We could go on for many times the normal length of this section explaining exactly how Mercedes-AMG has tweaked and transformed the ‘ordinary’ GT super-sports car to turn it into the GT R.
Its efforts vary from the predictable to the ground-breaking and include some deliciously purposeful modifications to the car’s engine, transmission, chassis and suspension.
The headline news is that the GT R is 15kg lighter than the standard GT S (although that is an advantage you can double if you select AMG’s carbon-ceramic brake option), yet it has a wider body than the GT S and also a reinforced chassis that is significantly more rigid.
The R also benefits from key technologies, many of which have never been seen on any AMG before, that each increase grip, performance and handling dynamism.
Carbonfibre wings extend the car’s width by 46mm at the front, while matching sheet metal extensions add 57mm over the rear wheels – both in order to cover significantly wider axle tracks.
Carbonfibre is also used for the roof panel, in various places under the body and bonnet to brace the superstructure and also for the car’s ‘torque tube’ propshaft.
Suspension is via adjustable coilovers and adaptive dampers. A thicker anti-roll bar than the standard GT gets features at the rear, where ‘uniball’ mountings are also adopted in place of normal bushings for enhanced handling precision and control feedback. Forged aluminium is used for the car’s wishbones, hub carriers and steering knuckles, all to reduce unsprung mass.
The 4.0-litre twin-turbocharged V8 engine from the GT S gets new compressors, wastegates and exhaust ports, as well as an altered compression ratio and a tweaked ECU, to produce 577bhp and 516lb ft.
The engine drives the car’s rear wheels (through that lighter, stiffer propshaft) via a transaxle gearbox with a shorter final drive, a longer first gear and a shorter seventh gear than those used by the GT S.
Active aerodynamic features include an underbody aerofoil that automatically extends 40mm downwards at high speeds, creating a ‘ground-effect’ venturi under the front of the car and reducing front axle lift by 40kg at 155mph. It retracts again at low speeds to guard against kerb and speed bump damage.
The GT R is also the first Mercedes-AMG to feature active rear-axle steering. The system, which is similar to the one used by Porsche and BMW, applies up to 1.5deg of toe angle working against the direction of the front wheels at low speeds and with them at higher speeds.