2005 GS Chrysler 300 SRT-8

The aftermarket is flush with tuner parts for the Chrysler 300C. Sad to say, though, it seems as if one in three 300s in Los Angeles abounds with 22-inch spinner wheels, chrome, and a booming sound system. Nice, but where's the beef?

Tuners now offer mods for the 300C's robust 5.7-liter Hemi V-8, but frankly a pumped and juiced 5.7-liter barely matches the output of a stock SRT-8's 6.1-liter, so why waste your time? Rather, check the option box for the SRT-8 package, and you get 425 horsepower, a heavy-duty suspension, huge wheels and tires, massive Brembo-sourced disc brakes, a custom interior, and special bodywork. Add to the SRT-8 package a shot of aftermarket horsepower, and now we're talking.

GS Motorsports has several power packages for the SRT-8. We went for its standard meat-and-potatoes Stage 1 package, which delivers 140 additional rear-wheel horsepower over a stock SRT-8's. As with a goose bred to produce foie gras, the majority of GS's big power comes by way of force-feeding. Pressure emanates from a Paxton Novi 1500 centrifugal supercharger system ($5650) that produces 6psi boost. An air-to-water aftercooler chills the boost, while a billet external wastegate offers head-gasket protection in the event of a pressure spike. For smog compliance, the stock fuel injectors are aided by twin auxiliary injectors that fire only when boost hits. Custom software programming sends ignition firing cues to aftermarket spark plugs. A custom-made set of Kooks 1-7/8-inch headers vents the spent fumes to high-flow catalytic converters paired with 3.0-inch-diameter tubing and Magnaflow stainless-steel mufflers (the kit is $2495). The exhaust note is mellow for long hauls, but throaty enough to inform passers-by of the 6.1-liter's 550 pound-feet of torque.

Drop the hammer on the GS SRT-8, and you'll be treated to copious tire spin--good for grins but bad for quick launches. Careful throttle application yields 4.3-second charges to 60 mph. Even better is that, with four people in the car, A/C blowing, and a toasty-hot engine, the supercharged SRT-8 ties the quarter-mile time of a stock 300C SRT-8.