SUPERCHARGER DATA
#1
06-29-2004, 02:00 AM
SUPERCHARGER DATA
Kenne-Bell
Does the supercharger decrease my fuel mileage?
Not under normal driving conditions. However, if you use the boost it will, of course, use more fuel. You can't make power without fuel.
What kind of performance increase can I expect from my Kenne Bell Supercharger Kit?
Approximately 30-50%. Check out the individual catalog listings.
Why is a supercharger better than other performance modifications?
A Kenne Bell Supercharger is by far the best performance value of all. You can spend more money on exhaust, headers, cool air, chip, cam etc. and not get anywhere near the performance you would from the supercharger kit. Besides, the OEM's aren't leaving much HP - if any - in the above mentioned products. That is precisely why they are now resorting to supercharging for big performance gains. See our "Bolt on parts vs. supercharger" comparison that Super Ford Magazine did on a Mustang. Pay particular attention to the low and mid range gains with the supercharger.
What parameters determine how much boost my engine can run on 92 octane? Good question. One of the top 3 most commonly asked.
COMPRESSION RATIO - Lowering the compression ratio allows the engine to run more boost with the same octane. For example, 8.0:1 vs 9.5:1 can tolerate another 3 psi. 3 psi gives 38HP. The 1.5 lower CR loses 3% (2% per point) or around 9HP in a 300HP engine. That nets 29HP (38-9=29). Now you know why OEM's use low compression ratios on supercharged engines.
AIR CHARGE TEMP - The supercharger itself determines how much boost the engine will accept. Some superchargers require an intercooler. Others, such as the Kenne Bell, don't need intercoolers because the discharge air temp is cooler. 1 psi boost increases supercharger air discharge temperature 10°-20°, depending on supercharger type. A 6 psi "rated" kit usually requires 8 psi "total" boost (+2 psi to overcome inlet and outlet losses). Consider two 8 psi superchargers: 8x10=80°, 8x20°=160°. The 160° supercharger should use an intercooler. An air to water intercooler will lower that 160° to around 80° (160°-80°=80°) or the 80° temperature of a more efficient supercharger without an intercooler.
BOOST - Both higher compression ratios and boost increase cylinder pressure and demand higher octane fuels to eliminate detonation. Fuel octane determines the amount of boost an engine will accept. Kenne Bell runs 6-7 psi on all our Ford, GM, Chrysler and most other kits with our Twin Screw superchargers. One octane will support one psi of boost. Example: If fuel octane is 94 or you add a can of NOS Octane Booster you can typically run 8 psi.
IGNITION TIMING - Retarding ignition timing will allow the engine to run more boost but not without a penalty. 4° retard=16HP.
AIR FUEL RATIO - You can't make horsepower without fuel. Richer air fuel ratios reduce power but permit higher boost levels on a given fuel octane. Leaner ratios make more power but need lower boost so a lean mixture with high octane makes the most HP. We thoroughly understand all the parameters of supercharging. Supercharger kit tuning demands ignition timing, air fuel ratio, fuel octane, boost, compression ratio, discharge temperature and supercharger parasitic losses all be carefully considered in the design.
What causes detonation? 1. Lean fuel mixture, 2. low octane fuel, 3. excess boost, 4. lack of fuel, 5. advanced ignition timing, 6. vacuum leak, 7. "hot" spark plugs, 8. overheated engine, 9. excessive inlet temperature (underhood filter).
Why does Kenne Bell use a 6 rib belt to drive the supercharger and others use an 8 rib belt?
Because our Twin Screw supercharger has less parasitic loss than others and therefore requires less HP to drive - which means the engine develops more HP with a Kenne Bell.Does Kenne Bell supply "knock protection" with their kits? We call it "detection/protection." There must first be "detection" and then automatic "protection" from detonation. Protection from potentially engine damaging detonation (knock, ping) is our #1 priority at Kenne Bell. We've led the pack for years in this department. The turbocharged Buick V6 utilized knock protection way back in 1978! GM and Ford have used knock protection since the 90's. We modify and/or expand the OEM protection in our supercharged calibrations. Most Chrysler engines except for the late 3.7 Jeep V6 and PT Cruiser do not use knock detection. Kenne Bell engineered our own knock system for the 5.3, 5.9 and 4.7 Chrysler products.
Does Kenne Bell sell a mass air meter? Yes, we offer only one - a 90mm for Mustangs and the 4.6/5.4 trucks and SUV's. They are sold only with a chip and will increase horsepower and torque on ANY Ford V8 or your money back. How much of an increase depends entirely on the HP (airflow) of the engine - or how much of a restriction the meter is creating. Expect 5-50HP. Always use at least 80mm.
Can I change mass air meters? By far our number one complaint. A larger mass air meter theoretically makes more HP if the one you have is too small for the engines air flow. If it isn't, the HP increase is "0." Factory engineers spend considerable time calibrating their engines to a specific computer. Then someone "just sticks on a new meter?" No, No, that's not the way it's done. The computer must be re-calibrated and never, never, ever install a meter and larger injectors without re-calibrating the computer or installing the proper re-calibrated chip. METERS CANNOT BE "RE-CALIBRATED" FOR LARGER INJECTORS. Changing the voltage signal to the meter via "re-calibration" by the supplier or with "adjustable *****" only compensates for the larger injectors at wide open throttle. The computer load tables and transfer function is also adversely affected. The timing is advanced. We've seen up to 52° vs. stock 30° and lean, lean air fuel ratios - all at the wrong time. Anyone who disagrees might just check with Ford FRP or a Ford engineer.
Headers? 4 tube or Tri-Y? 4 tube headers work very well on the 5.2 and 5.9 Dodges (20HP) and 12HP on the 4.7's and Chevies. 12HP is only 1 car length in the 1/4 mile. 12HP is hard to feel. We've never seen any worthwhile gains on the 4.6, 5.4 Ford/Lincoln, PT Cruiser or Escape from any header. I never saw a set of Tri-Y's worth installing. We don't recommend them nor have we ever witnessed that "improved low and mid range" they yak about. Has anyone EVER seen a successful drag racer running Tri-Y's? Of course not.
How can I tell if my filter assembly, meter, throttle body inlet hoses or manifolds are restrictive and losing HP? Use the time-proven Kenne Bell approach. Flow the individual pieces on a flow bench. If you don't have access to a bench, install a tap behind each component in the inlet track, make a dyno pull or a WOT run on the street in low or second gear and read the vacuum gauge. If it's "0" there are no losses and, therefore, upgrading components will not help. However, if there is a 4" Hg reading - that's 2 psi of lost atmospheric boost and 20HP (1 psi=10HP). Works on carbureted engines also. Now you know how to analyze inlet systems. You'd be amazed at how many don't.
How do I determine if there is any HP potential in the exhaust system? Again, if you don't have a flow bench and the historical data for analysis, try another Kenne Bell approach. Cut off the entire exhaust in back of the catalytic converter and compare the runs on the dyno. You should also measure back pressure. If there is a gain, then you have to design - or find an exhaust system that can flow as much air as no exhaust system. As we've mentioned previously, there's not much HP left in the new vehicles, particularly the Fords, Chevies, Dodge 4.7, Jeep 3.7 and PT Cruiser. That's exactly why supercharging has become so popular - the HP is guaranteed.
Will an ignition system make more HP? Absolutely not. How can it if the engine is not missing to begin with. "Hotter" spark does not make more HP or improve fuel mileage. We've all seen those ads claiming "Tremendous gains in HP and torque" - "23HP!" etc. . . No way. Let's test it on our dyno anytime at no cost with a magazine in attendance. If you're running high boost and the engine is misfiring, first reduce the plug gap to .035", then try Denso Iridium plugs. If that doesn't solve the problem, then install a hotter ignition system.
What's the best 5.0 Mustang performance book? By far the best book on the 5.0 Mustang is the SA Design "5.0L Ford Dyno Tests" by Richard Holdener. He's documented over 2000 dyno pulls. All good accurate data. Available thru Car Tech, 11605 Kost Dam Rd., North Branch, MN. 55056. Phone (800) 551-4754.
What spark plug should I run with a supercharger? One heat range cooler than stock. Denso Iridium is the best plug we've ever tested. Avoid Platinum plugs. Always set gaps at .035". Denso irridiums are factory gapped at .044".
What is the maintenance on a Kenne Bell Twin Screw? Virtually none. It's internally lubricated and uses lifetime sealed bearings. We have NEVER seen bearing failure in an Autorotor. Just change the synthetic oil (6 oz.) in the reservoir every 12,000 miles.
Do I need an adjustable fuel pressure regulator? Unless you're playing with an '86-'93 Mustang, don't bother.
What is the most ridiculous aftermarket product? Hands down, it's the "little intake fans" and the "throttle body spacers" with the bore grooves. Right there on the list has to be those "underhood exposed filters" that suck in 200° underhood air instead of ambient (70°-100° air from the fenderwell). 10° air temp rise is -1% HP. That's how dynos are calibrated for temperature changes. Does anyone really believe that all those OEM manufacturers designed expensive plastic inlet systems - for the last 20 years - that pull cool air from the fenderwell, hood or grill because they didn't have anything else to spend their money on? Then there's those "factory calibrated" mass air meters that do not use a chip or re-calibrated processor with oversize injectors. They unwittingly reduce the voltage signal to the mass air meter to compensate for the larger injectors at WOT but they neglect all the driveability issues. The result is over advancing timing, lean mixtures, detonation, surging, bucking etc.
Why is knock protection so important? Knock (detonation) can destroy your engine if it is not negated. Suppose your wife or a friend unknowingly fills your tank with 87, or you get a "bad batch" of gas, the engine overheats, someone installs a pulley that raises supercharger boost, the wrong spark plug heat range is installed (too hot) or a vacuum leak develops and the engine leans out. That's when an engine needs knock protection. No one in this industry has more experience than Kenne Bell with knock protection.
Does the supercharger decrease my fuel mileage?
Not under normal driving conditions. However, if you use the boost it will, of course, use more fuel. You can't make power without fuel.
What kind of performance increase can I expect from my Kenne Bell Supercharger Kit?
Approximately 30-50%. Check out the individual catalog listings.
Why is a supercharger better than other performance modifications?
A Kenne Bell Supercharger is by far the best performance value of all. You can spend more money on exhaust, headers, cool air, chip, cam etc. and not get anywhere near the performance you would from the supercharger kit. Besides, the OEM's aren't leaving much HP - if any - in the above mentioned products. That is precisely why they are now resorting to supercharging for big performance gains. See our "Bolt on parts vs. supercharger" comparison that Super Ford Magazine did on a Mustang. Pay particular attention to the low and mid range gains with the supercharger.
What parameters determine how much boost my engine can run on 92 octane? Good question. One of the top 3 most commonly asked.
COMPRESSION RATIO - Lowering the compression ratio allows the engine to run more boost with the same octane. For example, 8.0:1 vs 9.5:1 can tolerate another 3 psi. 3 psi gives 38HP. The 1.5 lower CR loses 3% (2% per point) or around 9HP in a 300HP engine. That nets 29HP (38-9=29). Now you know why OEM's use low compression ratios on supercharged engines.
AIR CHARGE TEMP - The supercharger itself determines how much boost the engine will accept. Some superchargers require an intercooler. Others, such as the Kenne Bell, don't need intercoolers because the discharge air temp is cooler. 1 psi boost increases supercharger air discharge temperature 10°-20°, depending on supercharger type. A 6 psi "rated" kit usually requires 8 psi "total" boost (+2 psi to overcome inlet and outlet losses). Consider two 8 psi superchargers: 8x10=80°, 8x20°=160°. The 160° supercharger should use an intercooler. An air to water intercooler will lower that 160° to around 80° (160°-80°=80°) or the 80° temperature of a more efficient supercharger without an intercooler.
BOOST - Both higher compression ratios and boost increase cylinder pressure and demand higher octane fuels to eliminate detonation. Fuel octane determines the amount of boost an engine will accept. Kenne Bell runs 6-7 psi on all our Ford, GM, Chrysler and most other kits with our Twin Screw superchargers. One octane will support one psi of boost. Example: If fuel octane is 94 or you add a can of NOS Octane Booster you can typically run 8 psi.
IGNITION TIMING - Retarding ignition timing will allow the engine to run more boost but not without a penalty. 4° retard=16HP.
AIR FUEL RATIO - You can't make horsepower without fuel. Richer air fuel ratios reduce power but permit higher boost levels on a given fuel octane. Leaner ratios make more power but need lower boost so a lean mixture with high octane makes the most HP. We thoroughly understand all the parameters of supercharging. Supercharger kit tuning demands ignition timing, air fuel ratio, fuel octane, boost, compression ratio, discharge temperature and supercharger parasitic losses all be carefully considered in the design.
What causes detonation? 1. Lean fuel mixture, 2. low octane fuel, 3. excess boost, 4. lack of fuel, 5. advanced ignition timing, 6. vacuum leak, 7. "hot" spark plugs, 8. overheated engine, 9. excessive inlet temperature (underhood filter).
Why does Kenne Bell use a 6 rib belt to drive the supercharger and others use an 8 rib belt?
Because our Twin Screw supercharger has less parasitic loss than others and therefore requires less HP to drive - which means the engine develops more HP with a Kenne Bell.Does Kenne Bell supply "knock protection" with their kits? We call it "detection/protection." There must first be "detection" and then automatic "protection" from detonation. Protection from potentially engine damaging detonation (knock, ping) is our #1 priority at Kenne Bell. We've led the pack for years in this department. The turbocharged Buick V6 utilized knock protection way back in 1978! GM and Ford have used knock protection since the 90's. We modify and/or expand the OEM protection in our supercharged calibrations. Most Chrysler engines except for the late 3.7 Jeep V6 and PT Cruiser do not use knock detection. Kenne Bell engineered our own knock system for the 5.3, 5.9 and 4.7 Chrysler products.
Does Kenne Bell sell a mass air meter? Yes, we offer only one - a 90mm for Mustangs and the 4.6/5.4 trucks and SUV's. They are sold only with a chip and will increase horsepower and torque on ANY Ford V8 or your money back. How much of an increase depends entirely on the HP (airflow) of the engine - or how much of a restriction the meter is creating. Expect 5-50HP. Always use at least 80mm.
Can I change mass air meters? By far our number one complaint. A larger mass air meter theoretically makes more HP if the one you have is too small for the engines air flow. If it isn't, the HP increase is "0." Factory engineers spend considerable time calibrating their engines to a specific computer. Then someone "just sticks on a new meter?" No, No, that's not the way it's done. The computer must be re-calibrated and never, never, ever install a meter and larger injectors without re-calibrating the computer or installing the proper re-calibrated chip. METERS CANNOT BE "RE-CALIBRATED" FOR LARGER INJECTORS. Changing the voltage signal to the meter via "re-calibration" by the supplier or with "adjustable *****" only compensates for the larger injectors at wide open throttle. The computer load tables and transfer function is also adversely affected. The timing is advanced. We've seen up to 52° vs. stock 30° and lean, lean air fuel ratios - all at the wrong time. Anyone who disagrees might just check with Ford FRP or a Ford engineer.
Headers? 4 tube or Tri-Y? 4 tube headers work very well on the 5.2 and 5.9 Dodges (20HP) and 12HP on the 4.7's and Chevies. 12HP is only 1 car length in the 1/4 mile. 12HP is hard to feel. We've never seen any worthwhile gains on the 4.6, 5.4 Ford/Lincoln, PT Cruiser or Escape from any header. I never saw a set of Tri-Y's worth installing. We don't recommend them nor have we ever witnessed that "improved low and mid range" they yak about. Has anyone EVER seen a successful drag racer running Tri-Y's? Of course not.
How can I tell if my filter assembly, meter, throttle body inlet hoses or manifolds are restrictive and losing HP? Use the time-proven Kenne Bell approach. Flow the individual pieces on a flow bench. If you don't have access to a bench, install a tap behind each component in the inlet track, make a dyno pull or a WOT run on the street in low or second gear and read the vacuum gauge. If it's "0" there are no losses and, therefore, upgrading components will not help. However, if there is a 4" Hg reading - that's 2 psi of lost atmospheric boost and 20HP (1 psi=10HP). Works on carbureted engines also. Now you know how to analyze inlet systems. You'd be amazed at how many don't.
How do I determine if there is any HP potential in the exhaust system? Again, if you don't have a flow bench and the historical data for analysis, try another Kenne Bell approach. Cut off the entire exhaust in back of the catalytic converter and compare the runs on the dyno. You should also measure back pressure. If there is a gain, then you have to design - or find an exhaust system that can flow as much air as no exhaust system. As we've mentioned previously, there's not much HP left in the new vehicles, particularly the Fords, Chevies, Dodge 4.7, Jeep 3.7 and PT Cruiser. That's exactly why supercharging has become so popular - the HP is guaranteed.
Will an ignition system make more HP? Absolutely not. How can it if the engine is not missing to begin with. "Hotter" spark does not make more HP or improve fuel mileage. We've all seen those ads claiming "Tremendous gains in HP and torque" - "23HP!" etc. . . No way. Let's test it on our dyno anytime at no cost with a magazine in attendance. If you're running high boost and the engine is misfiring, first reduce the plug gap to .035", then try Denso Iridium plugs. If that doesn't solve the problem, then install a hotter ignition system.
What's the best 5.0 Mustang performance book? By far the best book on the 5.0 Mustang is the SA Design "5.0L Ford Dyno Tests" by Richard Holdener. He's documented over 2000 dyno pulls. All good accurate data. Available thru Car Tech, 11605 Kost Dam Rd., North Branch, MN. 55056. Phone (800) 551-4754.
What spark plug should I run with a supercharger? One heat range cooler than stock. Denso Iridium is the best plug we've ever tested. Avoid Platinum plugs. Always set gaps at .035". Denso irridiums are factory gapped at .044".
What is the maintenance on a Kenne Bell Twin Screw? Virtually none. It's internally lubricated and uses lifetime sealed bearings. We have NEVER seen bearing failure in an Autorotor. Just change the synthetic oil (6 oz.) in the reservoir every 12,000 miles.
Do I need an adjustable fuel pressure regulator? Unless you're playing with an '86-'93 Mustang, don't bother.
What is the most ridiculous aftermarket product? Hands down, it's the "little intake fans" and the "throttle body spacers" with the bore grooves. Right there on the list has to be those "underhood exposed filters" that suck in 200° underhood air instead of ambient (70°-100° air from the fenderwell). 10° air temp rise is -1% HP. That's how dynos are calibrated for temperature changes. Does anyone really believe that all those OEM manufacturers designed expensive plastic inlet systems - for the last 20 years - that pull cool air from the fenderwell, hood or grill because they didn't have anything else to spend their money on? Then there's those "factory calibrated" mass air meters that do not use a chip or re-calibrated processor with oversize injectors. They unwittingly reduce the voltage signal to the mass air meter to compensate for the larger injectors at WOT but they neglect all the driveability issues. The result is over advancing timing, lean mixtures, detonation, surging, bucking etc.
Why is knock protection so important? Knock (detonation) can destroy your engine if it is not negated. Suppose your wife or a friend unknowingly fills your tank with 87, or you get a "bad batch" of gas, the engine overheats, someone installs a pulley that raises supercharger boost, the wrong spark plug heat range is installed (too hot) or a vacuum leak develops and the engine leans out. That's when an engine needs knock protection. No one in this industry has more experience than Kenne Bell with knock protection.
