If you unleash this tuned Mercedes, make sure your life insurance is paid up

With 515 horsepower on tap, the Mercedes-AMG GT S makes for a pretty lively driving experience. Mercedes even built its own factory hot rod version, the GT R, with 577 hp and numerous aerodynamic and chassis upgrades. But even that’s not enough for some people.

German tuner IMSA (not to be confused with the U.S. motor sports body of the same name) created a truly monstrous version of Mercedes’ sports car. Its RXR One Super Gran Turismo boasts a staggering 848 horsepower and 738 pound-feet of torque, taking the AMG GT S well into supercar territory.

The RXR One Super Gran Turismo uses the same 4.0-liter, twin-turbocharged V8 as the stock AMG GT S, but IMSA extensively modified the engine. The V8 now features forged pistons, modified turbochargers, and a new air intake and intercooler, among other changes. The stock seven-speed dual-clutch transaxle was also upgraded to handle the extra power, and the car was fitted with a roll cage. That’s probably a good idea when you’re playing with over 800 hp.

The exterior is the perfect match for the nuclear weapon under the hood. IMSA’s body kit seems to borrow heavily from the Mercedes-AMG GT3 race car, and gives the RXR One Super Gran Turismo a properly aggressive look. The front bumper, hood, trunk lid, and rear spoiler are all carbon fiber. The car is also equipped with racing-style center-lock wheels, sized 12×20 inches in front and 12.5 x 21 inches in the rear.

IMSA claims the RXR One Super Gran Turismo weighs less than 2,866 pounds, making it about 761 pounds lighter than a stock AMG GT S. That gives the tuner car an impressive power-to-weight ratio of 654 hp per ton. IMSA did not publish any performance figures, but we imagine the RXR One Super Gran Turismo will beat its stock counterpart’s 3.7-second 0 to 60 mph time by a significant margin.

IMSA plans to build a limited run of the RXR One Super Gran Turismo, although the company did not say exactly how many cars it plans to make, or how much they will cost. Anyone thinking of buying one of these monster Mercedes should factor a generous budget for tires and life insurance into the final cost, though.