For most of us mortal humans, the 526 peak horsepower made by the Shelby GT350R Mustang’s splendid 5.2-liter Voodoo V8 is plenty enough to keep us sated in pretty much any scenario. For the slender minority that demands more, there’s Hennessey Performance Engineering’s HPE850 package.
As the name suggests, HPE850 is meant to take peak horsepower in the Shelby GT350R (and standard GT350) from its stock 526 to an impressive 850 at the crank, translating to about 740 horsepower at the wheels assuming a standard 15% drivetrain loss. However, the folks at Hennessey have put out a video showing a recent dynamometer test where one example produces an incredible 787 rear-wheel-horsepower, which suggests a crank horsepower rating over 900.
Granted, Hennessey was careful to say in the YouTube comments section that “some of the other 350R’s we have upgraded don’t make quite as much power,” and that the company will continue to call the package “HPE850” even though “that power level is probably conservative.”
The HPE850 package bolsters output in the Shelby GT350R Mustang via a 2.9-liter Supercharger system with high-flow induction and fuel upgrades, and long-tube stainless headers with high-flow cats and mid-pipes. Hennessey claims a 0-to-60 time of 3.3 seconds, and a 10.8-second quarter-mile.