The World Endurance Championship and F1 are still the undisputed kings of global motorsport, but GT4 racing has developed into an interesting battleground for supercars with aero kits, slick tires and roll cages. The latest road-going exotic to make the jump to FIA GT4 is the Mercedes-AMG GT R.
Launched at the 24-hour race at Spa, the AMG GT4 turns the (already focused) AMG GT R road car into a fully-formed entry into the world of competitive racing. Although there's a lot of clever performance technology going on here, the biggest tweaks between road and race car come down to safety. The GT4 is fitted with a high-strength steel roll cage, and the driver sits in a carbon safety cell that meets the latest FIA homologation standards.
The carbon seat is HANS (a standardized protection system designed to prevent neck injuries) compatible, and there's an inbuilt fire extinguisher system, while a hatch built into the roof makes it easier to extract an incapacitated driver. All of this might sound boring, but it's a non-negotiable when you're racing wheel-to-wheel at high speeds.
As it does in the road car, power comes from a twin-turbo V8 making around 503 hp (375 kW) and 600 Nm (443 lb-ft) of torque. Final outputs will change based on the FIA's Balance of Performance rules, which aim to deliver tight racing by adjusting each car's power output throughout the season. The engine is hooked up to a pneumatically-operated six-speed sequential gearbox, and power is put to the road through a fully adjustable rear differential.
The most noticeable of the changes – from the outside, at least – is the GT4-spec aerodynamics kit. The front bumper has a broad, low air intake and there's a new scoop in the bonnet to feed the hungry V8 engine. Down back, the road GT R wing has been turfed for a bigger unit, and the broad diffuser has more of an edge to it. The GT4 looks properly mean, basically, and produces more downforce in the process.
If the extra downforce on offer isn't enough, the GT4 rides on a unique suspension as well. The double-wishbone setup is coupled with dampers that are adjustable for rebound and compression, in the hopes of delivering a driving experience that develops as drivers advance their skills. The amount of assistance on the anti-lock brakes can also be adjusted.
The further you dig, the clearer it becomes that adjustability and accessibility are at the core of the AMG GT4. Along with the ABS and dampers, the traction control system can be toggled through 11 different levels of assistance depending on conditions, which is perfect for drivers who are still learning the ropes on the track.
All of this user-friendly raciness doesn't come cheap. You'll pay €198,850 (US$231,500) for a GT4, and that doesn't include the extra tires, fuel and support you'll need to run the car in a professional racing series. It's also significantly more expensive than the Porsche Cayman GT4 Clubsport, so the AMG would want to be good.