The 2019 Chevrolet Corvette ZR1 represents the peak of the seventh generation of America’s sports car, and as such is the most extreme of the front engine Corvettes. From the factory the ZR1 boasted an incredible 755 horsepower and 715 lb-ft of torque, courtesy of the 6.2 liter supercharged V8 engine internally known as the LT5. That momentous amount of shove is sent to the rear wheels only via seven speed manual or eight speed automatic transaxle. While over 750 horsepower is more than enough for most drivers, John Hennessey and his team at Hennessey Performance decided to crank the knob up to 11.
Hennessey currently offers three different upgrade packages for the C7 ZR1: the HPE850, HPE1000, and HPE1200 kits. Like any kit that Hennessey sells, those numbers refer to the horsepower output available with each package. The HPE1200 therefore produces 1,200 horsepower and 1,066 lb-ft of torque on race fuel, gains of 445 horsepower and 351 lb-ft of torque over the standard Corvette ZR1. When you can’t get your hands on race gas, the HPE1200 kit promises to still produce 1,100 horsepower with 93 octane fuel.
In order to increase total output by over 50 percent, Hennessey Performance made some drastic changes to the engine, including porting the factory 2.65 liter Eaton supercharger and cylinder heads. Other upgrades include but are not limited to a billet high-flow throttle body, a Hennessey upper and lower pulley upgrades, as well as a grade high-flow air induction system and custom HPE camshaft. For owners who opt for the 8 speed automatic transmission, a transmission upgrade kit is required as well.
While the ZR1 was developed to take on the fastest road courses in the world, that didn’t stop Hennessey from seeing what their HPE1200 could do on the drag strip. In the video above, the Corvette ZR1 with the HPE1200 kit is able to knock off the quarter mile in 8.97 seconds at 156 miles per horsepower. That’s incredibly quick, particularly when you consider the less than ideal 102 degrees F* air temperature and a density altitude of 2,755 ft. The car was fitted with Mickey Thompson drag radials and was running 24 lbs of boost through the ported blower.
Hennessey offers no pricing information for their HPE1200 kit for the Corvette ZR1, but we do know that they offer a 3 year / 36,000 mile warranty.