FAQ's

Is it worth changing from a 5.0 to a GT40 lower manifold? The HP gain is minimal - approx. 7HP with a GT40 lower and our supercharger. Keep in mind that our kits eliminate the upper manifold. However, the GT40 runners are more balanced and solve the 5.0's lean #8 cylinder.

Cylinders	1	2	3	4	5	6	7	8
cfm 5.0	130	147	147	148	126	147	141	159
cfm GT40	180	203	201	200	187	199	192	207

We keep saying it but air flow is everything. If #8 flows 10% more air, it leans the mixture in that cylinder 10% or about (1) air fuel ratio. So it is the one that will detonate first if there's a shortage of fuel or octane or excess boost and timing. If your goal is to run as much boost as possible, be a little safer and develop another 7HP - then go with the GT40 lower. Keep in mind that you can make 10HP with the 65mm throttle body and 20-40HP with the Kenne Bell 90mm mass air meter package.
Where do I get the most HP, inlet or exhaust? No doubt about it, the inlet on a positive displacement supercharger.

Does a 65 or 70mm throttle body improve performance? Not worth the expense on a stock engine but they are 8-12HP with one of our kits. Again, the actual engine air flow (1.5 cfm per HP) should be the ONLY factor to consider when choosing a throttle body.

When do I need the additional flow of the Kenne Bell FLOWZILLA manifold? Our stock inlet manifold is adequate up to 300 rear wheel HP. For gains above 300HP, see tests below.

Rear Wheel HP	CFM	Gain	Throttle Body
300	450	+5HP	65mm
330	495	+8HP	65mm
375	562	+25HP	75mm
425	637	+43HP	75mm
475	712	+50HP	75mm

How does supercharging work and why has it become so popular? Superchargers can increase engine output at the rate of 6-7% per psi of boost. Supercharging is "guaranteed" performance. Today, with the OEM's leaving very little, if any, performance in their vehicles, there's no guarantee that the addition of an exhaust system, headers or cool air kit will help.

Are any other changes to my engine or drivetrain necessary? No. Kenne Bell kits are complete. Everything for an easy, foolproof installation is included. And the instructions are the best in the industry.

Can the Kenne Bell supercharger damage my engine or shorten the life? The new car manufacturers don't seem to think so. Neither do we. The Mazda Millennia, new Mercedes and Ford GT offered a Twin Screw supercharger that is very similar to the Kenne Bell. Then there's the Ford Super Coupe, Jaguar, Buick V6, Lightning, Nissan, Cobra, 2004 Cobra, Shelby GT 500 etc. - all factory equipped with superchargers. All have standard factory warranties.

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