The 2015 Ford Mustang is yet to reach showrooms but the people at Whipple Superchargers have already developed a 700-horsepower upgrade for it, according to a leaked press release. This has likely been made possible because the upgrade is designed for the 2015 Mustang GT, whose 5.0-liter V-8 is a carryover from the outgoing model.

The upgrade consists of a 2.9-liter twin-screw supercharger, which is said to have 99 percent volumetric efficiency and is designed to be installed with very little modification to the engine. The upgrade also includes an air-to-water intercooler, high-flow fuel injectors, a high flow intake and exhaust system, and retuning of the ECU.

Ford claims its new Mustang GT will have roughly 420 horsepower on tap, meaning Whipple’s upgrade adds 280 horses to the tally. But it’s not all about peak power as Whipple says the supercharger has a “discharge down” design that gives more power at lower boost levels and a relatively flat torque curve. The setup is also said to be quite efficient, as it consumes less than a horsepower during cruising.

No performance estimates have been mentioned, but the upgrade should deliver better numbers than the previous Mustang Shelby GT500, whose supercharged 5.8-liter V-8 was turned to deliver 662 horsepower. That’s because the new Mustang is lighter than the one it replaces, and the Whipple upgrade has the power advantage.

Further development of the upgrade is planned, with Whipple promising to release cold air intake and throttle body kits for the 2015 Mustang as well.

Note, Ford is also thought to be developing its own supercharged version of the 2015 Mustang. Prototypes for the car have already been spotted, and a debut is expected either this year or next.