Horsepower. Heaps of it. Probably more than any reasonable person could ever use. Those are the sort of things Hennessey Performance Engineering’s become famous for since being founded in 1991.
And also turn-key hypercars.
The word alone makes you think of expensive combinations of bright metals, exotic composites, and formula-derived engines almost always of European descent. But Hennessey’s Guinness World Record-setting, 270mph Venom GT doesn’t come from Italy. And it wasn’t put together in Germany. Yes, the bones of the Venom GT—a Lotus Exige—are as American as Yorkshire pudding and Toad-in-the-Hole, but what remains of the British carmaker’s handiwork are just that: bones. That’s mostly because of the 7.0L, twin-turbo Chevy V8 that Hennessey slid into place, which is good for 1,244 hp, the carbon-fiber body work and wheels, the active aero, and the carbon-ceramic, six-piston brakes necessary to make it all come to a stop.
Founder of Hennessey Performance Engineering and creator of the Venom GT, John Hennessey’s long dreamed of creating his own hypercar. Sixteen years’ worth of making Dodge Vipers faster than they ought to be resulted in one of Hennessey’s own squashing a Bugatti Veyron in a 2007 Road & Track magazine shootout. The victory left the tuning entrepreneur wondering what might be achieved in a lighter chassis. A few years later and at just over a million a pop, and a total of 29 Venom GTs were scheduled to be made.
Today Hennessey specializes in big-power sports cars, like its HPE700 supercharged Mustang GT and Corvette Stingray packages and twin-turbo Ferrari 458 and McLaren 12C conversions, but its beginnings that were rooted in the small apartment-based business are much humbler. Nearly 25 years ago, John Hennessey was just a guy working in the environmental services industry, looking for a way to make his daily driver 3000GT VR-4 quicker than what Mitsubishi’s engineers thought it should be. A couple of larger turbos at higher boost pressure, a bigger exhaust, higher-flowing fuel injectors, and a reprogrammed computer left Hennessey with an extra 150 hp. The results were a class win at Nevada’s Silver State Classic, a record-setting run at Bonneville’s salt flats, and instant notoriety from the automotive press.
In between the GTs 3000 and Venom, Hennessey Performance Engineering has grown in spades—its most recent, 30,000 square-foot location positioned just outside of Houston and alongside its own quarter-mile dragstrip and road course at Lonestar Motorsports Park; the group’s even opened its own state-certified Tuner School where just about anybody who wants to learn how to think like Hennessey without two-plus decades of trial and error can do so in a hands-on environment. They may even end up with a job working at the famed tuning headquarters. Along the way, the company’s also become famous for tweaking just about any kind of car that’s worthy of being tweaked.
Like twin-turbo Dodge Viper packages that yield 1,092 lb-ft of torque and are, in large part, why you’ve heard the name Hennessey. A variety of systems are available for the V10-based roadster, the most impressive of which will have you driving away in a 9.7-second capable car that comes with a one-year warranty and doesn’t sacrifice much in terms of drivability.
Following Hennessey’s own 3000GT build-up, he expanded, offering his services to like-minded mid-1990s sports cars, like Toyota’s twin-turbo Supra and Mazda’s rotary-based RX-7. Soon enough Hennessey was contracted to give the same sort of treatment to a potential client’s Viper, which went on to become one of the first to compete in organized motorsports and earn media attention of its own. The rest is history, which includes a series of cars built for the likes of Jay Leno and all sorts of Chrysler executives who wanted the sort of Viper that Chrysler’s accountants and lawyers wouldn’t let them deliver.
The company hasn’t forgotten about its roots, either, that were embedded with cars like the 3000GT. Today, Hennessey offers engine programs for Nissan’s GT-R that put out anywhere from 650 to 1,000 hp, depending on the system, and has since expanded into Texas-sized power gains for all sorts of trucks and sport-utilities, even European cars.
No matter the make or model, though, one thing’s for sure: it’ll leave Hennessey’s headquarters with more power than you’ll likely know what to do with.

Words by Aaron Bonk