“BIG BORE” CONCEPT (2L, 3L)
These big displacement billet beauties simply overpower the competitions Eaton Roots style 1.5L (90), 1.83L (112), 2.0L (122) and TVS (2.3L). These are the most powerful positive displacement 2L series superchargers that are practical for underhood installations. The BIG BORE superchargers are the ideal choice for stock, street, street rod, off road and competition engines. Kenne Bell is also the leader in replacement Twin Screw upgrades for the ‘03 Cobra and ‘99-’04 Lightning and, the latest ‘07 up Shelby GT 500.
Modern day under hood applications have space limitations. The supercharger must fit between the firewall and radiator and - along with the pulley - clear the stock hood, yet supply enough air to support the higher HP demands of the new Hi-Tech Ford, GM and Chrysler engines. That requires an extremely efficient, big displacement, compact and lightweight supercharger - the Kenne Bell Twin Screw 2L, 3L, 4L series.
The BIG BORE superchargers were designed to satisfy the ever escalating HP and/or displacement demands of the latest Ford 4V, 3V, 2V, GM LS1, LS2 and 7.0L - and Hemi 6.1-7.01L - up to 1400HP.These engines continue to make more power in naturally aspirated form. Therefore, larger more efficient superchargers are needed to keep up with the new technology. And if your application doesn’t require the full HP potential of the larger displacement BIG BORE supercharger, you are still ahead because the Kenne Bell uses less rpm with lower parasitic losses to develop the same boost as smaller superchargers. Lower rpm also means reduced heat, friction and wear with quieter operation - all in an intimidating hi-tech billet package that fits under stock hoods.
The BIG BORE design is similar to the proven short stroke big bore high RPM engine designs. Take a tried and proven product with a reputation for outstanding performance and make it “bigger,” more efficient and more powerful. These larger diameter 4x6 lobe rotors pump a LOT of air, yet the billet case “length” is comparable to others. The re-designed rotor profiles (6 female lobes-4 male lobes) reflect the latest in rotor technology i.e. cooler air charge temps, lower parasitic loss and increased air flow with lower rotor speed. Durability? We stayed with the same race proven construction that got us here - 100% billet, oversize bearings and shafts, precision Italian made gears and CNC ported inlet and outlet plates.
We designed the largest diameter rotors possible and adjusted the case length to achieve the various displacement ratings (4.2L, 3.6L, 2.8L, 2.6L, 2.1L). Except for case and rotor length and the inlet and outlet porting, the BIG BORE supercharger families (2L and 3L-4L) are basically identical in both construction and componentry.
PULLEYS / BOOST / HP COMPARISON
When compared to other superchargers with the same pulley size, expect big boost and HP gains. The BIG BORE offers higher air flow with the same rotor speed, so it produces more boost and HP at any rpm - or the same boost as others with a larger pulley. Example: The 2.8L will make 18.5 psi (+10 psi) vs. 8.5 psi for the biggest Eaton 122 on a stock ‘07 Shelby GT 5.4 4V - and 6 psi more boost than a 2.3 Twin Screw or TVS 2.3. Reduce the 10 rib pulley size from 2.92” to 2.5” and the 2.8L makes yet another 5 psi (23 psi). All with the STOCK crank pulley.
BELT CONTACT PATCH
Maximum supercharger belt contact patch is a must if belt slippage, wear and loss of power are to be avoided. The BIG BORE simply turns less rpm to develop the same boost so it uses big “no slip” billet steel pulleys up to 1” (4” vs. 3”) or 33% larger in diameter. This means 33% more belt contact, the equivalent of upgrading a 6 rib to an 8 rib - without the high cost of an 8 rib upgrade kit or oversize crank pulley or a cog belt system. 25% larger 8 rib = 10 rib and 20% larger 10 rib = 12 rib etc.