AMG is a longtime purveyor of excess horsepower, but its greatest strength still lies in its engines, however, here taking the form of a twin-turbocharged 4.0-liter V-8. At 577 horsepower and 516 lb-ft of torque, the GT R’s dry-sump powerplant produces 74 horsepower and 37 lb-ft of torque more than the GT S model. Boost, which increases from 17.4 to 19.6 psi, is a big part of that equation. A drop in compression from 10.5:1 to 9.5:1 helps accommodate the boost increase. The two BorgWarner turbos housed in the engine’s valley get bigger compressor wheels, and the cylinder heads’ exhaust ports are milled to improve flow. But the engine changes are just the beginning.

The transmission remains the same basic seven-speed dual-clutch automatic used in the GT and GT S models. It’s a relatively compact transaxle that incorporates an electronically controlled limited-slip differential and is located between the rear wheels. In the GT R, however, its ratios are altered; first gear is taller, seventh is shorter, and the final drive is shorter as well, changing to 3.88:1 versus the GT S’s 3.67:1 ratio. The result overall is a taller first gear—the goal was that it could now be used in tight corners—and shorter ratios in second through seventh. Stealing a trick from Porsche, AMG cuts fuel delivery while keeping the throttles open to avoid stalling the turbos when the driver lifts off the accelerator. The transmission bangs between gears with zero hesitation and satisfying popping sounds on downshifts.