. For cost reasons a
WRC-style cooling package is outlawed by the
requirement that R5 cooling components must
emanate from a standard mass production
car. Nandan: ‘This is another point which is
not easy. So you have to find some good cars.
Okay, it is open; you can choose from any
brand or manufacturer, but it has to be a mass
production radiator, intercooler and things
like that. So, it’s not so easy to find something
that’s giving the right performance.’
Arch enemy
Another design headache produced by the R5
rules is that wheelarch space is not free, as it is
for WRCs. This includes the rule that headlamp
pods must be standard, which causes
problems for all R5 teams: ‘It is a problem,
and in this case it is at the front, because now
headlamps are bigger and bigger and these
are taking up a lot of space in the wheelarch.
But from the regulations you can’t do anything;
you just have to use the standard components
and so it is limiting the bump travel a lot at the
front. But I think everybody else has more or
less the same problem,’ Nandan says.
During early R5 developments, while
M-Sport struggled with Fiesta headlamp
pod-to-top-of-front-tyre clearances – which
THE BEST SUSPENSION FOR:
Rally - RallyCross - AutoCross - RallyRaid - MotoCross
Reiger Suspension BV
Molenenk 5a
NL - 7255 AX Hengelo Gld.
- SidecarCross - Enduro - Trial - Quads
Tel. : +31 (0)575-462077
[email protected]
Turbo for champions
The choice of 16 European champions in rallycross over the years. Custom-built to the highest standards,
by our skilled professional staff, to suit your specific engine set-up. Restrictors available to suit.
www.gikturbo.com [email protected]
tel +46 31 571220
fax +46 31 572027
R5 - HYUNDAI I20
The car’s aero package is similar to that of the 2016 i20 WRC. Its transmission architecture
is also similar, with no centre differential, and mechanical limited slip diffs front and rear
ended up at 0.5mm on maximum bump
– the implications of these rules on Skoda
Motorsport’s slightly different headlamp fixing
bracket arrangement meant the team would
have to cease development of the Fabia R5.
The FIA then allowed modifications to the
brackets, enabling the Fabia development to
continue. But in the case of the i20 R5 those
brackets don’t interfere; it’s just that the big
headlamp pods are in the way. Hence, like its
rivals, the i20 R5 enjoys sufficient rear wheel
travel, and suffers from not enough at the front.
There is less freedom in R5 engine
placement compared to WRC, too, and the size
of the i20’s ex-2-litre unit restricts its engine
compartment position further. Nandan: ‘There
is not a lot that you can do, but I think it’s more
or less the same for everybody, depending on
the engine they are using.’
The Hyundai R5 engine and its ancillaries,
including cooling package, is at least 15kg
heavier than the WRC’s, and not as ideally
sited, which results in a front-biased weight
distribution compared to the WRC car.
The car’s aerodynamic package is more or
less the same as that of the 2016 i20 WRC, the
team capitalising on the results of the World
Rally Car aero development work for the R5.
Cost considerations demand minor changes
involving the need not to change parts too
often, together with different sized regulation
frontal openings in the R5 rules. In essence
most changes are at the front.
While the New Generation i20 WRC runs a
6-speed Sadev gearbox and diffs, for the R5’s
regulation 5-speed unit Hyundai Motorsport
has opted for Ricardo assemblies. Apart from
the number of ratios the R5 transmission
architecture is similar to WRC; no centre diff
and mechanical limited slip diffs front and rear,
with a rear axle disengage mechanism.
The latter operates hydraulically in the
i20 R5, similarly to that in the WRC, but using
different components. And, because only
positive preload changes are allowed in
R5, axle differential adjustments are not as
widely variable as they are in WRC, where two
adjustments are allowed. The steering rack
contains Hyundai components, quite possibly
from the Santa Fe model, which are assembled
into an i20 R5 rack in-house.
Works involvement
The majority of R5 cars are run by private
and semi-private teams, although Skoda
Motorsport and M-Sport World Rally Team do
enter ‘works’ R5 cars in WRC2. Each team has
different reasons for this. Skoda is a member
of the Volkswagen group and VW Motorsport’s
WRC involvement – with recent consecutive
World Rally Championship victories for both
the VW Polo R WRC and VW driver Sebastien
‘You have to use standard components, so this
is limiting the bump travel a lot at the front’
Ogier – effectively excludes the Czech team
from running World Rally Cars.
As for M-Sport, managing director Malcolm
Wilson is the first to admit that involvement in
the WRC is crucial to keeping his burgeoning
business alive. From 1997 M-Sport very
successfully ran Ford’s official WRC team. Then
the Blue Oval pulled the funding from the 2013
season. Wilson bit the bullet and funded World
Rally Championship campaigns, chomping
even further into the projectile by capitalising
on the then-new R5 regulations.
The Fiesta R5 eclipsed every rival; on
announcement date, and competitiveness
and reliability. Today, with the Fabia R5 now
out on stages, as the build list of Fiesta R5s
heads toward unprecedented and remarkable
heights, approaching 200 units, it is hardly
any surprise that M-Sport runs top Welsh
driving talent Elfyn Evans in an official
works M-Sport Fiesta R5 Evo.
Just after Hayden Paddon netted a
stunning first WRC rally victory for him and
the New Generation i20 WRC on this year’s
Rally of Argentina, Nandan stressed his team’s
emphasis on R5 is entirely in-line with the
intentions behind the economy second-tier
WRC2 R5 formula, and it’s not looking at a
works effort. ‘As a manufacturer involved in
the World Rally Championship then R5 is a
proper customer project and customer car,’
Nandan explained. ‘We will, of course, assist
and support teams which want to have
a car, but we’ll never do a kind of official
championship, not Hyundai Motorsport.
It’s not our spirit at all,’ he says.
NEW Autosports Sensors
8 mm D-Shaft
Hall Effect
Rotary Sensor
BATTERY ISOLATORS
POWER DISTRIBUTION
FIA RAIN LIGHTS
WIRELESS CONTROLS
SHIFT LIGHTS
GEAR INDICATORS
•
•
•
•
•
•
Hall Effect non-contact technology
Long life - extremely robust
Programmable angles from 30º up to 360º
IP68 protection
Selectable mounting options
Redundant output
CLICK HERE TO VIEW ALL PRODUCTS
Email: [email protected]
Web: www.variohm.com
Tel: +44(0)1327 351004
CONNECTED TO THE TRACK
:KHQ\RXLQYHVWLQDVHWRIWKHZRUOGVƋQHVWKLJKSHUIRUPDQFHVLOLFRQHKRVHV\RX
DUHQRWRQO\XSJUDGLQJ\RXUFDU<RXDUHFRQQHFWLQJWRDIHHOLQJDQDWWLWXGHDQGD
GULYLQJWKULOORQO\6$0&2VSRUWFDQJLYH\RX$UH<28FRQQHFWHG"
VICTORY
#GETCONNECTED
Silicone Hoses handcrafted in Britain. Victorious around the world. For the full range and to check availability for your car visit
Samco_connected_A5_final.indd 1
samcosport.com
26/10/2015 12:40
DAKAR – PEUGEOT 2008 DKR16
Skin deep
Peugeot’s 2016 Dakar winner is wider, longer, lighter
and faster than its 2015 challenger – and yet, as Racecar
discovered, underneath it’s essentially the same car
By ANDREW COTTON
P
eugeot returned to rallying in 2015
with its 2008 DKR that first featured
in Racecar Engineering V24N12. It
marked the brand’s return to top
level international motorsport for the first time
since the cancellation of its Le Mans programme
in 2012, and also offered a better return on
investment with rallies in all of its key markets,
including South America and China.
The team opted for a two-wheel-drive
concept which allowed it to use bigger wheels, a
lower weight car, and run with more suspension
travel, but on tough terrain the vehicle would
struggle for traction compared to its 4wd
competitors. Yet for the 2016 version, the team
stayed with the concept, and its faith was
rewarded with a well-deserved win.
The 2016 car actually looks significantly
different to the 2015 car. It’s wider and longer
by 20cm to improve lateral stability, but it
maintains the two-door coupe concept, and
under the skin the team actually stayed with its
original concept throughout the car.
‘The concept of the 2015 car was very good,
it was one of the conclusions that we made
after the 2015 Dakar race,’ says Peugeot’s
technical director, Bruno Famin. ‘It is the
same engine, same gearbox, same rearwheel-drive concept, big wheels, on modern
suspension. After that, we just wanted to
improve the car in all the possible ways.
‘One of the main weak points of the
previous car was the lack of lateral stability,’
Famin continues. ‘One of the conclusions was
to increase the width of the car by 20cm to the
maximum allowed by the regulations, but you
cannot do it just like that; you have to increase
the wheelbase by more or less the same value.
Already, when you decide that, even if you are
still with the same concept, when you increase
the wheelbase and width by 20cm, you have to
more or less redesign the car! That is not very
difficult because it is a tubular chassis, but it is
very useful because, with the first experience,
we used the opportunity to redesign the parts
and make them lighter, make the car easier
to maintain. Then, the car is also significantly
lighter, even though it is bigger on the ground.’
The team also took the opportunity to
further reduce the front and rear overhangs, and
worked on the aero for the car too. The 2008
DKR16 benefits from improved aerodynamics:
the bonnet and roof-mounted air-intake have
been heavily revised in order to provide more
balanced downforce between front and rear.
The new air scoop also ensures better airflow.
Other evolutions lie under its carbon skin.
The suspension has been redesigned to deal
more effectively with the different and rough
terrains. It also benefits from better weight
“You can never say that you are completely
ready for the Dakar, because you simply
never know what it will throw at you, but
certainly this time we were more ready”
Modifying tubular chassis was a relatively simple affair as it is easier than working on carbon, but a redesign was required
nonetheless. The car is also lighter than 2015 version as the team made uses of lessons learnt to redesign some parts
distribution, as well as magnesium one-piece
wheels for the first time, matched to lighter tyres
from Michelin. These replace the aluminium twopiece wheels from 2015, with the combination
resulting in a significant weight saving.
The new car had been steadily developed
since the first version finished the Dakar Rally
in Buenos Aires in January 2015. Peugeot’s
engineers went over their ‘Lion’ piece by piece,
analysing what could be done better, with the
help of its Dakar experts Stephane Peterhansel,
Carlos Sainz and Cyril Despres.
These improvements were gradually
applied and assessed through a series of tests,
culminating in a one-two finish for Peterhansel
and Despres on the China Silk Road Rally, using
an interim-specification car. This was essentially
the 2015 model with a number of development
components for 2016 added.
‘We tested and raced in China where we
finished first and second without a single
problem,’ says Famin. ‘The competition level
was not as high as Dakar or Morocco, but it was
very good to make special stages without any
problems. What we validated there was the
lightweight wheels with the magnesium rims,
monobloc [one-piece], and the new commercial
tyres from Michelin. We also had a better engine
in terms of driveability, even if it was not the final
version. They were the key points.’
Low grunt
Front and rear overhangs were reduced even further but the main difference between the DKR16 and its predecessor is that
it is wider and longer with a lower centre of gravity. The roof-mounted air-intake has been the subject of aero development
While 2015 (left) and 2016 cars are visually different the new DKR sticks with the underlying 2wd turbo-diesel philosophy
The team worked hard on the development of
the 3-litre V6 turbo-diesel, finding that it lacked
torque at low revs, partly a result of running first
gear ratios that were just too long. That meant
poor driveability at low speeds, and so it made a
series of improvements to the new car.
‘The gearbox is exactly the same, except
the ratio,’ says Famin. ‘The engine has very little
torque at low revs, and the first gear ratio was
too long. The low revs performance of the car
was very bad, especially when you go higher
and higher with altitude. We are better now; the
engine improved a lot, especially at low revs.
We worked a lot on driveability, not so much on
power, and on the gears with the same aim.’
With budget in mind, the Peugeot team
had to be careful with its engine development.
From its days in the Intercontinental Le Mans
Cup (ILMC) and at Le Mans, it knew that the air
restrictor has only a limited effect on outright
diesel engine performance compared to
gasoline. However, Peugeot’s engine is almost
entirely production-based, and so has a natural
cut-off point in terms of development.
‘The base of the engine, the cylinder heads,
blocks pistons, con rods is all standard,’ says
Famin. ‘It is a standard engine. Then you have
to limit yourself in terms of turbo pressure if
you want the pistons to survive. Then the turbo
pressure is limited not by rule, but by engine
basis, and in our case it is strictly standard.’
Famin also says that the development has
been throughout the car: ‘There isn’t one big
www.zomermotorsport.com
[email protected]
tel. 0031 (0)548 - 361385
a potential winner, from start to podium
ZomerMS_Adv_92,5x136_2014.indd 1
Radial Racing UK Ltd are suppliers of Aerospace quality Rod
End and Spherical bearings to the Motorsport Industry.
We have a comprehensive range of Motorsport bearings
including Radial Rod end and Spherical bearings, Wheel
bearings including Taper Roller bearings, Ball bearings,
Needle Roller bearings, Oil seal, Circlips and Locknuts
[email protected]
Tel: +44 (0) 1743 762830
www.radialracing.co.uk
20-05-14 15:15
The DKR15+ raced to first and second in China
but with limited opposition – yet this at least
proved new parts for the 2016 DKR were reliable
In a bid to get down to the minimum weight limit Peugeot opted for
one-piece magnesium wheels and lighter Michelin tyres; but 2008
DKR16 is still above the limit despite these and other measures
The off-road programme
continues to offer better
value for money for the
brand than Le Mans
change that we have made on our car; instead
it has been a series of small evolutions in
different areas, which together we hope will
amount to an overall improvement. The areas
we have concentrated on include bodywork and
aerodynamics – as a result of which the car looks
slightly different compared to last year – as well
as engine and suspension, which is all under the
skin. The tests we have carried out up to now,
as well as our one-two finish in China, indicate
that we are heading in the right direction. You
really cannot compare our state of preparation
[for Dakar 2016] to how it was for our first Dakar,
when everything was new to us. Of course, you
can never say that you are completely ready
for the Dakar either, because you simply never
know what it will throw at you, but certainly
this time we are more ready.’
Famin was speaking in the run-up to Dakar
2016, where one of the Peugeots, in the hands
of Peterhansel, emerged victorious, Peugeot’s
first win in the event since 1990. The car also
performed well in the hands of team mates
Carlos Sainz and Sebastien Loeb.
Peterhansel has said of the 2008 DKR16: ‘You
can really feel the difference now that the car is
longer and wider, with a lower centre of gravity,
because it’s a lot more stable so cornering
speeds are faster. You can feel the difference in
the engine as well: not only is it more powerful,
but you can also use all the power even at low
revs. We’ve almost got a ‘problem’ now of how
to manage all that power most effectively, but
this is a very nice problem to have.’
Carlos Sainz put in many hours of
development work before the Dakar. As a result,
he accumulated plenty of experience of the
brand new challenger. The Spaniard said before
the big event: ‘It’s been good testing and the car
has been running really well. The potential of
the car is much, much bigger than it was at this
time last year and reliability has been solid too.
We’ve changed quite a lot in the car in many key
areas, so really we can call this one a completely
new car compared to last year.’
The off-road programme continues to offer
better value for money for the brand than the
Le Mans programme, but the desire to return to
endurance racing still burns bright at Peugeot
Sport, which is keen to address what it sees as
unfinished business. But cost control measures
must come into force before it can contemplate
a return to Le Mans, possibly when there is a
major chassis change in 2018 or new fuel rules
in 2020. In the meantime the 2017 Dakar car is
already on the drawing board and that is where
the company’s priorities lie in the medium term,
hoping to build on its superb win this year, its
first in the event for quarter of a century.
Famin will hope that the new car will not
have to be that different from 2016, further
validating the team’s radical concept.
Innovation
Experience
HIGH PRECISION CNC MACHINING &
W I N D F O R M A D D I T I V E M A N U FA C T U R I N G
Automotive application, combination of Windform Additive Manufacturing and high-performing CNC Machining.
Courtesy of Ilmor Engineering
CELEBRATING OVER 45 YEARS OF PRODUCING EXCELLENCE
Our Italian craftsmanship and professional skills make
us the choice partner in gaining technical advantages in
High Precision CNC Machining and Advanced 3D Printing Service
that few others can guarantee.
Producing quality, reliability, innovative solutions and speedy delivery
service are our distinguished features.
www.crp-group.com
LONG-STANDING EXPERIENCE
[email protected]
WRC R-GT – ABARTH 124 RALLYE
Little wonder
For those looking for rear-wheel-drive thrills
in the WRC, the R-GT class is just the ticket.
Abarth’s diminutive 124 Rallye is the category’s
first proper works-developed rally car
By SAM COLLINS
T
here is a third top level in the WRC
that sits below World Rally Cars and
R5, and for some years now it has
largely been overlooked. It officially
fits under the Group R regulations, but it is
unlike anything else covered by those rules. It is
R-GT. Until now only a tiny number of cars have
been built to the rules, some privateer Porsches
and an abortive Exige variant from Lotus. But
then, at the Geneva Motor Show in early 2016,
the Fiat 124 Abarth Rallye was revealed.
Most in the media believed that this 124
was a mere concept car, or a show car. Those
who did think it was the real deal believed it
was designed to the R3 regulations, where it
would go toe-to-toe with the likes of the TMG
built Toyota GT86. But Abarth is not doing
things by half, and this is in fact the first serious
manufacturer car built to the R-GT regulations.
Maurizio Consalvo, Abarth technical
development manager, says: ‘We want to use
this car to go back to the roots of rallying, so that
is our mission. We are launching a rear-wheeldrive car into an all-wheel-drive or front-wheeldrive world. But for the enthusiast an AWD or
fwd car is not the ultimate in terms of spectacle,
its all about rwd. Its an emotional engagement
and we are emotionally engaged.’
The new Abarth 124 rally car is disarmingly
small, especially when the potency of the
engine is considered, and it’s telling that
Consalvo speaks of the engine first. ‘The engine
is the most important aspect of the car. We have
installed the turbocharged DOHC 1.8 direct
injection 4-cylinder, we call it the Bialbero. It
produces around 300bhp depending on the
settings chosen by the driver [via a steering
wheel mounted control]. It is the same engine
architecture used on the Alfa Romeo 4C, but we
tuned it for the best output in competition.’
The production car has both the mild Fiat
variant and a more highly tuned Abarth version,
and in developing the new rally car the Italian
engineers wanted to keep things close to home.
‘What makes this car so different is that it is so
close to the production car,’ Consalvo says. ‘If you
look at the Polo WRC, it is beautiful engineering
but it is a totally different machine to the car
that is in the showroom. On our car we have a
double wishbone front and a five-link rear, and
that is what you will find on the road car. We
also have a mechanical LSD, all in common
with the production car.’
However, the mechanical components
themselves have little to do with the road
going machine. The transmission is an off the
shelf longitudinal Sadev sequential unit and
gearshifts are actuated pneumatically. Curiously,
the road car and competition car transmissions
have similar weights, according to Consalvo.
Hot Abarth
While the suspension has some general
commonality with the production car, such as
the inboard pickup points, it is also far from
standard. ‘The dampers are bespoke four-way
adjustable units, we can make the travel longer
or shorter depending on if you are on asphalt
or gravel. We worked on the kinematics a bit
but the pick up points are the same so that
was a bit limited,’ Consalvo explains. ‘When you
only have only two driven wheels you need to
get the best traction you can, and that was the
philosophy of the design.’
Ensuring the best traction possible was
also the core aim of the chassis development,
which is notable because the production car is
a soft top. ‘The hard top on the car is specifically
designed for the rally car. It is a composite
construction and bonded to the roll cage to
further increase stiffness. In fact the cage is not
only designed to meet the FIA regulations but it
is also meant to improve the torsional stiffness,
and as such it is linked to the front and rear
suspension turrets. The result of the cage and
the roof is an increase of 30 per cent in terms of
torsional rigidity,’ says Consalvo.
Working to improve the traction from the
The Fiat road car on which the Rallye is based
comes with a soft top so Abarth needed to make
its own hard top to meet FIA regulations. This
also helped increase the stiffness of the chassis
rear wheels has also impacted the layout of
components in the car. ‘The road car and rally
car have almost identical weight distribution,
because on the competition car we have
increased the weight a bit, the big engine
moves weight forward and the cage is heavy,
but we save a lot of weight too in other areas,
Consalvo says. ‘We have got the engine behind
the front axle and also, because this car will
do some very long stages and events on the
WRC, we decided to find the extra space in the
rear of the car to fit two full size spare wheels,
rather than the usual one. This also helps us with
the weight distribution a bit too, as it moves it
rearwards a bit, which aids traction.’
The cockpit of the car is surprisingly large,
with a lot of effort clearly placed on making the
124 as usable as possible, and this has resulted
in the use of an advanced electronic system.
Abarth has clearly outsourced this work but
declined to declare who its partner is. ‘The
interior ergonomics were important, so every
single detail was analysed and adapted so the
steering wheel is more complex perhaps than
The new Abarth 124 rally
car is disarmingly small,
especially when the potency
of the engine is considered
some others, with controls for TC mapping,’
Consalvo says. ‘We have a TFT [flat screen]
display on the logger and dash. It’s a next
generation racing system, we used it not only
to improve functionality but also to reduce
weight. With this system you can make the
adjustments on the car much faster.’
From the car’s development, and especially
the layout of the cockpit, it is clear that the new
Abarth R-GT is not a car for a works assault of
the World Rally Championship, but for privateers
to use to try to upset the big boys. ‘This is not
a car for works teams, this is a car for normal
people who want to go rallying at the top level.
We will go testing with it in September, and
we will be ready for the Monte Carlo Rally in
2017. Our aim is to challenge the R5 cars, but
depending on the restrictor we have there is
the potential to take on the WRC cars in some
conditions,’ Consalvo says.
Manufacturers using R-GT cars cannot score
WRC points but the crews behind the wheel
can, and they can compete for overall wins.
The last serious R-GT effort, Francis Tuthill’s
The turbocharged DOHC 1.8 direct injection 4-cylinder powerplant is called the Bialbero. It produces around 300bhp and it is
actually the same engine architecture as used in the Alfa Romeo 4C. Abarth has tuned the unit for World Rally competition
privately developed Porsche 997, was hit with a
very small restrictor shortly before its debut on
Rally Germany in 2014. Many felt that this was
because the car was not works endorsed and
that it would be a bad thing for a privately built
and run car to mix it up at the front.
However, there is still the belief that if a
works-backed car arrived in R-GT then it would
be given a more generous restrictor and
would be allowed to compete for overall
wins. There are rumours that the Fiat Abarth
will not be alone in the R-GT class in 2017, and
it may be joined by a new car from Alpine.
Whether this leads to a more exciting, breed
of rally car will only be clear on the Monte
Carlo Rally early next year.
TECHNOLOGY – WRC SIMULATION
Slide rules
Add dirt and ice to the equation and the race maths
gets a whole lot trickier – Racecar’s numbers man
grapples with the slippery subject of rally simulation
By DANNY NOWLAN
F
Figure 1: Lateral force vs slip angle characteristic for road tyre. Note how curve drops away once peak slip angle is exceeded
or the last few months my work has
been dominated by a project to adapt
ChassisSim for WRC. The tarmac bit
was easy, but the tough bit has been
adapting it to run on dirt and ice. It has been
challenging, yet also incredibly informative at
the same time. The challenging aspect has been
resolving why you have to run well into the poststalled region of the tyre, and then resolving how
to stay there. But let me state from off; I am not
pretending to be an expert on this. If truth be
told, I’m actually writing this more for me than
you at this point, so I can start to get some things
straight in my head. That being said I’ve learnt a
lot so far, so if you are involved with rallying or
have any interest as to what happens when a car
goes sideways, then please read on.
So here is the question: why do you want to
go sideways in a rally car? For all of us that have
been involved in circuit racing this is a cardinal
sin. It looks impressive, but when it comes to
tarmac racing we all know it’s a guaranteed way
to kill your speed. The answer to this question
lies in what the tyre is doing.
Slip angles
Figure 2: The force vs slip angle characteristics of a rally tyre – this shows there is grip to be had in the post-stalled region
If you want to go fast on a road racing
tyre there is no point in being sideways,
because the grip isn’t there
Specifically, the answer as to why we want to
go sideways on dirt and ice comes down to the
slip characteristics of the tyres. To really hammer
home the point let’s illustrate this graphically – a
typical force vs slip angle characteristic for a road
racing tyre is shown in Figure 1.
The thing to note in this curve is how
significantly the grip drops away after you have
exceeded the peak slip angle. In the post stalled
region this is in the order of 10 to 20 per cent.
Consequently, if you want to go fast on a road
racing tyre there is no point being sideways,
because the grip simply isn’t there.
When you are on dirt and ice the tyre
characteristics are a totally different ball game.
When I was doing my research I came across
two excellent thesis. These were Michael
Croft-White’s thesis from Cranfield University,
Measurement and Analysis of Rally Car Dynamics
at High Attitude Angles, and a thesis from
Stanford University entitled Dynamics and
Control of Drifting in Automobiles by Rami Yusef
Hindiyeh. The upshot from both of these is
that when you are post-stalled the grip doesn’t
drop off that much. White did some basic tyre
modelling from a beta sensor he had developed.
This is presented in Figure 2. The key thing to
note is what is happening in the post-stalled
region. Looking at slip angles well in excess of
20-degrees the grip has only dropped of by 10
per cent. This is significant, because it shows
there is grip to be had in the post-stalled region.
If the drop in post-slip grip is mild the reason
there is grip is because of what happens with the
longitudinal forces of the tyre at large slip angles.
This is illustrated in Figure 3 along with the
equations of motion with the car.
The symbols in Figure 3 are:
Fy1 to F y4 – Lateral forces of tyres 1 to 4 respectively.
Fx1 to F x4 – Longitudinal forces of tyres
1 to 4 respectively
α1 to α4 – Slip angles of tyres 1 to 4 respectively.
δ –Steer angle of the front wheels (equal steer
angles are used on both sides to keep the
representation simple).
FYF – Lateral force applied at the front axle.
FYR – Lateral force applied at the rear axle.
The tyre loads are applied vertically
downwards for each tyre.
All tyre forces are applied along the slip
angle line. FXF and FXR are the sum of all
the longitudinal forces at the front and rear
respectively. Longitudinally this will not have
a huge impact. But as we’ll see shortly it has
big ramifications laterally. This is particularly
apparent at large slip angles.
Sine language
But a note about small angle assumptions here.
Strictly speaking they only apply to about +/10 degrees. However for practical calculation
purposes we can stretch this to about 20
degrees. Let me illustrate what I mean. In radians
20-degree is 0.349. The sine of 20-degree is
0.342. The cosine of 20-degree is 0.94. Yes, we
sacrifice a little bit of accuracy longitudinally
but the sine of the angles are still very close.
Consequently, the equations we are about to
present still work out. The other option is to
include the sine and cosine terms. While it is fully
accurate, the problem is you start to lose any
perspective on what the maths is telling you.
Also, in rallying, it is rare to see a side slip greater
than 30 degrees. While this is not ideal we are
certainly not in fantasy land.
Also, to simplify things we have lumped
in the lateral forces here as well. Using small
angle assumptions Equations 1 and 2 may
be concluded. From the derivation presented
in Wong3 (see references) the slip angles are
Equations 3 to 6. Resolving forces and moments
from Figure 1, the differential equations of the
racecar become Equations 7,8 and 9.
Equations 3 to 9 describe everything about
how the racecar will behave. The thing to note
here is the longitudinal forces. To reiterate they
are applied on the slip angle line of the tyre. At
this point you might be thinking, so what? But
Figure 3: Free body diagram of the forces acting on the racecar showing longitudinal forces of tyre at large slip angles
EQUATIONS
EQUATION 1
EQUATION 2
EQUATION 3
EQUATION 4
EQUATION 5
where;
EQUATION 6
Vy
Vx
r
sideways velocity.
forward velocity.
yaw rate.
EQUATION 7
EQUATION
8
mt (V yʹ + Vx r ) = FYF + FYR + (δ +
α1 + α 2
⎛α +α4 ⎞
) ⋅ FXF + ⎜ 3
⎟ ⋅ FXR
2
⎝ 2 ⎠
EQUATION 9
α + α2 ⎞
⎛α +α4 ⎞
⎛
I z ⋅ r ʹ = a ⋅ ( FYF + ⎜ δ + 1
⎟ ⋅ FXR )
⎟ ⋅ FXF ) − b ⋅ ( FYF + ⎜ 3
2 ⎠
⎝
⎝ 2 ⎠
Here,
m
= Total mass of the car.
t
Iz
= the rotational inertia of the car
Table 1– Rally car parameters
Parameter
Value
Car mass
Cornering g
Peak slip angle: tarmac
Peak slip angle: dirt
CdA
Cornering speed
1300kg
1
60
160
1.1
108km/h
Table 2 - Numbers for the balanced
longitudinal forces in tarmac and dirt mode
Mode
FXT (kgf)
Lateral component (kgf)
Tarmac
Dirt
198kgf
424kgf
20.7
118.7
EQUATIONS
EQUATION 10
FYF _ FXF = (δ +
FYR _ FXR
EQUATION 11
α1 + α 2
) ⋅ FXF
2
⎛α +α4 ⎞
=⎜ 3
⎟ ⋅ FXR
2 ⎠
⎝
FXT =
1
ρ ⋅ V 2 ⋅ C D A + α p ⋅ mt ⋅ a y
2
we have,
Here
Fxt
= Total longitudinal force applied (N)
p
= air density (kg/m3)
V
= Car speed (m/s)
ap
= Peak slip angle in radians
mt
= total car mass
ay
= Lateral acceleration in m/s2
Figure 4: Here two
tyre forces are acting
both laterally and
longitudinally
Figure 5a: Road course tyre. Equation 14 shows us that this tyre has an optimum slip angle of 6.2 degrees
the key lies in the lateral components of the
longitudinal forces – see Equation 10. Here
FYF_FXF is the lateral force at the front
induced by the front longitudinal forces
and FYR_FXR is the lateral force induced
by the rear longitudinal forces.
Where things get really interesting is with
what happens when the slip angles go up. Let’s
illustrate this with some numbers. Let’s consider
a typical all-wheel-drive rally car that weighs
in at 1300kg. Some performance numbers are
illustrated in Table 1. I realise the cornering g on
dirt will be less than tarmac, but let’s keep these
the same for the time being. I want you to get a
feel for the magnitude of the numbers.
So, balancing the speeds and assuming front
and rear slip angles to be the same we have
Equation 11. I know this is not strictly accurate
but it is in the ballpark and, as I’ve said, I’m
doing this so you get a feel for it. Crunching the
numbers for the tarmac and dirt modes you get
the results presented in Table 2.
Engine force
So, in tarmac mode we have about 20.7kgf
of lateral force produced by the applied
longitudinal force. In dirt mode this jumps to
118.7 kgf. While the analysis is incredibly
over-simplified it rams home the rally
observation that on dirt the engine force is
a significant part of your corner grip.
But how do we determine that this is viable
or not? We will enter what I will term the drift
feasibility equation. Let’s illustrate this situation
graphically – this is shown in Figure 4. As can
be seen here we have two equal forces acting
laterally and longitudinally. I will term this force
R(α). Both of these components will have
lateral components. Let me set R(α) out in
Equation 12. Here C(a) is the normalised slip
curve and FmOUT and FmIN are the outer and
inner traction circle radius values. Our goal here
is to find the best compromise of slip angle that
produces the optimum lateral grip. Our total
lateral forces will be given in Equation 13.
Just to be clear, I am slaving the force R(α) to
the force vs slip angle equation that we all know
and love. However, I’m still keeping it in traction
circle limits so that we don’t enter fantasy land.
So the optimum slip angle will be given by
deriving Equation 14 as a function of slip angle;
using the product differential rule it is found that
the optimum slip angle that will produce the
most lateral grip will be given by this equation.
Equation 14 is the drift feasibility equation.
This won’t necessarily tell you the optimum slip
angle you need to be at for drifting. However,
it will tell you if your tyre can actually do it. As
a case in point consider Figure 5a which is a
road course tyre and Figure 5b which is a rally
tyre. Evaluating Equation 14 for both of these
curves show that figure 5a has an optimum
slip angle of 6.2 degrees and figure 5b has an
optimum slip angle of 16 degrees. Try doing this
numerically. List out R(α) and the subsequent
Now we need to nail down at what angle we have to go sideways at
derivatives. If you try and do it analytically you’ll
drive yourself nuts. This is the first step in seeing
if it is worth your while to go sideways or not.
So now that we have established if it’s viable
or not to go sideways we know need to nail
down at what angle we have to go sideways.
Remember we are drifting on dirt and ice not
just because it looks impressive but we are
doing this to get grip. The answer lies in the
lateral grip front and rear.
yields the relation for the rear slip angle we are
after, as seen in Equation 20.
The solution of Equation 20 will give you
a reference check. You are then going to go
through an iterative process to see if this makes
sense. In particular, if it is achievable through the
slip angle curves you have.
The other thing to check is the load transfer,
so that you have the traction. The limitation
will be the inside rear tyre loads. You will then
check Equation 17 and if all this adds up
you have equilibrium. When this all checks
out you have determined the rear slip angle
and side slip angle you should be drifting at.
What all these equations tell you is that
drifting to improve vehicle grip is only viable
in low grip situations.
Let’s re-inspect equation Equation 17, but
this time let’s do it through the lens of load
transfer. As a rough rule of thumb your tyre loads
Front to rear
Let’s put some maths to this. To simplify things
a little bit let’s use the bicycle equations of
motion for the front and rear slip angles. This is
presented in Equation 15. Here αf and αR are
the front and rear slip angles. The front and rear
lateral forces taking into account both the forces
due to slip angle of the tyre and the longitudinal
forces are shown in Equation 16.
Let’s nail down the nomenclature here:
CF(a) – Normalised force slip angle curve
at the front
CR(a) – Normalised force slip angle curve
at the Rear
Fm1 – Traction circle radius at the Left front
tyre for a given load.
Where things get really interesting is taking
the derivative with respect to slip angle of
Equation16. Then we see Equation 17.
In order to be worth your while to drift, the
differential of the front and rear force curves
must be greater than zero. This is where the grip
is and the reason the grip is there is as the slip
angle increases you will actually be producing
force you can use. It’s the reason that you see
Sprint cars on an oval hanging the tail out
because that is where the grip is. If your car is
rear-wheel-drive, the last bit of Equation 17
applies. If your car is front-wheel-drive the first
bit of it applies. If you are all-wheel-drive then
both come into play. For rallying, Equation 17
outlines the appeal of all-wheel-drive cars.
So what is the procedure to determine the
slip angle that you should be drifting to satisfy
Equation 17? You start by choosing a corner
speed and looking at the peak curvature you
want to corner at. You then nominate the factor
of grip you want to maintain at the rear. The crux
of this is that we want to maintain equilibrium
both laterally and longitudinally.
Keeping the slip angles the same front and
rear we have Equations 18 and 19. Here tspR
is the torque split at the rear and FXFR is the
factor of rear longitudinal tyre force we want to
contribute to the lateral grip. Putting 18 into 19
Figure 5b: This time it’s a rally tyre. With Equation 14 we can see this has an optimum slip angle of 16 degrees
EQUATIONS
EQUATION 12
R(α ) = C (α ) ⋅ (FmOUT + FmIN )
EQUATION 14
∂Fy
∂α
= 0 = R(α ) ⋅ (cos(α ) − sin (α )) +
EQUATION 15
αF = δ −
αR =
Vx
FYF = C F (α ) ⋅ (Fm1 + Fm2 ) + (δ + α F ) ⋅ FXF
Vx
a ⋅ r + Vy
b ⋅ r − Vy
∂R
⋅ (cos(α ) + sin (α ))
∂α
EQUATION 16
a ⋅ r + Vy
δ = αF +
EQUATION 13
FYT = 0.707 ⋅ R(α )⋅ (cos(α ) + sin(α ))
Vx
a ⋅ r + Vy
⎛
= C F (α ) ⋅ (Fm1 + Fm2 ) + ⎜⎜ 2 ⋅ α F +
Vx
⎝
FYR = C R (α ) ⋅ (Fm3 + Fm4 ) + (α R ) ⋅ FXR
⎞
⎟⎟ ⋅ FXF
⎠
EQUATION 17
∂ (FYF ) ∂ (C F (α F ))
=
⋅ (Fm1 + Fm 2 ) + 2 ⋅ FXF
∂α F
∂α
∂ (FYR )
= C R (α R ) ⋅ (Fm3 + Fm 4 ) + FXR
∂α R
EQUATIONS
EQUATION 18
α R ⋅ FXR = FXFR ⋅ wdr ⋅ mt ⋅ VX 2 ⋅ iR
EQUATION 19
⎛1
⎞
2
FXR = tsp R ⋅ ⎜ ⋅ ρ ⋅ V 2 ⋅ C D A + α R mt ⋅ V X ⋅ iR ⎟
⎝2
⎠
EQUATION 20
αR
2
0.5 ⋅ ρ ⋅ C D A
F
+
⋅ α R − XFR = 0
mt ⋅ iR
tsp R
EQUATION 21
2
1
prr ⋅ mt ⋅ a y ⋅ h
wdf ⋅ mt ⋅ g awf ⋅ C L ⋅ A ⋅ 2 ⋅ ρ ⋅ V
TL1 =
+
+
tm
2
2
2
prr ⋅ mt ⋅ a y ⋅ h
wdf ⋅ mt ⋅ g awf ⋅ C L ⋅ A ⋅ 1 2 ⋅ ρ ⋅ V
TL 2 =
+
−
tm
2
2
2
1
(1 − prr ) ⋅ mt ⋅ a y ⋅ h
wdr ⋅ mt ⋅ g awr ⋅ C L ⋅ A ⋅ 2 ⋅ ρ ⋅ V
TL3 =
+
+
tm
2
2
2
1
(1 − prr ) ⋅ mt ⋅ a y ⋅ h
wdr ⋅ mt ⋅ g awr ⋅ C L ⋅ A ⋅ 2 ⋅ ρ ⋅ V
TL 4 =
+
−
tm
2
2
EQUATION 22
a⋅
SI =
∂FYF
∂F
∂F
∂F ⎞ r
⎛
− b ⋅ YR − ⎜ a 2 ⋅ YF + b 2 ⋅ YR ⎟ ⋅
∂α ⎝
∂α
∂α ⎠ V X
∂α
∂F ⎞
⎛ ∂F
⎜ YF + YR ⎟ ⋅ wb
∂α ⎠
⎝ ∂α
for a given aero load and load transfer are given
in Equation 21. Where the downforce is not
significant what will limit you will be the inside
front and rear tyres unloading. Consequently
your ability to apply the longitudinal forces you
need, to ensure Equation 17 is greater than or
equal to zero, will be limited. Strictly speaking
you could channel all the longitudinal force
to the outside rear wheel, but you will have a
destabilising moment due to the tractive force
trying to destabilise the car.
The drift zone
The last topic to touch upon is; what does
the racecar stability look like in the poststalled drift zone? As discussed in some of my
previous articles, there is an excellent tool to
look at this, which is the stability index. This can
be written as Equation 22.
Inspecting Equation 17 and putting it into
Equation 22 we will still have some measure
of stability. However, it will be much more
marginal. This is because the slope of the force
vs slip angle curves are much smaller. The
applied longitudinal forces are the dominant
terms. The combination of Equations 17 and 22
mean that if you are sliding in a rear-wheel-drive
car you have no option but to keep the power
applied. This was also confirmed in Hindiyeh2,
where the engine force is used as an integral
part of his drift controller.
Lastly, to show this isn’t just theory, the
beginnings of it have now been incorporated
into ChassisSim, as you can see in the example
of a predictive rally simulation done in real time
controlling the car in the post-stalled zone of
the tyre, shown in Figure 6.
The first trace is speed, the second is steered
angle, and the third trace is throttle. However,
the real traces are the fourth and fifth traces that
show front and rear slip angles. The stall angle
for this tyre is six degrees. The front slip angles
are in the order of four to five degrees. However,
you can see the rear slip angles are in the order
of 10 degrees and they are being controlled. I
should add that the car model needs work.
In closing, the vehicle dynamics of drifting
are an exceptionally interesting field. The thing
that dictates why you want to drift is what
happens to the tyres on dirt and ice. Here the
slip angle curves drop of moderately in the
post-stalled region of the tyre. This makes it
viable to slide and we can readily calculate
where we need to be drifting.
While this is certainly not the last word on
the vehicle dynamics of rallying, I trust what I
have given you is the mathematical framework
to put some numbers to it.
Figure 6: Some predictive rally action from ChassisSim which shows the car being controlled in the post-stalled drift zone
References
If you’re sliding in a rear-wheel-drive car here,
you have no option but to keep the power applied
1) Measurement and Analysis of Rally Car Dynamics at High
Attitude Angles, Michael Croft-White, Cranfield 2005.
2) Dynamics and Control of Drifting in Automobiles,
Rami Yusef Hindiyeh, Stanford University 2013.
3) Theory of Ground Vehicles, JY Wong Wiley
and sons, 1978
The UK’s largest meeting place for advanced
engineering professionals
Join us where
the familiar
and the
collidecorridors
to
“Fantastic…I
think
thisunfamiliar“…the
provide new
opportunities
across
the
engineering
supply
is the best year yet”
and they are our
chain. Dave Withey,
Graham Mulholland,
Senior Project Engineer, Research,
“Fantastic…I think this
is the best year yet”
Dave Withey,
Senior Project Engineer, Research,
Jaguar Land Rover
Managing Director,
Advanced
Engineering
is the industry eventepm:
where
Jaguar
Land Rover
technology group
high-technology manufacturing sectors converge under
“…the
been full all the time,
one
roof tocorridors
meet andhave
do business.
and they are our decision makers”
Graham Mulholland,
Managing Director,
epm: technology group
“Fantastic show - lots of interest, not just from
aerospace but from automotive and other
sectors”
Robert Richards,
BDM, Metrology
Software Products
“Fantastic show - lots of interest, not just from
aerospace but from automotive and other
sectors”
Robert Richards,
BDM, Metrology
Software Products
“It w
min
spo
got
Mark
“It was fantastic to meet with likeminded people - especially in motor
sports and hybrid power…We’ve
got some great leads to follow up”
Mark Harbord, Sales & Marketing Manager, LCL Electronics
Contact us about exhibiting today gg
+44 (0)20 8843 8800 or visit www.advancedengineeringuk.com
WRC – 2017 CONTENDERS
The stage is set
A new breed of quicker and more spectacular World Rally Cars will be
unleashed next season. But where do the manufacturer teams currently
stand in the 2017 development race? Racecar investigates
By MARTIN SHARP
The extended body width of the next generation
2017 WRCs provides increased space to
enhance side impact protection for crews
H
ere are the headline figures
concerning next year’s new WRC
regulations. Close to 50bhp more
power than this year (to 380bhp),
from a turbo inlet restrictor diameter increase
from 33mm to 36mm for the 1.6-litre 4-cylinder
engines. Minimum car weight goes down by
25kg, and handling and traction improvements
come from a central differential with active
slip-limiting. The cars will also be 55mm wider.
Meanwhile, aero changes include increased
dimensions for the fixed rear wing, with an
extra 30mm overhang allowed. A 60mm front
overhang is also permitted, and the rear diffuser
design is free, within maximum dimensions.
These new rules were approved by the FIA
WMSC on July 12 last year and Volkswagen
Motorsport was the first top team to test
designs and development components for its
2017 World Rally Car. Its first test was in Finland
last August, just one month after the new
rules were approved. Given the time scale it is
impressive that the test car appeared with wider
versions of the 2015/16 wheel-arch extensions,
development wider track suspension, and
an intermediate, active centre diff-equipped
transmission solution. By this year’s Rally
Portugal the team had completed ‘more than
5000km, less than 10,000km,’ of testing, says VW
Motorsport’s chief chassis engineer FrancoisXavier ‘FX’ Demaison, rather enigmatically.
‘Because of the more open rules for the
suspension and geometry we tested different
options,’ Demaison says. ‘The best compromises;
the best way to increase the track width and
the maximum potential we could get out of the
more freedom we have for suspension pick-up
points. That was the purpose of most of the tests
we did last year with so many different specs,
but last year it was not really a 2017 car.’
VW’s early start
Such continuously honed specifications enabled
Demaison to consider it prudent to sign off the
final car spec by mid-2016. ‘In October we have
to give a final document, but we want to start
in January with three cars at Monte Carlo. So, if
we have three cars then we have [to have] the
spares, and we have also Rally Sweden three
weeks later. If we have bad luck in Monte Carlo
and we crash three cars, we need also spare
chassis’ ready for Sweden.
‘We are in the validation phase for the
transmission, for the suspension, for the
Citroen has taken a sabbatical from the
WRC this year to concentrate on the
development of its 2017 car. The aero
on the new C3 rally car has benefited
from the company’s WTCC experience
Because the Yaris WRC will be freshly homologated as a World
Rally Car for 2017, the rules allow Toyota to have an unlimited
testing programme in the run-up to its top level rallying comeback
The current spec Fiesta WRC. M-Sport is testing many of the
components for the 2017 Ford on a 2016 car, which it says has a
very similar chassis and suspension geometry to the new Fiesta
bodyshell, the cooling, everything. The only
thing which is not tested yet on the car is all of
the bodywork,’ Demaison adds.
This is because, at the time of writing, the
manufacturer teams and the FIA were discussing
the side impact protection of the new cars. The
tragic death of co-driver Michael ‘Beef’ Park after
Markko Martin’s Peugeot 307 WRC hit a tree
sideways in the Margam Park stage on the 2005
Wales Rally GB convinced the FIA to mandate
specific deformable impact-absorbing foam in
driver and co-driver side doors. But at the time
the doors remained standard thickness, so there
was limited space for the foam.
The extended body width of the next
generation 2017 WRCs provides increased
space to enhance side impact protection
for crews. It is a manufacturer team-driven
campaign, and meetings between the FIA and
teams have made some progress, but before a
final ruling the requirements of each car model
need to be taken into account.
Foam call
Demaison says: ‘For sure, we increase the car by
55mm compared to today, so it’s 27.5mm per
side, so yes there is room. It’s always a fight with
designers in the road car department; they do
not want us to change the shape too much, but
for safety reasons we will do it.
‘We’re talking with the FIA, just to find
a solution which – because all the cars are
different – gives all cars the same level of
safety and protection. That’s the most difficult
thing. So that’s why we do it together; all the
manufacturers. We can check on our car and say
yes or no; this we can’t do, this we can do, and
have a final decision,’ Demaison adds.
Currently the FIA has suggested mandating
a further 30 litres of deformable foam in each
front side door to the existing 60 litres. This
is still yet to be ratified by the FIA WMSC, but
will likely include the possibility to increase
door thickness for those cars which cannot
accommodate 90 litres of foam in each side
door. It is, however, possible that further side
impact protection provisions will also ensue.
Active differentials were part of the old 2-litre
turbo World Rally Car designs. Then the 1600cc
turbo regulations demanded passive front and
rear axle diffs and no centre differential. Under
the 2017 rules the passive axle units remain, but
an active centre differential is again allowed.
Demaison explains why: ‘We mainly pushed
WRC – 2017 CONTENDERS
transmission during the week after Rally
Portugal, and planned to test this a week
later, after rig testing had proven gearbox and
differential components. Its 2017 tests began
in April, using a 2016 five-door i20 WRC, as
Hyundai Motorsport team principal Michel
Nandan explains: ‘We have dedicated one
car to do all this; a ‘mule’ car in order to test
some components and not wait until the 2017
bodyshell; not to lose too much time.’
Hyundai’s progress
Citroen has experience with the Global Race Engine (pictured) it will use in the WRC from its programme in the WTCC,
where it also runs with a 36mm inlet restrictor as per 2017 WRC regulations. Power goes up by 50bhp to 380bhp next year
for this because it’s for us like having a proper
damper in the drivetrain, which causes much
less technical issues with driveshafts, with the
propshaft, with the internal parts of the diffs.
That’s the main thing, and we all agreed to have
a very simple and basic active strategy.’
This will likely contribute to making the
more powerful and lighter 2017 cars somewhat
more controllable in corners. But will the cars
then look more as if they are cornering on rails?
There is internet video footage of some 2017
WRCs on test already, and this is Demaison’s
expert opinion: ‘The movies we have seen of the
’17 cars on gravel, and even on tarmac, for me
they look a bit more spectacular.’
But he also makes the point that early tests
are development exercises; not demonstrations
of ultimate pace. Volkswagen Motorsport’s three
WRC drivers have already tested the 2017 car
specification, but the bulk of the test driving
tasks are undertaken by twice World Rally
Champion Marcus Gronholm: ‘When we have
Marcus testing, he is not driving at the same
speed as [Sebastien] Ogier, Jari [-Matti Latvala]
or Andreas [Mikkelsen]; it’s not what we’re
asking. He doesn’t need to push 100 per cent,
Volkswagen’s first test
was in Finland last August,
just one month after the
new rules were approved
it’s not his job; we need really good technical
feedback from him,’ explains Demaison. He says
the same of early footage of Toyota’s 2017 WRC
testing in Finland and Spain, with four-time WRC
Champion Tommi Makinen behind the wheel.
Toyota’s advantage
Because the 2017 Toyota Yaris WRC will be
freshly homologated as a World Rally Car the
rules allow works team, Tommi Makinen/Gazoo
Racing to have no limit on the amount of
pre-season testing allowed, and it is the same
for Citroen Racing with its C3 WRC, which will
also be a new car to WRC homologation. This
freedom is not available to VW Motorsport,
which will be homologating the same,
victorious, three-door base Polo, as campaigned
in previous seasons, as its 2017 WRC.
Which is partly why the team started
testing early, Demaison says: ‘We were limited
in the number of days testing, so it’s quite a
disadvantage. We are were limited because it
says in the rules that if you keep the same model
you have limited testing. We had 30 days for
both 2015 and 2016, so 15 and 15 for each year.’
But how far ahead of his rivals does
Demaison consider VW to be? ‘This is really
difficult to say: are we ahead? We don’t know.
We are doing the work we think is necessary to
be ready for Monte Carlo and we will judge in
Monte Carlo. But before that it’s really difficult
to know [how we compare] with the red ones,
Citroen, with the experience they have.’
Meanwhile, Hyundai Motorsport took
delivery of its 2017 specification Sadev
Engine components, a bigger restrictor, and new
coolers have already been tested in this way
by Hyundai. The 2017 wider track suspension
is designed but yet to be tested, but it plans
to build a full 2017 specification car ready for
testing around July time, 2016.
That 2017 specification Hyundai WRC will be
the three-door coupe version which the team
originally planned to be its 2016 challenger. It
started testing with it, then realised production
figures for the 25,000 minimum required for the
model would be marginal for 2016. So Hyundai
Motorsport opted for the five-door i20 as the
base for is 2016 WRC challenger.
But the manufacturer has now hit the
three-door coupe production targets for the
2017 WRC homologation and Nandan is happy
that the lower drag characteristics deriving
from the smaller frontal area of this model
will have significant advantages.
Nandan does have some reservations about
the new rules, though. ‘Yes, the cars will look a
little bit more fancy, but for me the worst thing
is the increase of power – I would not have
done it. The cars are quick enough now. I would
have given them more torque [Maximum boost
pressure is retained at 2.5bar absolute; therefore
torque output will be affected minimally] to
have a bit more of a spectacular impression, but
the power I would not have touched. I think it’s
too much – especially now that the rallies are
much faster than before, because all the stages,
if you have a look, are a lot faster.’
Maximum allowed WRC hydraulic pressure
is now 120bar, and providing the required
pressure to operate the active centre differential
in the Hyundai’s 2017 transmission when
fitted to the 2016 ‘mule’ i20 WRC has not been
difficult, Nandan says. ‘[The hydraulic system]
is quite similar to what we have here [in the
2016 car]. We have already a hydraulic block
with two electro-valves for the gear change
and one for the rear [disengage] clutch; so now
[in 2017 spec] there is no rear clutch, but there
is a centre diff. It will be modified [to cater for
greater hydraulic pressure], but it’s nothing. It’s
something we have already tested.’
Before Rally Portugal the 2017 i20 WRC mule
had already covered some 1000 test kilometres,
adequate when considered simply as a vehicle
to test components. But has Nandan formed any
opinion on rival 2017 WRCs? ‘I’ve had a look at
the videos. Yeah, okay, you can see things, but
for sure it is not the final specification; especially
in bodywork, because the regulation is not
final, there’s still the side impact devices to be
defined. It could change a lots of things, but
yes it gives some ideas. It’s always interesting to
have a look at what the others are doing. But I
think that for everybody that is now running
the [2017] car, for sure it is not the same as their
final spec will be,’ Nandan says.
Citroen’s sabbatical
Another varied approach to the 2017 WRC is
the considered tactics of Citroen Racing, which
is taking a sabbatical from the WRC this year,
while PH Sport runs DS3 WRCs under the Abu
Dhabi Total World Rally Team banner. This year is
also the last time Citroen will contest the World
Touring Car Championship, which leaves 2017
free for an all-out WRC onslaught.
Based on a yet to be launched new C3 road
car, the WRC version had its first shakedown test
in early April, driven by Alexandre Bengue on
the small tarmac track next to Citroen Racing’s
Satory, Versailles site. The car was then tested on
rocky gravel by Chris Meeke, and then by Craig
Breen, without major problems. After the tests,
and with a broad grin, Meeke said: ‘The potential
of our new World Rally Car is incredible.’
Meeke then put more testing miles into
the C3 WRC in Portugal. Conditions were very
mixed, with some rain, hail and fog joining the
occasional sunshine. Component lifing was
part of these tests, together with performance
and crew comfort development. Citroen Racing
technical director Laurent Fregosi said: ‘We were
actually quite pleased to have these variable
conditions because they meant we could test
different set-ups and assess how the bodywork
stood up to being loaded with mud.’
The team has worked on the 2017 WRC
project for over a year now, from first design
stroke to built components, assemblies and
car. A current priority is to improve access to
components likely to be replaced in service.
One advantage for Citroen Racing is that
the Global engine in its C-Elisee WTCC racers is
similar to that chosen for its 2017 WRC, and it
has run with a 36mm diameter inlet restrictor
from the beginning. So the team has a good
working knowledge of the similarly restricted
engine in the 2017 World Rally Car. ‘The car
immediately possessed the same power level
as we’ll see next year. We have also tested the
latest suspension systems,’ Fregosi said.
A further bonus of the WTCC racing
programme is the team’s increased knowledge
and experience in aerodynamics, team director
Yves Matton explains: ‘Before we had virtually
no real experience in aerodynamics. It is now a
field in which we have genuine expertise.’
Adopting a just-in-time approach to account
for long lead-time items, assembly of the first
prototype was completed in under a month.
Data analysis from the tests is under way to
hone the specification and a second, tarmac,
test car was under build at the time of writing.
Chassis, engine, transmission and aerodynamic
developments will continue apace until
homologation for the 2017 Monte Carlo Rally:
‘We’ve only just begun the journey,’ Fregosi says,
adding: ‘That point [homologation] seems so far
away, and yet it’ll be here before we know it.’
It’s a serious approach, then, from the French
team, running the test 2017 C3 WRCs before
the new C3 road cars hit showrooms, which is
expected in August. And it’s an approach that
the M-Sport team would love to share. But
currently this seems unlikely.
‘The potential of our
new World Rally Car
is quite incredible’
Ford’s tight deadline
The Cumbria, UK-based M-Sport squad is
determined to be at the 2017 Monte Carlo
Rally with a new World Rally Car, although
team insiders rate the timing as tight. Some
work on the new car has begun, with the main
developments due to commence in early June,
and M-Sport is expected to have the new
mechanical components ready for testing in a
current Ford Fiesta WRC bodyshell in July.
A potential difficulty for the M-Sport team
is that a totally different new Fiesta road car is
imminent. The team does not have a physical
example of the new road car yet, and there are
two possible launch dates mooted, but none
decided. ‘It’s not a facelift; it’s a completely new
car,’ says M-Sport managing director Malcolm
Wilson. ‘The wheelbase is about the same and
we have the old [current] base to work on; that’s
how we can do it. Some of the things associated
with the new bodyshell will be different, but
the actual geometry – all the CAD data of the
chassis – is the same, which means we can
basically modify the current car to the new car.
I’m not concerned; the main thing is running the
[new] mechanical components, which we will
be doing from July onwards.’
There will be changes to the engine, too:
a different cylinder head, a different turbo,
perhaps slightly different pistons, a modified oil
pump, and much of the ancillary items, but the
cylinder block and crankshaft will remain the
same as in M-Sport’s 2016 engine. The team’s
Focus RS WRC had a Ricardo transmission and
the same specialist is supplying the gearbox and
centre differential assembly, and front and rear
diffs, for the 2017 Fiesta WRC.
While Wilson confirms the arrival of the
all-new Fiesta road car will restrict when his
team can launch the 2017 WRC version, he is
still adamant that the car will be ready in time:
‘The plan is to be in Monte Carlo. I’m not that
worried; we’ve enough experience in M-Sport.
We’ve just done a [Focus] rallycross car in six
months from start to finish, that’s as quick as
anything going straight out of the box, so I’m
not that concerned,’ Wilson says.
We will have to wait until Monte Carlo to
find out whether his confidence is justified.
A great many other questions about WRC
2017 will be answered there, too.
The aggressive stance of the 2017 WRC cars is clear in this pic of
the VW Polo development car, but the bodies of the new cars might
yet look a little different as new safety regs have yet to be finalised
Hyundai Motorsport head Michel Nandan says that enough threedoor new Hyundai i20s have now been built for the road for it to be
homologated, and the team will use it for its 2017 WRC base car
M-Sport boss Malcolm Wilson says he is not worried that the new
Fiesta on which its 2017 WRC car is to be based has not yet been
launched and he is confident the new car will make Monte Carlo
CUTTING
TECHNOLOGY
SUBSCRIBE TO THE WORLD’S LEADING
MOTORSPORT TECHNOLOGY MAGAZINE
®
THE
XTREME IN RACECAR
Racecar Engineer
ing
spor
Leading-Edge Motor
PLUMBING
1990
t Technology Since
THE
XTREME IN RACECAR
Leading-Edge Motor
spor
7
Written by engineers
and professionals
within the industry
®
PLUMBING
t Technology Since
1990
Volume 26
No 7 • www.raceca
r-engineering.com
• UK £5.95 • US
$14.50
06
ans
Keep pace with news,
products, technological
developments
and testing
04
7709 61 109 1
July 2016 • Vol 26
$14.50
9
UK £5.95 • US
gineering.com •
6 • www.racecar-en
oyoLtea TMS050
No
June 2016 • Vol 26
F1 regulations 2017
Audi R18 Porsche’s
Mezger engine
e the fight
an this all-new car takt Le Mans?
Porsche and Audi a
2016
July 2016
Full analysis
of Audi’s newar wiRng18
aerodynamics
Re
WTCC
olvo returns to
We investigate new po
we
unit rules and cockpit saf r
ety
Cover_MBAC.indd
3
bac.indd 3
(saving 30% on the cover price)
of the
Uncovering the secrets er unit
Super GT non-hybrid pow
brid efficiency Mezge
r engine
Optimising ele
ctrified
power trains in LMP1
USA - $99.95
Honda NRE engine
26/04/2016 11:14
Porsche’s most succes
sfu
Le Mans engine exami l
ned
(saving over $74)
Rest of World - $64.95
07
July_Cover_06_m
UK - £49.95
9 770961 10
9104
es
Simon McBeath continu
r is
ow Swedish manufacture S60 definitive CFD airflow study
its
h 2017
wit1
rlda
woul
therm
king onFo
Hy
Covering F1,
Le Mans, FIA and
Super GT, BTCC,
Indycar, Formula
Student and more
With FREE POSTAGE
24/05/2016 15:26
SUBSCRIBE HERE
G
N
I
R
E
E
N
I
G
N
E
R
A
C
E
C
A
R
h
t
i
w
L
A
GO DIGIT
ON YOUR TABLET
Subscribe to the digital edition
for fast and easy access to Racecar
Engineering anytime, anywhere.
Available on:
VISIT OUR WEBSITE
www.racecar-engineering.com
All the breaking news, technical
developments, race results and
rule changes as they happen.
Have the latest developments delivered direct to your inbox by signing up to our email newsletter,
and keep up to date with breaking news and commentary as it happens by following us
on social media.
Subscribe to our newsletter
www.racecar-engineering.com/sign-up-to-our-email-newsletter/
/RacecarEngineering
@RacecarEngineer
+Racecar Engineering

World ofrally - The Chelsea Magazine Company

Transcription

Similar documents

Well here we are in Fontainebleau State Park Mandeville, La. Oh

REACH World TB day - Partnership for TB Care and Control in India

Co-driving

Ariel Owners, Riders and Enthusiasts!

Angel City Rally - motorsportamerica.com

In the m iddle of July the Autoglym Rally is run on - PR

We look forward to seeing you on June 4th., 2016

What do Margaret Cho, Bill Nye, and Johnny Depp

American Iron Magazine: Top 10 Motorcycle Rallies of the Summer

WKYS (FM) - Great 98 WRC