
• Huge potential. Choose your HP 658-801 & Boost 10-23 psi. Outpowers a 3.3.
• Exclusive: Mammoth 168mm Manifold / Throttle Body. +68HP vs. wimpy stock 60mm.
• New "BIG BORE™" Billet 2.8H (+56HP over 1.4 PR Twin Screw). Tested & proven design.
• 2.8 Fits under stock Shelby hood.
• 3.6 requires engine lowering or hood.
Kenne Bell factory tuned with OEM grade equipment. No expensive custom tuning by others is required or recommended unless adding headers etc. that require re-tuning. Includes Dual "POWER" & "SHOOT OUT" tune in SCT X Cal



• Boost is “peak” data logger reading on our Dynojet Dyno measured after the intercooler. Actual boost will vary depending on 1. pulley size 2. inlet components and 3. engine rpm. See “BOOST RATINGS” below.
• Headers, exhaust, cams and heads can also lower boost.
• Bone stock Eaton 3” pulley 8.5 psi = 441HP.
• HP numbers are SAE on Kenne Bell Dynojet.
• Anyone can make more HP with our kits by revving the engine beyond 6200.
• Keep engine rpm at 6200. Ford DOES NOT recommend increasing the rpm limiter.
• We recommend Dynos that use the AFM1000, ETAS or Horiba AF ratio meters/sensors (oxygen sensors) with a bung - no tailpipe sensors. See “Dyno Testing Variables.”
CAUTION: These kits were designed to produce maximum power and performance. BE CAREFUL. Traction is a problem. The driveshaft needs to be upgraded and a safety plate installed at higher power levels.
![]()

The perfect technological match - Kenne Bell and the fabulous Ford 5.4 4V. Never have there been kits with so much HP potential and flexibility in choice and never has there been a Ford engine like the 5.4 4V. The Shelby 5.4 engineered cars are strong and durable because they were designed specifically for a supercharger. Best of all, the 5.4 4V has tremendous HP potential, given the Kenne Bell supercharger and inlet component upgrades. And it all fits under the stock Shelby hood.
We Replace the stock restrictive 60mm throttle body and inlet tube with the Kenne Bell Dual 75mm Throttle Body and Big Oval Inlet Tube (+26-74HP depending on pulley size). +26HP (692 vs. 666) with the stock 3” pulley size. That’s almost 700HP at 15.5 psi. Then there are the smaller pulleys. 2-7/8” (728HP), 2-3/4” (764HP) and 2-1/2” (801HP) - all the HP the stock engine and drivetrain can handle. This is truly a “max” performance kit.
Also larger 3-1/4” and 3-1/2” pulleys that lower kit power to as little as 627HP for those who want less HP. Overall HP range is 627-801 (+100-257HP) with NO other engine or fuel system mods except for the Kenne Bell DUAL BOOST-A-PUMP™ and a set of 1 heat range cooler plugs. See “Shelby Dyno Test Summary” for HP and TQ matrix and select the HP that best suits your needs. Think seriously about spending your money on expensive headers (10-15HP), cams (25HP) etc. and labor when the Kenne Bell Kits will give you ALL the extra HP you’ll ever need with a simple low cost pulley/boost upgrade (20-44HP per 1/4” pulley size).
These aren’t kits we just threw together, letting our customers and tuners eventually “figure it all out.” The timing was set at 23°, AF at 11.5 and we made hundreds of accurate SAE back to back Dynojet tests with the various pulleys on the Stage 1-3 kits. Once completed, we organized the test data into a format that helps our customers make intelligent decisions based on fact instead of opinion, heresay or agendas. Most were at 1.03 SAE so for “actual” or “uncorrected” Dynojet numbers, multiply the Kenne Bell HP numbers by .97 if you believe the Society of Automotive Engineers are all wet.
The Kenne Bell Big Oval Meter, Filter and Tube and the Dual 75mm Throttle Body are maximum performance Kenne Bell engineered, tested and calibrated products. Based on the flow bench and dyno data, one would be hard pressed to improve on any of the Kenne Bell inlet pieces.
WHY MORE HP WITH THE SAME BOOST/PULLEY?
We’ve published a lot of information on the Shelby, but the following HP examples will explain why we talk so much about inlet systems. If we’ve learned one thing in our 20 years of Ford Twin Screw kit design, it is KEEP INLET SYSTEM LOSSES TO A MINIMUM. Supercharger size, efficiency and even boost are secondary if the inlet system is undersized and cannot supply sufficient air flow to the supercharger. It acts as a restrictor plate. Like a 2bbl carburetor on a 500” engine. The supercharger must spin faster to make up for the inlet boost loss. It then uses MORE engine HP to make the same boost. Oops! Remember that inlet restrictions LOWER the atmospheric pressure into the supercharger - and the actual boost the engine therefore sees. It’s a lose-lose situation. Example: Here is why the Kenne Bell 75mm manifold, throttle body etc. are so important to the HP a supercharger develops.
DO I NEED UPGRADES?
Our kits were designed to leave no one hanging and wishing they could step up the power with some quick simple supercharger bolt ons. Note that any one poor flowing component can limit the flow of the other inlet parts anywhere in the chain. The mammoth sized Kenne Bell Dual 75mm “Mammothfold” flows more air than even the big 75mm throttle body. It blows away the competition. The engine makes more power because the supercharger uses less engine HP with a cooler air discharge temp.




![]()

All Kenne Bell supercharger kits are designed, assembled, calibrated and tuned in house and then sold and serviced (tech support, repairs, warranty etc). factory direct. Selling factory direct to our customers and select Authorized Installers/Dealers eliminates the middleman (web retailer) profit enabling us to offer a better product for less money. And Kenne Bell kits are complete with the industry’s best Installation Instructions. Our kits are not “finished up” or cobbled together by some web vendor and custom tuned by yet another. There are no hidden extras, add ons, custom tuning, agendas etc. And they are 50 State Legal.
Compare the advantage of buying factory direct, the features, what’s included, and all that “room to grow” and you’ll see that a Kenne Bell kit offers far more but can actually cost less than the competition. And it makes more HP. See Back to Back H Comparisons 807 (2.8H) vs. 792 (3.3/3.4) at same 24 psi boost.
STANDARD EQUIPMENT INCLUDED IN KENNE BELL 2.8H SHELBY GT 500 STAGE 3 KIT
$______ “POWER” & “SHOOT OUT” (Street & Competition) Dual Calibration. Turn the key and it's ready to go.
Note: Custom Tuning can cost $1000-$1500 in labor alone - once you tow the car to a dyno.
$______ Kenne Bell Factory Direct Tech Support. Best Mustang tech people in industry.
$______ MAFIA mass air flow meter extender.
$______ 800+HP fuel system (DUAL BOOST-A-PUMP™). More reliable / less heat than larger pumps.
$______ 627-801HP with ONLY pulley changes. No "special" tunes required for every pulley.
$______ Pump voltage / fuel delivery / pressure regulated 100% accuracy with Dual BOOST-A-PUMP™.
$______ Mammoth dual 75mm inlet manifold (1835 cfm).
$______ Dual 75mm throttle body (1880 cfm) + 74HP.
$______ 130mm meter / 130mm filter (1830 cfm) + 20HP.
$______ Huge Ford GT Supercar inlet tube.
$______ Billet (not cast) high rpm - high boost Twin Screw. Less heat soak from engine heat.
$______ Room to grow. TVS 2.3 Roots Style very limited on HP potential vs. KB 2.8H Twin Screw.
$______ Includes all gaskets.
$______ Includes instructions (some kits don't furnish instructions).
$______ . . . And it all fits under the stock hood. Saves cost of new hood, fitting and painting.
$______ . . . No engine and trans lowering body raising kits to misalign driveshaft.
$______ No reduced header and oil pan ground clearance from lowered engine.
![]()
Unquestionably, the new 605HP Ford (Eaton TVS 2.3L) kit is superior to the 500HP ‘07 Shelby (Eaton 2.1L) kit or the 550HP ‘08 KR (Eaton 2.1L) kit - but the Kenne Bell also keeps improving in efficiency. The Eaton TVS 2.3L is available on the lower HP 605HP version of the Shelby “Super Snake.” The Kenne Bell high HP 2.8H Kit, which is also available on the “Super Snake” is rated at 725HP WITH ROOM TO GROW! The TVS is used up at 14.5 psi. Statements about how “efficient” a new supercharger is can be misleading. The real test of a supercharger kits output and potential is to simply compare both with 1. the same size pulleys and 2. with the smallest pulley on a dyno and then datalog the numbers. Below are 3” and 2.5” comparisons.


SUPERCHARGER – INLET MANIFOLD DESIGN & HP POTENTIAL (ONE PIECE vs TWO PIECE) Any superchargers potential is ALWAYS limited by the inlet system. If the inlet manifold is too small, it becomes the restriction to higher HP. Imagine an engine block and inlet manifold cast as a “one piece” casting that cannot be separated. An intergral supercharger – inlet manifold casting is used by the OEM because it costs less to manufacture. Unfortunately, the manifold cannot be replaced or upgraded for a larger throttle body, etc. and “porting” results in minimal, if any, gains. So if it is too small for your HP requirments, you are stuck as both the manifold and supercharger are too small. Kenne Bell billet superchargers and cast inlet manifolds are independent of each other and larger than the competition. They may cost more, but larger manifolds coupled to larger and/or more efficient superchargers means more HP for your dollar up front – and more room to grow.
THROTTLE BODY SIZE
The Kenne Bell Mammoth Manifolds (Ford, Dodge & Camaro) incorporate a huge 79mm x 168mm opening to accommodate the huge Dual 75mm (1880 CFM) or Mammoth Big Oval (2150 – 2350 CFM) Throttle bodies. A big HP throttle body doesn’t work very well on an “undersized” supercharger inlet manifold.

Home | Superchargers | Accessories | FAQ's | Tech Info | Price List | Tech Articles | Reman SC | Company | Contact Us | Policies
Copyright © 2011 Kenne Bell, Inc. All Rights Reserved

The secret to the Kenne Bell kit’s superior performance is the exclusive mammoth sized 168mm x 79mm Inlet Manifold and matching Dual 75mm or 168mm Throttle Body. No other kit has it. Supercharger size and efficiency are meaningless if even ONE inlet system component is restrictive or undersized. That’s the best way to kill HP and efficiency (boost, temp and parasitic loss) with ANY positive displacement supercharger i.e. makes it work harder. So, at what HP level does the little stock 60mm throttle body begin starving a supercharged Shelby and killing off HP? One look at our back to back - one change at a time Kenne Bell Shelby dyno tests tells us the answer in approx. 435HP, the average for a STOCK Shelby. So don’t buy a larger throttle body for any Shelby supercharger that only makes 435RWHP @ 6200. At a mere 435HP, the 60mm begins to show it’s limitations. Then at 6300 rpm, the 75mm pulls away by 26HP (658 vs. 632)! And in the 700HP range, the highly restrictive stock 60mm is choking the supercharger off even more by up to 74HP. Note the higher the HP/air flow, the greater the power gains from larger inlet components. For more information on the 60 vs. 75 throttle body/manifold and meter/filter, see “Shelby Dyno Test Summary.” Again, ANY positive displacement supercharger responds especially well to a SERIES of larger inlet components (throttle body, hose, meter, filter). If ONE is restrictive, it chokes off the air flow to ALL of the others, including the supercharger. Anyone who doubts that Kenne Bell 75mm components are a must need only ask Ford engineers why they used a 70mm on the Ford GT Supercar - an engine that makes up to 100HP LESS than a Kenne Bell Shelby.
Note: For ultra high HP competition applications use the KB 168mm 2150 - 2350 Throttle Body.
Designed for the Shelby GT 500, ’05 up Mustang GT, ’03 Cobra & Hemi. Mammoth Kits. Rated up to 800RWHP/940EHP. Stock 60MM and other replacement 62-66MM throttle bodies are too small and lack sufficient air flow for higher HP applications.
Note: Must be used with Mammoth 4.5”/113MM inlet. Note: Smaller filter, meter, inlet pipe & manifold will restrict air flow and limit HP potential of the throttle body. Recommended for Mammoth manifolds only.
![]()
• Rated 800RWHP/940EHP
• + 48-84RWHP vs Stock 60MM
• + 24RWHP vs 66MM
• Matches Mammoth Manifold Opening (79MM x 168MM)
• Special Tuning Required
• 800RWHP/940EHP
• Mirror Polished Billet Aluminum
• Available DBW or Manual Throttle
![]()

![]()

Read what Technical Editor, Tom Wilson, has to say about dyno testing and driving the new Kenne Bell 2.8H 800HP Shelby Kit.
Cover Car: March '07 issue 5.0 Mustang Magazine