Dodge one-upped its main rivals when it introduced the 707-horsepower Challenger Hellcat. Ford and Chevrolet have yet to respond, so American car tuner Hennessey is taking the matter into its own hands with a hot-rodded Mustang that packs even more grunt under the hood than Dodge’s vaunted muscle car.

The HPE800 is based on the Ford Mustang GT, and it was designed to celebrate Hennessey’s 25th birthday. The tuner started with the GT’s 5.0-liter V8 engine and fitted it with a 2.9-liter supercharger. Other mechanical modifications include a high-flow air intake made out of carbon fiber, a revised fuel-delivery system, strengthened gaskets, and a sport exhausts.

All told, the eight-cylinder delivers 804 horsepower at 7,000 rpm and 648 pound-feet of torque at 4,400 rpm when it’s sipping 93-octane gasoline. The HPE800 hits 60 mph from a stop in just 3.1 seconds, and it goes on to a track-worthy top speed of 207 mph. Power is routed to the rear wheels via either a six-speed manual transmission or a six-speed automatic unit. Surprisingly, both transmissions are fully stock.

Bigger brakes sourced from Brembo and a revised, lowered suspension setup keep the extra power in check.

Doubling the Mustang’s output wasn’t enough for Hennessey. Visually, the pony car stands out thanks to a body kit that includes a massive front splitter, side skirts, and a trunk-mounted spoiler. It rides on 20-inch wheels wrapped by Michelin Pilot Super Sport tires, and it features an array of commemorative stickers and decals that tell onlookers they’re not following a run-of-the-mill ‘Stang. Inside, every HPE800 features custom floor mats, embroidered headrests, and a plaque engraved with its serial number.

Hennessey will build just 25 examples of the HPE800 in the coming months. It’s available both as a coupe and a convertible. Pricing information hasn’t been announced yet, but every one comes with a certificate of authenticity from Hennessey and a three-year, 36,000-mile warranty.