The 6 pounds of boost heaving into the 6.2-liter LS3 are enough to swell output from the stock 426 horsepower at the crank to a monstrous 562 hp, according to Mr. Hennessey. On the Dynojet chassis dyno at MD Automotive, however, the HPE550 ripped the rollers to the tune of 559 hp at the wheels.

At the test track, the blast from zero to 60 mph took a deliriously brief 4.3 seconds (4.0 seconds with 1 foot of roll out like on a drag strip) and the quarter-mile blurs by in just 12.1 seconds at 120.1 mph. It's an absolutely scalding performance and it's a full four-tenths quicker to 60 than a stock Camaro SS and nearly a full second quicker in the quarter-mile. Most impressively, that 120.1-mph trap speed is 9.2 mph faster than stock. Zounds upon zounds, this thing is rapid.

Source: Edmunds