Because they turn less rpm to develop the same boost, the larger displacement Kenne Bell BIG BORE Superchargers simply 1) make more boost, 2) produce more HP & TQ, 3) consume less engine HP to drive, 4) supply cooler denser air to your engine, while 5) reducing supercharger heat and wear.

Above is the 701HP Kenne Bell Supercharged/Intercooled LS1 that was installed in Larry Weiner’s Performance West ‘59 Chevy Sedan Delivery Street Rod. The engine was built and dyno tested by Turnkey Engine Supply in Oceanside, California. The LS1 features Air Flow Research heads and cams, FAST 90mm throttle body, Turnkey Stand Alone System, 62lb injectors and Kenne Bell BOOST-A-PUMP™. 8.1 compression ratio allows use of 91-94 octane pump gas for daily street or off road use. Boost and HP can be increased further with higher octane race fuel for weekend racing. Torque? Try 670 ft. lbs. at only 2000 rpm. And it still had 600 ft. lbs. at 6000 rpm! Think you’ll feel THAT fat, flat torque curve? The 2.6L supercharger has a power potential of 950HP. Higher boost and/or larger engines are capable of producing even more power. Up to 1000HP with the 2.8L.

• “Big Block” feel at any engine or vehicle speed, not just peak rpm.
• Instant full boost / HP & Torque at any rpm - 2500 up.
• More low and mid range torque and HP because it makes more boost there.
• Highest HP potential (up to 1000HP*), yet extremely “streetable.”
• No boost “drop off” from 5-18 psi*.Huge 93mm inlet manifold accepts stock 76mm or aftermarket 90mm throttle body.
• 93mm matching inlet system (molded plastic tube and filter). Not included with Street Rod/Off Road Kits.
• Traditional top mount - front facing design.
• Twin Screw efficiency (cooler air charge temp, lower parasitic loss).
• Billet aluminum construction.
• Quick and easy 4 minute pulley changes (5-18 psi).
• Both 6 rib and 8 rib pulleys available.
• Self contained oil supply. No drilling holes in oil pan. No oil lines.
• Doesn’t use oil from engine for supercharger.
• Whisper quiet.
• Looks factory with same driveability as stock.
• Billet fuel system, 42lb injectors (62lb optional) and Kenne Bell BOOST-A-PUMP™.
• BOOST-A-PUMP™ eliminates replacing stock pump.
• Bar and plate intercooler - more efficient than tube and fin.
• “Two Pass” heat exchanger.
• Serviceable. Supercharger can be rebuilt.
• Polished or black satin.
• Step by Step Detailed Instructions and Tech Tips.
• Kit includes all gaskets and hardware.
• All major components assembled and ready to bolt on engine.
• Includes hood (Corvette only).

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

Kenne Bell is a family owned hi-tech supercharger company rich in high performance engineering heritage and well experienced in factory direct sales and service. In 1991, when we introduced our new Twin Screw kits to the Ford market, we adopted the policy of selling factory direct to our customers. It’s worked very well for us over the years. Eliminating the “middleman” (Auto Dealer, Distributor, Web Sellers, etc.) profit allowed us to keep our supercharger prices more competitive. Since all engineering, calibration, testing, marketing, assembly, warehousing, direct sales, tech support, warranties, etc. are handled in house at Kenne Bell - we have no use whatsoever for any other middleman services. Who knows Kenne Bell superchargers, the applications and the technical issues better than us? For those who require installation service, we have a network of Authorized Kenne Bell Installers. Check with us for locations.

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 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.”

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.

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.

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
Flash Tuner

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.

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.

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.

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.

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.


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.


Kit comes with all necessary components including billet fuel rails, billet fuel block and 42lb injectors capable of 560RWHP. Optional 62lb injectors are rated at 800RWHP. The Kenne Bell BOOST-A-PUMP™ supplies the additional fuel pump capacity. The Kenne Bell OPTIMIZER™ is calibrated specifically for the injectors, pump capacity, HP, transmission type (auto or manual) etc. No “custom tuning” is necessary for our standard kits.

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”


Huge 14”x5.5” intercooler is same design used by Roush, Ford Cobra, GT, Lightning and Kenne Bell Mustang, Hemi and GM kits. Our tests indicate the bar and plate to be more efficient than the tube and fin design. The big heat exchanger is a “Two Pass” design. Kits are complete and include pump, reservoir and all hardware.

Supercharger doesn’t use engine oil. Completely self contained with a dipstick. No drilling and tapping the oil pan for oil drain lines.

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.

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” 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.


Knowing full well how important hood design and appearance was to Corvette owners, we spent considerable time with customer feedback. Kenne Bell Tech Director Ken Christley, who has owned 4 Corvettes, gave the final O.K. He’s probably biased, but he insists it’s the best looking hood out there. The Kenne Bell designed hood, with a little help from GM, is produced by RK Sport exclusively for Kenne Bell. We own the tooling. It is included in the kit price. The hood, which mimics the stock Corvette, has been referred to by the media as arrogant and intimidating, yet subtle enough at first glance to look stock! The scoop is higher to accommodate the front facing supercharger - but the height is about the same as other supercharger hoods (see photos). This hood has come to symbolize Kenne Bell Twin Screw Supercharger performance. We now have customers ordering the hood who don't even own a Kenne Bell Supercharger.

The past. Since the 50’s, the raised or scooped hood clearly signified “supercharger” or something big, powerful and intimidating. One would have to be living in a cave to not be aware of the trend toward positive displacement superchargers. The future. Rest assured, that the new supercharged $100,000 Corvette will sport a distinctively different and raised hood that wraps around the new supercharger. It should be very similar to the Kenne Bell kit. Why? A supercharger stacked on top of an intercooler simply cannot fit under a “typical stock” low slung sports car hood. The top mounted positive displacement supercharger is here to stay. It’s the present and the future because it is a clean, simple, compact power adder that looks like it BELONGS on the GM engine. And it delivers full boost (HP and TQ) on demand at any and all engine speeds.

Ken Christley’s 601HP 5.7. 550-569 ft lbs between 2000-6500. Black satin 2.6L.

Jeff Gooss’ 6.6L. 801HP/855 ft lbs (800 ft lbs @ 2500 rpm). Optional polished stainless 97mm inlet tube. High boost 2.8L.

Dave Tubbs ‘01 ZO6 5.7L 533RWHP - 480RW FT LBS - 7 PSI. Optional polished stainless 97mm inlet tube.

Under the intimidating Kenne Bell supercharged hood is the big 2.6L 900HP rated Twin Screw that’s just loafing at even 600HP. This is no OEM Roots style supercharger but instead, a race proven Twin Screw capable of up to 18 psi boost with no “boost drop off.” It’s fed by a huge 93mm high density plastic inlet and filter system that accepts either the stock 76mm or LS2 90mm throttle body. The external bypass system is open during normal driving conditions thereby “freewheeling” the supercharger and maintaining fuel economy.

Our goal at Kenne Bell is to always provide accurate and factual data, tests and tech info. We believe the information must be available in order to make intelligent decisions. These tests were conducted on an ‘02 ZO6 6 speed. The only mod was a cool air kit. It was tuned to 22° and 11:1 air fuel ratio to minimize comparison variables. Everything possible was done to guarantee test accuracy. Pay particular attention to the massive torque and HP at the various rpm points of the engine. Dynos measure torque and then convert the torque readings to HP. Torque is the twisting force that pins you to the seat and puts that grin on your face.

This is a comparison between two Kenne Bell customer cars, a yellow ‘04 ZO6 and an ‘05 Ford GT Supercar. Both were tested with 91 octane on the same dyno. Obviously, a Kenne Bell equipped Corvette can hold it’s own against the Ford GT, even with only a 7 psi kit.

To determine HP and TORQUE gains from 350HP, use 315RWHP instead of 367 and calculate with the % gains shown in table. Example: Use TEST 2 “Standard Kit” with 43% HP increase: 1.43 x 315 = 450RWHP vs 525RWHP for the ZO6.

• 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.


How does the latest Eaton 122 (2.0L) Roots type, which is even larger than the Eaton 112 (1.85L), compare to the Kenne Bell 2.8L Twin Screw kit with the same 3” pulley, custom tune (23° 11.5 AFR), stock inlet systems, etc? To make 125HP at the same supercharger rpm, there must be something better about the Twin Screw. The Kenne Bell 2.6 and 2.8 are simply larger displacement more efficient superchargers that produce higher air flow, boost and HP - and they consume LESS engine HP to operate.


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!


Historically, hot rodders have preferred positive displacement supercharging because of the huge power and torque increases at any rpm - and the intimidating image they add to any vehicle. The old Roots style superchargers have been around for years, but as compared to the Twin Screw, they are relatively inefficient, noisy, bulky and heavy. The old carburetors were great, but today, cutting a big hole in the hood of a street rod to accommodate a supercharger - with or without a carburetor - is rarely acceptable. The trend is toward more compact, lighter, efficient (cooler air charge and less parasitic HP loss) and powerful Twin Screw superchargers on fuel injected engines. The smaller Roots style Eaton 90, 112 and 120 (1.47L, 1.83L and 1.97L) are excellent low cost OEM grade superchargers, but they are no match for the new hi-tech Kenne Bell Twin Screws. These race proven billet beauties can make 950HP on modern lightweight fuel injected GM engines. And you won’t get hungry or sleepy waiting for the boost (HP & torque) to build up.

Sand Car 700-1000HP Kenne Bell supercharged engines by Turnkey Engines. Fat flat torque curve and full boost at ANY engine rpm makes for the ultimate Off Road engine - supercharger combinations. Available for LS1, LS2, 7.0L and strokers.