The muscle car era was full of legendary big-block engines. Chevy had the L88 and LS6, Pontiac had the Ram Air and Super Duty motors, while Ford countered with Clevelands and Cobra Jets. All of these nostalgia motors have earned a place in history but none have garnered the notoriety of the Chrysler Hemi. The name Hemi has become synonymous with performance, from its original inception right through to the age of electronics. This fact obviously did not escape the marketing department over at Chrysler, as the Hemi namesake was given to the most recent version of Chrysler's performance offerings. Though it can be argued whether the modern, injected Hemi is actually a true Hemi, there is no denying the impressive performance offered by the current combinations, especially those sporting the SRT8 insignia. Time and technology have marched on since the original Hemi, but the modern 6.1L SRT8 motor is every bit as powerful as the legendary (and much larger) 426 Hemi. That same technology has allowed the modern Hemi to offer not only exceptional acceleration, but a combination of performance, mileage, and emissions unheard of during the days of the original Hemis.

Despite the performance potential of the factory 5.7L and 6.1L offerings, enthusiasts being enthusiasts, they always want more. Lucky for us, more is almost always available, even for Chrysler's latest bit of nostalgia, the impressive Hemi-powered Challenger. As with the original, the injected Hemi responds very well to the usual assortment of bolt-ons, including ported heads, cams, and even stroker-based displacement changes. Heck, it is even possible to bore and stroke a modern motor out to equal the displacement of the original 426. While bolt-ons offer plenty of potential, many run afoul of current emissions regulations. Those that have received compliance usually offer only minor performance gains, air intake and cat-back exhaust systems being the most popular. For those Hemi owners looking for some serious power gains without fear of local law enforcement discovering their "off-road only" components, look no further than a Kenne Bell supercharger. Unlike some of the other available supercharger kits that offer just 5 psi, the Kenne Bell supercharger kits for 5.7L and 6.1L Hemi-powered vehicles will be certified at a full 8 psi.

We followed along while the guys at Kenne Bell installed one of their Hemi supercharger kits on a new Challenger. In fact, they installed kits on a pair of Challengers, one automatic and one stick, making a comparison between the two all but mandatory. The photos cover some of the installation shots, but know that with an installation manual that spans 158 pages, it would be impossible to cover every detail. The highlights obviously include the Kenne Bell twin-screw supercharger. Offered in both standard and high-boost H-series, the twin screw supercharger displaced 2.8 liters. It is important to point out that the 2.8L H-series blower is capable of supporting over 1,000 hp (with dyno results to back up the claim), so it will have no trouble feeding a stock or modified Hemi motor. In fact, it is reassuring to know that if you install the blower on your stock motor, it has the capacity to grow with your power needs should you upgrade to ported heads, cam or even a 426 stroker motor at a later date. Compared to some of the smaller blowers on the market, the Kenne Bell twin-screw 2.8L offers an impressive combination of efficiency and airflow, making it equally effective on both stock and modified motors.

When it comes to producing an effective supercharger kit, there are a number of details that make or break the kit. Supercharged Hemi performance is not simply a matter of installing a blower and calling it good. For the blower to perform optimally, both the air and fuel flow must be optimized. While some may argue that the blower adds all the air the motor can use, the reality is that superchargers, especially positive displacement superchargers, are ultra sensitive to inlet restriction. Restricting the air going into the supercharger will result in a drop in airflow (and boost) going out. Potential restrictions include everything positioned in front of the supercharger, including the blower inlet manifold, the throttle body, air intake tube, and filter assembly. It goes without saying that every effort should be made to provide a cold air source for the system, but the airflow rate of these other components must also be optimized. The blower experts at Kenne Bell are well aware of this problem and have made every effort to maximize the flow rate of the inlet system. Their changes include a dedicated Mammoth blower intake manifold that flows a whopping 1,500 cfm and a 4.5-inch air intake tube and an open-element filter that exceeds 2,000 cfm. The limiting factor in the air intake system in terms of flow is actually the stock 81mm throttle body that flows only 924 cfm.