FUEL PUMP TECH

FUEL PUMP TECH
FUEL PUMP SIZING
Everyone knows that "You can't make horsepower without fuel." Pump sizing is relatively easy. If your engines output is to be
increased 75%, then it's fuel pump output must be capable of supplying 75% more fuel. 75% more power - 75% more fuel. However,
the 75% increase in HP will occur only at WOT (wide open throttle) and the upper rpm range. The BOOST-A-PUMP® is the perfect
solution and match as it increases the fuel supply ONLY at WOT. We supply a switch to activate the pump at "0" vacuum (naturally
aspirated) or 3 psi (turbocharged or supercharged). At part throttle and cruise when the engine consumes relatively little fuel, the
BOOST-A-PUMP® is not activated. Therein is the basic problem with larger "full time" in line or in tank pumps. They are noisy and
"active" at all engine speeds and loads pumping all that unused fuel back to the tank - and heating it in the process. Any flow of liquid
through piping creates friction (heat). The higher the flow, the greater the friction (heat build up). Remember that gas begins to boil at
95 degrees causing reduced fuel octane and pump efficiency. Race gas boils at 87°. One manufacturer even offers a voltage
REDUCER to lower fuel temp and noise. What does that tell you? That's why professional drag racers all use cool cans to cool and
stabilize their fuel supply. This is an example of where larger and more i.e. bigger in tank pumps aren't better.
ACTUAL TEST ON FUEL PRESSURE BEFORE AND AFTER THE KENNE BELL BOOST-A-PUMP
60
325
AFTER BOOST-A-PUMP
50
300L 17.5 VOLTS
300
50 PSI
275
30
35 PSI
BEFORE BOOST-A-PUMP
(pressure dropping off causes lean condition,
poor performance, possible engine damage)
20
FLOW (ltrs/hr.)
FUEL PSI
250
40
225
200
171L 12 VOLTS
175
150
125
10
100
0
75
2000
2500
3000
3500
4000
4500
5000
RPM
30
40
50
60
PRESSURE (lbs/sq.in.)
"The BOOST-A-PUMP®” is the best thing to ever happen to a stock fuel pump.”Jim Bell, President
FUEL PRESSURE DROP OFF
Get a fuel gauge. You can't tell what your fuel system is
doing without one. Fuel pressure "drop off" can be a
serious and expensive problem. If a fuel pump is
incapable of supplying an adequate volume at WOT,
then the pressure will drop off at the higher rpm levels.
PUMP CURVES (STOCK vs. + 75% BOOST-A-PUMP®)
How many times have we heard "I've got plenty of
pressure but I need more volume." Wrong analogy. If the
desired pressure is there, don't increase or even worry
about volume. Pressure is everything to the fuel
injectors.
10 psi of fuel pressure will lean or richen an engine 8%. 5
psi is 4%. 20 psi is 16% etc. The BOOST-A-PUMP® is
your best guarantee against fuel pressure drop off. And
since the BOOST-A-PUMP® is also a voltage regulator,
it automatically adjusts the pre-set voltage to the pump
when the accessories lower the input voltage - or even if
the alternator fails! In other words, it's also a voltage
regulator/fuel regulator.
.
The two pump flow curves above illustrate the operating
principle of the BOOST-A-PUMP®. The ingenious
device merely increases the flow (volume) of any pump
up to 100% by raising the voltage supply to the pump. A
mere 1 volt variance will affect pump output up to a
whopping 17%.
Study the graph and you'll notice that as pressure
increases, flow decreases - and as pressure decreases,
flow increases. To determine the flow and pressure of any
pump, one must look at the pump's "curve." All pump
manufacturers rate their pumps this way.
Again, the BOOST-A-PUMP® merely spins the pump
faster allowing it to produce more fuel. No new expensive
billet hats, supply and return lines, valves, regulators,
relays, wiring, connectors and fittings are required. And
no driveability issues.
FLOW SENSOR
CHASSIS DYNO - FUEL FLOW DYNO INTERFACE
Mounting a fuel flow sensor in the fuel line at the fuel rails gives a true reading of how much fuel the dyno engine is using. Since our
Fuel Flow Dyno is located adjacent to our chassis dyno, we are able to actually “plug” our fuel flow sensor on a vehicle directly into
the Fuel Flow Dyno and compare vehicle to same fuel system on Fuel Flow Dyno.
PUMP VOLTAGE COMPARISONS ON KENNE BELL FUEL FLOW DYNO
There’s much more to pump efficiency than advertised numbers. Pump performance and flow is TOTALLY DEPENDENT ON
VOLTAGE, which varies considerably. Wiring accessories (lights, stereo, ignition, alternator - and fuel pump) require current to
operate and wiring to transmit the current. Voltage losses in ANY wiring network lowers the available voltage (energy) to the pump. A
single (1 volt) drop in pump voltage is 7-17% LESS FLOW. That can destroy your engine. The BOOST-A-PUMP® incorporates a
built in VOLTAGE REGULATOR that compensates for pump voltage (flow) variations. Above are 3 different pump input voltages
(10.5, 11.5 and 12.5). Again, a couple of volts (12.5-10.5) loss to the pump can easily be a 25% flow drop. Note how the BOOST-APUMP® “regulates” it’s output voltage to the pump within one percent (13.65-13.67) - far better than 25%. That means consistent
fuel delivery regardless of voltage.
COMMON FUEL CONVERSION FACTORS
VOLTAGE vs FLOW
(FLOW AND PRESSURE)
TO GO FROM
WALBRO GSS340 @ 60 PSI
VOLTAGE
@ PUMP FLOW (L)
BOOST-A-PUMP®
BOOST-A-PUMP®
BOOST-A-PUMP®
BOOST-A-PUMP®
BOOST-A-PUMP®
21.0
17.5
13.5
12.0
11.0
440
351
257
206
171
MULTIPLY BY
TO GET
Litres
0.264
Gallons
Gallons
3.785
Litres
Litres of fuel
1.660
Pounds of fuel
Pounds of fuel
0.600
Litres of fuel
Gallons of fuel
6.300
Pounds of fuel
Grams per sec.
7.930
Gallons per hour
CC per min.
0.016
Gallons per hour
Inches HG
1.133
Inches water (H20)
Pounds per sq. in.
2.310
Feet of water (H20)
Pounds per sq. in.
2.030
Inches mercury (Hg)
PUMP TESTING
Pumps are tested individually, as an assembly (canister), hat, tubing, fittings, relief valves etc. and as part of the complete fuel
system with fuel lines to determine just how much HP they will support with and without the BOOST-A-PUMP®.
NOTE: Late Ford, Dodge, GM etc. pumps are an integral part of the canister and cannot be disassembled,
replaced or upgraded without destroying the assembly.
78-400L
‘07 UP DODGE, CHRYSLER
2V ‘96-’04 MUSTANG
‘11 UP 5.0 MUSTANG, BOSS 302
SAME PUMP )2( USED IN ‘13 UP SHELBY GT500
‘10 CAMARO
JPC DUAL / TRIPLE RETURNLESS SYSTEM
BILLET HAT
AEROMOTIVE SINGLE 1000
FUEL SYSTEM BASICS
A Basic Overview of Fuel Systems
Kenne Bell has long been recognized as a leader in fuel system engineering and technology. The following should help
you understand some fuel system basics. For our data and information, we rely on our highly sophisticated FFB (fuel flow
bench) to test not only pumps, but fuel lines, fittings, filters, fuel rails, injector and complete vehicle fuel systems. The
BOOST-A-PUMP®,the most successful fuel system product ever, continues to be the NUMBER ONE choice for
increasing fuel delivery. It has been used exclusively on Kenne Bell Supercharger Kits, including the dual pump ultra
powerful Shelby GT500/Super Snake 800HP kits, Dodge Hemi (up to 900HP), 2010 up Camaros (up to 900HP, one of the
“Fastest Production Sport Cars in the World” (the 806HP/242MPH Koeniggsegg CCR), the Lingenfelter 950HP Corvettes
and the 1000+HP 2013 Shelby GT500. All pumps are tested on the Kenne Bell in house computerized FFB. Note: When
viewing our pump flow data, it’s important to keep the following hydraulic basics in mind.
 Tests were run at 60 psi. Pump flow increases as pressure decreases and decreases as pump pressure increases.
Example: As compared to 60 psi, flow will be approx. 15% higher at 40 psi and 15% lower at 80 psi. Remember, larger
lower pressure injectors may supply more fuel than the smaller higher pressure injectors IF there is sufficient pump
capacity.
‚ Any increase in boost pressure must be deducted from the injector pressure rating as the manifold boost “resists” the
flow/pressure of the injectors. The fuel pressure MUST be increased to compensate for higher boost. 10 psi higher boost
and fuel pressure LOWERS pump flow 7%. Example: Our Shelby GT500 makes 801HP at 23 psi boost and 83 psi “rail”
pressure to net 60 psi Delta or injector pressure. And it’s exactly why boosted vehicles need HIGHER FLOW RATINGS
than naturally aspirated engine pumps and why it’s difficult to “rate” pumps. Lower pressure/higher flow injectors are also
a good solution. Be sure your tuner understands this. We refer to it as Delta pressure.
ƒ Air fuel ratio also affects pump flow. Example: Richening AF ratio 10% from 12.5 to 11.5 increases pump flow 10%.
„ A 10 psi reduction in fuel pressure affects AF ratio 8%.
… AF ratio similarly affects pump duty cycle in non return systems.
† Fuel supply lines and fuel rails are often upgraded unnecessarily without sound fuel flow analysis. At Kenne Bell, we
flow test fuel pumps, fuel lines AND rails on our FFB and the vehicle on the dyno. They’re adjacent to each other.
Example: There’s only a 7 psi pressure drop from tank to rails at 700RWHP with an ‘03 Cobra. Who else has performed
this test? The 7 psi isn’t an issue if 1. the pressure is adequate or 2. the pressure is not dropping off. Is it worth installing a
$1500 fuel system for a 6, 5, 4 or ? psi reduction?
FUEL SYSTEMS AREN’T THAT DIFFICULT - WITH A BOOST-A-PUMP™
A mere 3 psi drop at 600HP is certainly not an issue with a Cobra. And our ‘07 Shelby makes 801HP with the STOCK lines
and pumps and the Dual BOOST-A-PUMP® at 60 psi Delta (83 psi rail) and 96% duty cycle. At 40 psi Delta (63 rail) and
larger injectors, the pump flow will increase a whopping 15% which will support another 15%HP or 920HP. Get the
picture? 801 x 1.15% = 920HP. Rest assured, a larger fuel line or more/larger pumps WILL NOT MAKE MORE HP unless
the pressure loss in the supply line is “excessive.” The optional 20V BOOST-A-PUMP® increases pump flow and HP (68% less duty cycle) up to 1000HP. But what is “excessive?” 3, 5, 10 psi? There is up to 10 psi loss in some of the Billet (2
and 3 pump) hats. Think about that. It’s not just pressure or flow. It’s knowing the facts from fiction and understanding the
entire fuel system. A BOOST-A-PUMP® makes it easy, inexpensive and reliable. If 6 psi feed line loss is a problem, why
isn’t the 10 psi loss in a $1500 billet hat system?
FREQUENTLY ASKED QUESTIONS
HOW EFFICIENT IS THE BOOST-A-PUMP®? DO I NEED BIGGER AFTERMARKET PUMPS?
No one wants to knowingly short change their engine on fuel. OEM style pumps, particularly with the BOOST-A-PUMP®,pump
enough fuel for 99% of the applications, street or race. If one takes the time to look at the REAL test data on fuel pumps, it clearly
indicates that the stock OEM pumps are over designed approx. 30%. Clearly enough fuel for a stock engine - or up to 30% more HP.
Add this 30% to the 75-100% offered by the BOOST-A-PUMP® and you have a whopping 100% additional fuel capacity vs. stock.
That will support a LOT of HP. Below are some examples:
SAMPLE PUMP COMPARISON OVERVIEW (12, 17.5, 20V)
SINGLE & DUAL WITH & WITHOUT BOOST-A-PUMP®
PUMPS
APPLICATION
12V
*DUAL
TRIPLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SHELBY GT 500
SHELBY GT 500
SHELBY GT 500
MUSTANG 5.0 ‘11 UP
MUSTANG ‘05-’10
T1/WALBRO GSS340
HEMI 5.7, 6.1, 6.4,
CAMARO ‘10 UP
T1/WALBRO GSS340
AEROMOTIVE STEALTH
WALBRO F9000267
AEROMOTIVE 1000
290L
435L
189L
217L
148L
206L
181L
149L
260L
242L
320L
275L
17.5V
20V
BOOST-A-PUMP™
587L
NA
245L
435L
270L
351L
320L
291L
351L
NA
NA
NA
732L
NA
426L
549L
337L
440L
401L
363L
440L
NA
NA
NA
IMPORTANT
*Flow is for assembly (both pumps and stock hat). Flow is always less
than ratings of 2 single pumps (426x2=852) vs dual assembly (732L).
Look at the actual pump flow of these sample pumps at 12V (pump mfgs. rate their pumps at 12V) and compare the flow to BOOSTA-PUMP® flow at 17.5V and 20V. With wiring losses, accessories (stereo, ignition, lights) we are assuming a pump(s) sees about
12V at WOT under max load. If installing a complete new system (wiring, connectors, lines, pumps, etc) you would probably shoot for
13.5 volts under max load. The advantage of the BOOST-A-PUMP® is it “regulates” voltage and GUARANTEES 17.5 or 20V
regardless of the pumps input voltage (12, 12.5, 13, etc.) in a stock vehicle. The flow gains from the guaranteed voltage (17.5 or 20)
can be seen in the chart. It’s hard to beat a BOOST-A-PUMP® / stock system unless your application demands a complete new ultra
high HP system.
ADDING ANOTHER PUMP (DUAL OR TRIPLE) IN A BILLET HAT
Sounds like a good idea, but not what you expect. A Shelby stock “dual pump” assembly is 290L. Add a BOOST-A-PUMP® and it’s
587 (17.5V) - 732 (20V). See why the KB BOOST-A-PUMP® is so popular? Compare that to a 3 pump billet hat system with a max
flow of only 435L (290+145). Note how adding another Shelby GT 500 pump (189L) does NOT equal (378) but instead 290L. That’s
typical. Fact is pump capacity is off by 23% because of the losses in the lines and fittings that connect the pumps. Up to 23% loss also
exists in the “billet hat” systems we tested because the fuel is routed horizontally through undersized restrictive machined passages
in the billet housing itself. Note the TRIPLE BILLET HAT is only 435L @ 12V vs 732L for the stock dual BOOST-A-PUMP® @ 732L.
Oops.
Assuming your pump(s) are currently seeing 12V at WOT, the chart gives you the actual flow increases from the BOOST-A-PUMP®
street (17.5V and competition (20V). The Aeromotive 1000 and other “billet hat” assemblies is a complete new in tank unit that
requires expensive all new plumbing, wiring and converting your car to a returnless system. It pumps 275L at 12V. The best scenario
would be to somehow get a “full” 13.5 alternator voltage with no wiring losses. Flow at 13.5=450L. Kenne Bell even offers a MEGA
BOOST-A-PUMP® to increase the flow of these pumps. In any case, “dual” and “triple” billet pump kits appear to be a little overrated.
IS THE BOOST-A-PUMP™ A SAFE PROVEN CONCEPT?
We think so. Kenne Bell introduced the BOOST-A-PUMP® in 1995. Today it is standard equipment on nearly all our supercharger
kits. It is the most proven, reliable and efficient method of increasing fuel delivery. Also, it is safe and reasonably priced with virtually
“0” failures. Ford engineers recommend it. Other supercharger kit manufacturers have abandoned their “larger” pumps and now
offer the BOOST-A-PUMP®. Have you ever tried to adapt one of the larger 340L or 400L pumps to a Mustang 5.0, Dodge Hemi, or
Camaro stock pump assembly? What a nightmare of custom plumbing and wiring. And you destroy the canister. The BOOST-APUMP® actually INCREASES pump life of any new returnless style pump. There has not been a single case of a Kenne Bell BOOSTA-PUMP® damaging a fuel pump. And it is responsible for supplying enough fuel for a stock 500HP Shelby GT 500 to develop
825HP - with NO OTHER CHANGES to the stock fuel system. Still believe you need larger lines, rails and pumps?
WHAT IS THE BOOST-A-PUMP® PRINCIPLE OF OPERATION?
It’s a simple, proven Kenne Bell concept, developed in 1995, that does not require larger pumps, fuel lines, rails and expensive
plumbing. “Bigger” and “more” pumps is not always better. Much like the stock Ford returnless systems, that uses voltage to LOWER
pump output from 100%-0% duty cycle, the BOOST-A-PUMP® merely RAISES voltage from 12V-17.5 or 12V-20V and pump output
up to 100%. Varying pump flow by voltage is precisely how the Ford “returnless” systems operate. The voltage is constantly adjusting
up or down on the input side of the FPDM. The FPDM then “pulses” the pump to maintain the commanded pressure based on the
Delta pressure on the fuel rail. When the pump voltage at 13V can no longer supply enough pressure, the BOOST-A-PUMP® will
increase the pump voltage (pressure and flow) up to 17.5V. The BOOST-A-PUMP® merely supplies the pumps or FPDM(s) with the
power they need where the stock system leaves off.
TESTIMONIALS
Adam Montaque, ST MOTORSPORTS 825RWHP “World’s Fastest PD Street Legal 3V 4.6 Mustang w/no NOS.” 9.50/142. Street
Dual BOOST-A-PUMP® w/Ford #M907GT05 drop in dual pumps. Stock fuel lines and rails, 825RWHP, 60lb, 92% duty cycle.
Adam’s back to back tests with Competition Dual BOOST-A-PUMP® - no other changes - lowered pumps duty cycle to a mere 62%!
A whopping 32% reduction. That leaves lots of room to grow. (+200HP) with other mods such as NOS, stroker kits, bigger cams, etc.
Adam Montaque, ST Motorsports
“I couldn’t believe the fuel this new Competition system produces! The numbers don’t lie. I could run in the 8’s with this set up and NOS
with no other changes. This is way more fuel than 99% of my customers will ever need! I also use the BOOST-A-PUMP® on my 6.1
Challenger (765RWHP) and 6.2 Camaro (801RWHP) with stock fuel system.”
Jon Lund, Jon Lund Racing
“I recently tuned a Shelby GT500 with Kenne Bell 3.6LC. It developed 902HP at 88% duty cycle using only Competition BOOST-A-PUMP®
and 23 psi boost. That leaves 12% safety factor. The car had stock Shelby pumps, fuel lines and rails with 80lb injectors.”
IS A SINGLE BOOST-A-PUMP® SUFFICIENT?
Of course it is. Pump FLOW is what is paramount. It makes no difference if it’s single or dual, domestic or import, or car or truck. The
injectors only care if there is adequate fuel delivery. For example, the 20V Competition BOOST-A-PUMP® will support up to
765RWHP on the Dodge/Chrysler 5.7, 6.1 Hemi, 800RWHP on the Camaro, 732RWHP on the 2011 Ford Mustang 5.0 and
854RWHP for the Boss 302. This is typically beyond the safe HP limits of these engines. If the pump delivers enough L per HP, all is
well. Note: Installing “dual pumps” in a vehicle that was produced with a single pump will typically create wiring, routing and capacity
issues. Best bet is to run new wiring, plumbing etc. Very expensive, but necessary.
HOW MUCH HP WILL THE BOOST-A-PUMP® SUPPORT? (See Fuel & HP Estimator)
The BOOST-A-PUMP® will increase the output of any 12V pump up to 75% @ 17.5V and 100% @ 21V (competition). For a specific
pump flow, check out our “Fuel and HP Estimator.” This is the most complete pump performance guide ever compiled. All testing was
performed on the Kenne Bell Fuel Flow Dyno.
SHOULD I REPLACE MY PUMP WITH A LARGER PUMP OR THE BOOST-A-PUMP®?
Both approaches will work, but there’s more labor involved in removing the pump from the tank. And unless the pump is part of a “kit”
with all the wiring, hoses and fittings, adaption and fabrication can be a serious issue. If the pump upgrade is adequate for your HP,
you may not need a BOOST-A-PUMP®.
DO I NEED TO REPLACE ANY WIRING?
No. Re-wiring and relays are what we avoid with the BOOST-A-PUMP®. Some kits may require a larger fuse (included in kit).
FUEL RAILS?
Our Fuel Flow Dyno can test fuel rails individually or collectively for fuel pressure loss. Stock rails will support 1000HP on our tests.
We use billet rails on our kits only if there is a fitment issue with the stock rails.
DOES THE BOOST-A-PUMP® INCREASE FUEL HEATING?
No. It is only activated when the engine demands more fuel. However, return systems run at full speed all the time and are notorious
for “recirculating” and heating fuel under idle, part throttle and cruise. We can get 30° running a return style on our Fuel Flow Dyno
under ideal “in lab” conditions. Remember, fuel boils at 97°. Vapor lock can occur when the fuel starts boiling.
CAN I RUN THE BOOST-A-PUMP® FULL TIME?
Absolutely not. Do not let anyone talk you into this. There is no reason to pump 50-100% more fuel at idle and cruise where your
engine is only using 2-10% of the stock pump capacity. Note: Replacing the stock pump(s) with larger HIGHER AMP pump(s) can
and will require re-wiring.
WHEN DO I NEED TO LOOK AT WIRING SIZE?
When installing ANY larger/higher amperage than stock fuel pump(s). Any pump that produces more fuel will use more current
(amps) and tax the stock wiring. The BOOST-A-PUMP® is designed to work with stock wiring. Only a larger fuse is necessary.
NITROUS?
NOS needs additional fuel. The big question is always “Is my stock fuel system adequate?” The BOOST-A-PUMP® is an ideal easy
to install economical approach to increasing fuel supply 75-100% on demand. If using NOS with a supercharger kit, verify there is
sufficient fuel for both.
WHAT ABOUT NOISE?
Again, the BOOST-A-PUMP® is only activated at WOT. You’ll never hear the increased pump speed under idle or cruise.
I PLAN ON RUNNING E85 BECAUSE OF THE HIGHER OCTANE. ANY PROBLEMS?
Not with the BOOST-A-PUMP®.Be sure your pumps and ALL fuel system components - including the pump and in tank wire
connections are E85 compatible. The TI 90000267 is the only E85 compatible aftermarket pump we are aware of. Alcohol is highly
corrosive. E85 requires 30% more fuel volume. The BOOST-A-PUMP® is able to supply up to 100% more fuel with a one wire hook
up.
WHAT ABOUT SAFETY FACTORS?
When the ACTUAL pump flow is unknown because of voltage variations (voltage/flow of pump), one approach is to “guess” at it - or
warn that the pump may not develop the advertised ratings. Ford recommends users deduct 10% from the advertised pump rating.
The regulator in the Kenne Bell BOOST-A-PUMP® guarantees the correct 17.5 or 20V supply. But then there is the “losses” in the
hat, lines and fittings - AND FROM BOOST. Everyone seems to overlook boost. Use the “Kenne Bell Fuel & HP Estimator.”
WHAT IS A “RETURNLESS SYSTEM?”
See “BOOST-A-PUMP® Theory Explained.” Returnless systems are now used by all the OEM’s. There are two types - pump
modulating and internal pump regulation. Fuel heating/boiling, fuel octane loss and emissions are all synonymous with old style
“return systems.”
IS IT PRACTICAL TO REPLACE AND UPGRADE THE PUMP IN THE NEW STYLE CANISTERS AS USED IN THE ‘11 UP
MUSTANG, ‘10 UP CAMARO, ‘07 UP DODGES, ETC?
No. Those days are over. These plastic assemblies cannot be disassembled without destroying them. We have analyzed all of them.
And if you did break one open, you would quickly see the complexity of replacing a pump even if one did somehow fit and hook up to
the tubing and wiring. Our advice is to use the BOOST-A-PUMP® concept or remove the canister and engineer an entirely new
system.
DOES BOOST AFFECT MY FUEL REQUIREMENTS?
Absolutely. But rarely is boost ever considered when calculating fuel requirements. Example: 10 psi of boost reduces injector flow by
10 psi. Boost in the manifold forces fuel back into the injector.
YOUR COMPETITION MAKES SOME WILD CLAIMS ABOUT “DELIVERY”, “NOISE” & “PAUSING”
The BOOST-A-PUMP® doesn’t “DELIVER”, they claim. Really? Proven and tested up to +100% (they claim 80%) since 1996 and
virtually “0” failures for the last 16 years. Notice our competition conveniently fails to mention that theirs operates at a whopping 25°
hotter than a KB. Oops. So, it is not recommended for underhood mounting and must be located in the car or trunk. Could that issue
be related to lower grade more heat and moisture sensitive components and reliability. And they think you should pay more money
for this? We quote from their Instruction Manual: “The unit must be mounted inside the vehicle cabin (under a seat) or in the trunk.
Install the unit so it does not come into contact with water or extreme engine heat (+250°).” Last time we looked, there are a LOT of
electrical components under the hood . . . like the Kenne Bell BOOST-A-PUMP® since 1996 . . . that can tolerate “extreme” ordinary
250° underhood heat. Sounds UNRELIABLE and under-designed to us.
“NOISE” VIDEO FROM COMPETITION
Why test and video ANY voltage booster with a RESISTOR instead of the PUMP to show “noise.” Resistors don’t pump fuel. The
Kenne Bell BOOST-A-PUMP® was designed to run pumps, not resistors. So, one should measure the INDUCTIVE load from the
pump and not the RESISTIVE load from a resistor. Notice their own DC meter didn’t measure any of this “noise” they speak of.
Perhaps they should try dunking them both in a bucket of water or under the hood for 8 hours and see how they perform under real
world conditions - or get a Fuel Flow Bench and do some meaningful testing. We sure tested theirs on our bench.
“PAUSING”
Finally, they recommend “pausing” or “delaying” the BOOST-A-PUMP® activation at boost. Hmm? Isn’t that where your engine
NEEDS THE FUEL TO PREVENT DETONATION AND ENGINE DAMAGE? Why starve your engine for fuel when it needs it most in boost. Leave the Kenne Bell as is and activate it at 3 psi as per our design.
RATING FUEL SYSTEMS
HOW TRANSMISSIONS & SUPERCHARGERS AFFECT FUEL DEMAND
Why do Kenne Bell Fuel System, HP Ratings and Recommendations vary between like vehicles? All else equal, we all know that a
modified higher HP engine demands more fuel.
PARASITIC LOSSES
But few consider the added 35HP necessary to drive an automatic trans vs. a manual. The water pump, alternator, PS, PB and AC
also depend on the engine to drive them, but they are a constant. And there are other factors.
BSFC
Many use the BSFC to “estimate” pump or fuel efficiency. First, using .5 for NA and .6 or .65 BSFC for supercharged/turbocharged
applications is NOT accurate as it does not address the following:
 BOOST - How much? 5, 10, 15, 20, 25 or 30. Boost affects injector flow. Subtract boost from the injector psi rating and use the
lower pressure injector flow rate. Example: 60 psi - 80 lbs/hr vs. 10 psi boost or 50 psi = 73 lbs hr.
NEW PRESSURE
OLD PRESSURE x OLD FLOW = 73 LBS/HR (new flow)
‚ LINE LOSS - Typically only 6.5 psi loss at 800HP and 8,5 psi loss at 1000HP. Not a big deal.
ƒ PUMP EFFICIENCY - Is the pump operating at 12 or 13.5V? Is the pump in a canister? 1 or 2 pumps (2 pumps typically lose 22%
total flow when paired in a canister and more if 3 pumps).
„ RWHP or EHP - There’s a 15% difference in the HP “rating.” Which is it?
… PARASITIC LOSS - You may find this one particularly interesting reading. Supercharger efficiency (power consumption/parasitic
loss), gears, water pump, etc. all consume engine HP and USE FUEL even though dyno HP reads less. Engine still consumes same
amount of fuel. The Kenne Bell “Fuel & Horsepower Estimator” takes into account these factors and will even determine the injector
flow required.
DO I NEED A LARGER FUEL LINE?
Big misconception. We have thousands of BOOST-A-PUMP® customers making BIG HP numbers with stock fuel lines and rails.
Here’s the proof of how easy and economical it is to support 800-1000+HP. This will give you some idea of what the pressure loss
would be at the various fuel flow/HP numbers. What’s important is that a BOOST-A-PUMP® on a stock pump produces a LOT of fuel
WITHOUT LARGER fuel lines. Even 8.5 psi loss in a stock line at 318L (1000HP) is not a big concern. 248L is 780HP. On the
Shelby’s and earlier Fords (Dodge used same relief valve as 5.0 Mustang) - and Camaros - the ECM can be calibrated to merely
increase the pressure 8.5 psi and compensate totally for the 10 psi loss. So are you sure you need that expensive 2 or 3 pump billet
system with a 2 psi loss instead of 8.5 psi? If 6 psi line loss (8.5-2=6) is a “problem” your fuel system is too marginal to start with. Use
common sense and the facts when deciding on a fuel system.
NOTE: ‘05 up Mustang/Shelby, Dodge Hemi and Camaro use the larger 3/8” supply line shown below.
2011 MUSTANG GT FUEL LINE LOSS TEST
PUMP USED: DUAL WALBRO T1 F9000262
TEST METHOD WITH FITTINGS:
THE STOCK FUEL 3/8 O.D. LINE WAS PURCHASED INCLUDING THE LINE THAT GOES TO
THE RAIL. ONE GAUGE WAS PLACED AT THE ENTRY (FUEL TANK) OF THE LINE, AND
ANOTHER RIGHT AT THE DISCHARGE BACK TO THE RETURN. A THROTTLING VALVE
WAS PLACED AFTER THE LINE BUT BEFORE THE FLOWMETER TO SET LINE PRESSURE.
PUMP PRESSURE WAS SET AT THE ENTRY (FUEL TANK) END OF THE LINE, THEN THE
SECOND GAUGE WAS READ TO DETERMINE THE LOSS.
TEST METHOD W/OUT FITTINGS:
SAME TEST, BUT ALL FITTINGS WERE REMOVED FROM THE LINE, THEN THE SECOND
GAUGE WAS READ TO DETERMINE THE LOSS.
PUMP
PSIG*
PSI DROP
W/ FITTINGS
PSI @ RAIL
FLOW (LPH)
PSI DROP
W/OUT
FITTINGS^
70
6.5
63.5
248
6.0
60
7.5
52.5
281
7.2
50
8.5
41.5
318
7.5
40
10
30
352
8.2
* SET AT ENTRY TO FUEL LINE (TANK END)
^ EXTRAPOLATED DATA
IMPORTANT
“I’m out of fuel. My RWHP estimates say I should have more fuel left” Check out the info below.
SUPERCHARGER FUEL DEMAND VS PARASITIC HP LOSSES
All else equal, a given test engine consumes the same amount of fuel whether it is driving a less efficient supercharger, manual or
automatic trans, lower rear end gears, water pump etc.
It simply “wastes” fuel, HP and vehicle speed driving these power robbing components so the rear wheels see less HP because of
the parasitic losses / power consumption. Even the AC uses more engine HP and fuel but ONLY when the cruise control increases
throttle opening to maintain vehicle speed. More speed = more HP. That’s why there are more efficient superchargers, electric
water pumps, lock up torque converters, under-drive pulleys etc. They all lower this wasted HP to the rear wheels while reducing
fuel consumption.
Again, you never touched the engine itself or altered the fuel delivery (rich or lean) so the fuel consumption by the pump, injectors
and tune are unchanged. And yes, if the HP of the vehicle with the inefficient supercharger is increased 63 HP with headers, cams
etc. to compensate for the more efficient supercharger vehicle, then the fuel system must be able to support this new fuel demand of
+63 HP.
Why this discussion? Because Kenne Bell rates our BOOST A PUMP HP based on 1) Kenne Bell Twin Screw superchargers and 2)
Manual Transmissions. We are the only company that we know of who provides this tech and data for our customers.
Example: Note stock engine was 320HP. Both superchargers consume the same amount of fuel but HP output of KB at same boost
is +35HP. Eaton will then “run out” of fuel delivery at 605HP instead of 640HP because it uses 35 more engine HP to drive it.
STOCK HP
HP / SC
320
605 / EATON
320
640 / KB
DIFFERENCE
PARASITIC LOSS
MAX RELATED FUEL
PUMP FLOW L/HR
AIR FUEL
RATIO
-35
SAME
11.5
-
SAME
11.5
Even if both superchargers produce the same boost and air temps, the less efficient supercharger will use more engine HP to drive
it. And the higher the RPM and boost the wider the HP gap. Note that supercharger power consumption was the same until 420HP.
(See dyno graph).
COMPONENT POWER CONSUMPTION
AUTO VS MANUAL
AUTO VS MANUAL
AUTO VS MANUAL
AUTO VS MANUAL
3.73 VS 3.08
UNDER DRIVE PULLEYS
ELECTRIC WATER PUMP
‘11 UP MUSTANG
‘05 UP DODGE
‘10 UP CAMARO
EATON VS TWIN SCREW & CENTRIGUGAL
GM, FORD, CHRYSLER
GM, FORD, CHRYSLER
GM, FORD, CHRYSLER
*35 LOCK UP
*35 LOCK UP
*45 LOCK UP
15-100HP DEPENDING ON BOOST & RPM
**18 HP
1-2HP / 1000 RPM
8-12 HP & HIGHER FOR 4.10 ETC.
*HP loss with automatic trans. A non lock up converter will be higher depending on stall speed.
**The lower the gear ratio, the higher the HP loss.
A factory type lock up clutch converter is approximately 25 peak HP vs a higher stall “competition” non lock up. We have designed,
sold and experimented with lock up torque converters on turbocharged Buick GN’s and our supercharged vehicles since the 80's,
when the OEM’s first began using them.
Increasing the stock stall speed (converter size or fin angle) AND eliminating the clutch results in more slippage and reduced HP.
Anyone who believes converter slippage / higher stall is beneficial try this: Launch your manual trans car and then....push the clutch
in so it slips 500-1000RPM and see if the car accelerates as fast. Then check your 1/4 mile time slip.
Our recommendation: Stay with the stock stall speed, keep the clutch and let the positive displacement supercharger (Roots or
Twin Screw) supply the additional torque vs lower gas guzzling gears and “slipping” the converter to allow the centrifugal to rev for
more boost. “Slippage”, “HP loss” and “heat” (trans and engine) are NEVER good unless a compensating for the inherent low
torque/RPM/boost disadvantage of a centrifugal or turbo.
SO if you car “runs out” of fuel at a lower than the Kenne Bell advertised HP, regardless of fuel system or manufacturer, you may
want to allow for the 1) Supercharger 2) Transmission and 3) Lower Gear Ratio.
FORD PUMPS
DUAL PUMP FLOW SUMMARY (L/HR, 60 PSI)
BOOST-A-PUMP® vs NO BOOST-A-PUMP®
SHELBY GT 500, SUPER SNAKE, KR, FORD GT, 03 COBRA,
DUAL PUMPS
‘05-’06 FORD GT
’07-’12 SHELBY GT 500
‘13 UP SHELBY GT 500
’03-’04 COBRA (SHELBY PUMPS)
’05 UP MUST GT*
’99-’04 MUST*
‘03-’04 COBRA (STOCK PUMPS)
R = Return style
FUEL
SYSTEM
&
PUMPS
RL-2
RL-2
RL-2
RL-2
RL-2
RL-2
RL-2
RL = Returnless
60 PSI FLOW L/MIN
STOCK
BAP
BAP
12V
17.5V
21V
300
290
380
290
280
290
194
548
587
761
537
530
537
360
750
732
961
732
730
732
483
*KB89064, KB89069-17.5V
FPDM
BOOST-A-PUMP®
TYPE
2
2
2
2
2
2
1
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
SINGLE
PART NO
KB89064-63*
KB89064-63*
KB89064-63*
KB89064-63*
KB89064-63*
KB89064-63*
KB89069-70*
KB89063/KB89070-20V
• ‘03 Cobra w/stock pumps use “Single” BOOST-A-PUMP® part# KB89069. OK to 750HP with 80 lb injectors.
* Ford GT, Ford GT FRP kit #M-9407 GT05 (Dual Shelby GT500 pumps), Shelby GT 500, KR, Super Snake use
“Dual” BOOST-A-PUMP® part# KB89064, KB89064-20. OK to 920HP (17.5V) and 1000HP (20V) with 80 lb.
Kenne Bell BOOST-A-PUMP’s are available in two voltages. Street 17.5V and Competition 20V. Consult
us for recommendations and HP requirements.
‘07-’13 SHELBY GT 500, SUPER SNAKE, KR
The “Dual” BOOST-A-PUMP® module is designed specifically for the new dual pump systems used on the ‘07 up Shelby GT 500,
Super Snake, KR and the Ford GT. It raises the HP capacity from 550 to 800RWHP - with NO OTHER CHANGES - even with stock 52
lb high pressure injectors. Up to 900RWHP and 1000RWHP respectively with larger injectors. It also works with Ford Racing #M9407 GT05 Dual Pump Kit for ‘05 up Mustang 4.6 GT (dual FPDM). Supports up to 1000 EHP depending on injector size - MORE
than a “triple” Walbro 255 hat assembly.
‘03-’04 COBRA*
‘03-’04 Cobra stock dual pump system is good for 750RWHP with only the 17.5V BOOST-A-PUMP® and 925 with the 20V with the
stock single FPDM. For over 750RWHP, use the “Dual” BOOST-A-PUMP® or use 2 of the Ford GT or Shelby pumps. Note: The ‘03’04 Cobra uses a smaller 5/16” fuel line vs. the 3/8” for the ‘05 up Mustang/Shelby.
‘99-’04 LIGHTNING (RETURN SYSTEM)*
The stock Lightning 127L pumps are good to 600HP with the “Single” BOOST-A-PUMP®.Replacing the 127L pumps with Walbro
GSS342 255L (actually 192L) will support +800HP with the “Single” BOOST-A-PUMP®. Note: We don’t recommend switching return
and returnless style pumps. Use the basic pump design the system was designed for.
‘05-’10 MUSTANG
Ford Racing #M-9407 GT05 Dual Pump Kit with Dual BOOST-A-PUMP® up to 1000HP with larger 100 lb injectors. Same fuel feed
line as Shelby and same HP potential.
DODGE, CHRYSLER 5.7 / 6.1 / 6.4
Supports 650-765RWHP with single pump, lines and rails and Kenne Bell 21V BOOST-A-PUMP®.
CAMARO 6.2 / 7.0
Supports 688-800RWHP with single pump, lines & rails and Kenne Bell 21V BOOST-A-PUMP®.
2011 UP MUSTANG 5.0 / BOSS 302
Tested by Muscle Mustangs Magazine at 854 RWHP with only a VAP, stock pump, lines, rails and Injector Dynamics 100lb injectors.
100-160lb injectors make more. Note: BIG problem upgrading to a larger pump in the stock pump hat can’t be disassembled.
BOOST-A-PUMP® increases stock pump 217L @ 12V to 549L @ 20V.
*Warning! DO NOT operate pump(s) continuously with 20V Competition BOOST-A-PUMP’s. Use pressure switch provided and activate pump(s)
ONLY when in boost. 17.5 recommended for most applications (street and competition). For max 1/4 mile, 20V is hard to beat. 20V not
recommended for road racing or long runs with pump on 20V.
2013 UP SHELBY GT500
Don’t get sucked into spending your hard earned money on new hats, pumps, lines, etc. The BOOST-A-PUMP® was tested at
+970RWHP with stock fuel system and injectors and 1100RWHP with larger injectors.
There are other OEM pumps, but these pumps cover the entire range of flow. Some pumps (Walbro/Ti) were used on multiple EOM
vehicles. Wiring size is the limitation.
*
*
*
*
*
*
*
See Kenne Bell Fuel & HP Estimator for HP and injector size.
*The Kenne Bell BOOST-A-PUMP® works with all the above listed OEM pumps and wiring. No expensive billet hats, re-wiring
or plumbing is necessary. Pumps shown with N/A are “Not Applicable.”
WARNING (Amperage)
The Walbro and Aeromotive pumps used in either single or dual applications obviously produce more flow than stock pumps BUT AMPERAGE IS MUCH HIGHER. Example: Up to 73% 14.2-17.2 vs 9.9 amps (Walbro Gss340). Therefore, the stock
wiring system is incapable of handling the increased loads and must be upgraded or replaced. This higher amperage also
negates using the BOOST-A-PUMP™ and it’s 17.5-20V advantage. The BOOST-A-PUMP™ is not designed to operate these
high amp pumps. Check out the flow numbers and cost of the 2 approaches. See Kenne Bell “Fuel & Horsepower Estimator” to
determine HP.
WARNING (Pump Type)
NEVER, NEVER switch between Gerotor (constant flow) and Turbine (pulse) type. The BOOST-A-PUMP® is designed to be
equally efficient with both, but overall flow, efficiency and operation is severely affected WITH or WITHOUT the BOOST-APUMP®. Just don’t mix them.
corelfiles\tech\boost-a-pump\fueltech.cdr rev 9/30/15