





*Fuel octane, fuel system, boost, ignition timing, engine durability, other products, engine size etc. will determine actual HP potential.


INTRODUCTION
At Kenne Bell, we believe that decisions are best made when all the facts are known - and the more you look, the better we look. We try to cover any foreseeable question, and therefore, go to great lengths to supply our customers with all the information (tests, tuning, comparisons, related products, tech info, etc.) necessary to understand our products and related components. The kit concept, it’s features and components are all thoroughly explained, followed by our LS Tech Tips. The Kenne Bell Twin Screw Kit may cost a little more, but if offers more - much more. The best of everything. Uncompromising Kenne Bell engineering heritage and tuning. No “upgrading,” or “porting” or “re-tuning” etc. is necessary. This is no wimpy OEM grade Eaton 90 (1.5L/415HP max) or Eaton 112 (1.84L/453HP max). These are numbers published in Eaton literature. Boost range is 5-18 psi with no boost drop off. And you won’t get sleepy or hungry waiting for the boost and HP to build up as with centrifugals or turbos. Always look at the torque at 2000, 2500, 3000, 3500, 4000 and 4500 and not just “peak” numbers - unless, of course, you plan on driving around town at 6500 100% of the time. All kits feature gobs of boost (HP & torque) at ANY rpm, not just “peak” rpm.
THE KENNE BELL TWIN SCREW SUPERCHARGER
The ultimate supercharger kit for the GM LS engine family. Simply the best of everything - bulletproof billet construction, max HP and torque at ANY rpm, 5-18 psi boost range with no “boost drop off,” big potential for future upgrades or higher boost weekend or competition racing, quiet operation, intercooled - and Kenne Bell engineered and calibrated. No other supercharger produces more boost (HP & torque) throughout the engine’s rpm band. Any knowledgeable automotive engineer knows the Twin Screw has proven to be the most overall efficient supercharger. Although the Eaton/Roots style is an excellent OEM style cast aluminum case supercharger with a great reputation for reliability, the Twin Screw will always make more HP and torque simply because it requires less engine HP to drive, has a cooler air discharge temp and a higher volumetric efficiency (air in vs. air out). That is why the Twin Screw has become the choice for both OEM and aftermarket vehicles where maximum peak HP is desired without sacrificing low and mid range boost. There is a trend. Ford selected the Twin Screw for it’s most prestigious and expensive car ever - the Ford GT. Mercedes and Cadillac use a Twin Screw in place of the Eaton on their high HP vehicles. Then there’s all those factory supercharged Cobras and Lightnings that upgraded - and continues to replace - their Eatons with the Kenne Bell Twin Screw superchargers. Has anyone ever heard of a Twin Screw being replaced by an Eaton/Roots style?
It’s also important to understand that the Twin Screw does not depend on engine rpm to generate more boost/air flow as do the centrifugals or turbos. Instead, the Kenne Bell “stores” it’s air supply (boost) much like a huge air tank. Boost (zero, partial or full) is always there and is regulated by your foot. The farther down the gas pedal, the more boost it makes. Nitrous also makes good power, but unlike the Kenne Bell, it’s either “all on” or “all off.”
BILLET CONSTRUCTION
Besides its hi-tech, intimidating and expensive appearance, the billet Kenne Bell supercharger is stronger - at any boost and rpm level. Any engineer, engine builder or hot rodder prefers billet. Consider this. If billet wasn’t a superior concept, then billions of consumers hard earned dollars has been wasted on upgrading from lower cost less durable cast to stronger billet components e.g. rods, cranks, gears, cams, rocker arms, pumps, shafts, etc., etc. These are not lower cost mass production OEM cast Roots type superchargers and drives “adapted” to the aftermarket. Both are, instead, limited production CNC machined 100% billet aluminum and steel. Even the bypass valve is billet. The inlet and discharge openings are precision machined for optimum and consistent air flow. Only the front cover is cast as it merely stores the supercharger oil. The drive is also 100% billet. And it uses huge bearings and shafts that are 47% larger than the competition.
CORVETTE vs. STREET ROD - OFF ROAD KITS
The same basic kit is used on both the Corvette and Street Rod - Off Road applications. The differences are listed below. The supercharger kits major components (see photo) are assembled and ready to bolt on the engine. The only options are pulley size, pulley ribs and injector size. The inlet manifold will accept stock 76mm LS1, 90mm LS2 or aftermarket FAST 90mm - and the new 93mm, when available. That’s a 30HP bolt on. Most of the Street Rod - Off Road applications use a Stand Alone System and 90mm throttle body. The Corvette inlet system and hood are not used. Below are the only differences in the kit.
PARTS NOT INCLUDED IN THE STREET ROD - OFF ROAD KIT
93mm filter
93mm One piece plastic inlet tube
93mm Clamps and hose adaptors
76mm Adaptor (allows use of stock TB)
Kenne Bell BOOST-A-PUMP™
Kenne Bell fiberglass hood
Injectors
Flash Tuner
TRUCK / SUV KITS
The 5.3, 6.0, 6.2 “TS” kits use the exact same kit as the Corvette except for the inlet system in front of the throttle body and some minor hardware changes.
SUPERCHARGER POTENTIAL
We crammed in the biggest, baddest, most efficient supercharger that would fit under our hood - one that’s just loafing around 550RWHP. Most of our customers will be more than satisfied with our standard 7 psi kit. Consider a good ZO6 is 360RWHP and the LS7 7.0L is “only” 460RWHP, but the Kenne Bell is 525RWHP with a 700+RWHP potential. Yet the driveability and factory feel is not sacrificed - except your 5.7 feels like a 9.0L at ANY rpm when the pedal is pushed down enough for the boost to kick in. An Eaton doesn’t even come close to matching this supercharger.
Yes, Kenne Bell kits are overdesigned or overkill, but our big supercharger won’t leave you hanging and your supercharger gasping for air - and boost - unable to keep up with the increasing engine HP/air flow from heads, cams etc. (see “Boost Drop Off Comparison”). If the boost drops with a Kenne Bell, you won’t have to spring for a supercharger upgrade. Instead, simply install a smaller pulley on your Kenne Bell to bring back or increase boost. And unlike the Eaton, our drive does not limit pulley size and boost. The “Big Bore” Kenne Bell reflects the absolute latest in Twin Screw rotor profile technology. It is capable of 950+ engine HP, yet works equally well at lower power levels. 600HP is easy.
All else equal at a given boost, a larger supercharger can enjoy some advantages over a smaller faster spinning supercharger:
1. A larger displacement supercharger obviously offers more HP potential.
2. It runs cooler because it spins slower.
3. Bearing speed friction and oil temperature are reduced.
4. Cooler air charge temperature.
5. Lower parasitic loss (less engine HP to spin).
6. Larger pulleys have more surface area for less belt slippage and wear.
In the case of an Eaton 112 vs. the Kenne Bell Twin Screw, the KB pulley is typically at least a full 25% larger in circumference which equates to 25% more belt contact area and less potential belt slippage. Also, the Eaton 112 suffers from “boost drop off” at higher boost levels.
FORWARD TOP MOUNT SUPERCHARGER
At Kenne Bell, we prefer the more traditional and intimidating retro - drag race - street rod look of a supercharger mounted on top of the GM V8 small block - facing forward with the drive and belt up front. We believe it just looks more impressive than a centrifugal, turbo or backward mount positive displacement. A rear drive backward facing Twin Screw configuration was considered but the complexity, reliability, cost and HP loss of the additional shafts, pulleys, belt and bearings etc. was shelved in favor of the more conventional forward mount.
93MM INLET MANIFOLD
The manifold is designed to accept either the stock 76mm or 90-93mm upgrades at no extra cost. The conversion is simple and worth 30HP. Just remove the stock throttle body plate and bolt on your 90mm. The stock 90mm LS2 DBW (drive by wire) is the most popular upgrade for Corvettes while the FAST 90mm (manual cable) is preferred for Street Rod/Off Road applications. Corvette kits come with both 76mm or 90/93mm provisions via a billet adaptor that can be easily changed.
INLET TUBE
Whether it’s the stock 76mm or a 90mm upgrade, the Corvette throttle body is fed by an equally high flowing 93mm inlet tube that was flow bench tested, shaped and contoured for hood clearance, while totally eliminating any air flow restriction from the reduced tube height. It’s as good as it gets.
BOOST-A-PUMP™
The Kenne Bell BOOST-A-PUMP™ is the ever popular fuel pump voltage booster/regulator. It is the most practical and cost effective approach to increasing fuel pump capacity. The BOOST-A-PUMP™ has been successfully used by top Corvette tuners and builders for years. Doesn’t heat the fuel like big “full time” in tank pumps. Only adds fuel under boost and maintains correct voltage even with vehicle voltage/current fluctuations. The BOOST-A-PUMP™ produces enough fuel for 700RWHP. As compared to the Corvette pump used by others, the Kenne Bell BOOST-A-PUMP™ combo pumps a whopping 51% more fuel at 60 psi and 73% more at 80 psi (See Corvette Tech Tips). Our tests indicate the stock Corvette pump pressure drops off (not good). Easy to install. Simple 3 wire hook up. Uses stock Corvette pump. Note: The BOOST-A-PUMP™ is already in wide use on Corvettes.

PULLEYS
Billet steel pulleys are available in 6 rib 1/8” increments from 2.5”-4.12” and 8 rib in 1/4” increments from 2.5”-4”. This covers a boost range of 5-18 psi. For weekend drags etc., pulleys can be changed in a mere 4 minutes. No supercharger is more flexible. 1 psi higher boost requires approximately 1.5 octane, 2 psi = 3 octane, etc. 1° of ignition timing advance needs 3/4 octane, 2° = 1-1/2 octane, etc. (see “Jim Bell’s Supercharged/Turbocharged Performance Guide” http://www.kennebell.net/techinfo/general-info/jimbells-supercharged-perf-guide.pdf).

OILING SYSTEM
Supercharger doesn’t use engine oil. Completely self contained with a dipstick. No drilling and tapping the oil pan for oil drain lines.
BYPASS VALVE
Bypass valves are nothing new, but the Kenne Bell valet mode is. This is an exclusive feature no other supercharger company offers. It not only looks cool, but this billet external bypass valve system incorporates a valet mode that allows the valve to be locked open and eliminate boost. This prevents the overzealous Dealer employees, parking attendants, repair shops and your teenagers from “checking out” your coveted Kenne Bell supercharger boosted Corvette.

CALIBRATION
Although Kenne Bell kits offer huge performance gains at any rpm, the driveability and factory feel is retained. Kenne Bell does not rely on chip companies for our calibration. We’ve done 100% of our cals and tuning in-house since 1991 on our own vehicles. The tune is an integral part of our kit. Expensive “custom tunes” are not necessary or recommended (see “Do I Need My Kenne Bell Supercharger Kit Re-tuned” http://www.kennebell.net/techinfo/general-info/Supercharger_ReTuned.pdf). There are ONLY TWO - and ONLY TWO methods of tuning more power into an engine - ignition timing and air fuel ratio. There is no black magic or secrets here. Rest assured that Kenne Bell is perfectly capable of tuning the kits we design.
BOOST-A-SPARK™ (optional)
Any vehicle from 1976 up with electronic ignition has more than enough ignition for start ups, cruise, economy and even wide open throttle. However, they are definitely lacking when cylinder pressure is raised with a supercharger or turbocharger. The BOOST-A-SPARK™ is the Kenne Bell “mate” to the BOOST-A-PUMP™. It only requires 3 wires to install vs. dozens for a CD system and will fire plugs at even 30 psi and higher. And it’s even adjustable. Activated only under boost when ignition is most critical. Optional in Kenne Bell kits but highly recommended.









• Boost measured on output side of intercooler.
• 8 rib belt system recommended after 12 psi.
• All tests SAE corrected.
• Divide by .85 for engine dyno HP and torque.
• Test car was ‘02 ZO6 manual trans.
TEST 1 - Stock ‘02 ZO6 Vette with 22° timing, 11.0 AF ratio. See Test 3 for a direct comparison of equal tuning supercharged and naturally aspirated.
TEST 2 - Kenne Bell 7 psi kit with timing set at 18 for 91 octane pump gas.
TEST 3 - Kenne Bell 7 psi kit with more aggressive 22° timing and 11.0 AF ratio to compare equal fuel and timing tune. 4° timing is 24HP. This setup could be used for competition or weekend racing with higher octane unleaded racing fuel.
TEST 4 - Here we get some idea of the kit’s HP potential adding 1 psi of boost from an efficient supercharger has a huge effect on power output as seen in Test 4 vs. Test 3. 20HP (569 vs. 549) and 37 ft. lbs. (557 vs. 520) from a simple easy 4 minute pulley change from 3-3/4” to 3-1/2”. And you don’t need a big puller to change a pulley. Note: 1.5-2 octane is required to support 1 psi of boost.
TEST 5 - Add a 90mm throttle body and we see an instant 20HP with the same 3-3/4” pulley.
TEST 6 - A 90mm LS2 throttle body was added. With the 3-1/2” pulley (Test 4), we recorded 32HP (601 vs. 569). The Twin Screw loves it when inlet restriction is lowered. In this case, 3.7” Hg vs. 4.7" Hg.
We believe 601HP and 568 ft. lbs. of torque at 8 psi from a Kenne Bell supercharged ZO6 with a 90mm throttle body is impressive. And the supercharger is only turning 13,910 rpm. Check out that tire shredding torque curve and how THE POWER IS STILL CLIMBING AT 6500 where it hits the rev limiter. That’s proof the supercharger efficiency and boost is not “dropping off.” All that with a standard 7 psi 2.6L kit should make anyone “feel good” about their car. Only those who can’t offer it ask “Why would anyone want all that low and mid range torque?” At 601HP, we have probably pushed the safe limit of the rods and pistons. Future tests will be published on our built LS1, LS2 and LS7 engines. Kenne Bell is serious about the Corvette market. We’ll be around as long as there are Corvettes to supercharge.


RESULTS: MORE HP, LOWER PARASITIC LOSS, HIGHER BOOST, LOWER TEMPS
Note: This test was performed on the ‘07 Shelby Cobra as it is the only factory produced vehicle with the 122. At 23 psi, the 100% stock Shelby made 801HP!
Home | Superchargers | Accessories | FAQ's | Tech Info | Price List | Media | Test Vehicles | Company | Contact Us | Policies
Copyright © 2008 Kenne Bell, Inc. All Rights Reserved