Mercedes-AMG does a GT R

Affalterbach locks on 911 GT3 RS with scorching new GT R

THREE years after the SLS Black Series departed, its angry baby brother GT R lobs as the next hardcore, track-focused AMG with its sights set (again) on Porsche’s 911 GT3 RS.

Affalterbach will charge around $400K for the GT R when it arrives locally in July 2017, placing it directly against broad competition beyond Stuttgart.

While the 4.0-litre twinturbo V8 unlocks 55kW/50Nm above a standard $300K GT S to 430kW/700Nm, and helps deliver a 3.6sec 0-100km/h and 318km/h top speed, this road-racer is about maximising the potential of its sticky Michelin Pilot Sport Cup 2s.

A total 15kg weight loss over the GT S is no Jenny Craig success story, but the 1555kg GT R ups torsional rigidity by 7.5 per cent.

This AMG’s ‘Green Hell magno’ paint gives a nod to the Nurburgring where a sub-7min 20sec is promised – at least 10sec quicker than SLS Black Series – thanks to a lightweight carbonfibre injection, chassis tech additions and F1-derived aero and traction control tricks, plus the extra grunt. Here are six changes to the definitely-unhyphenated-GT R and how it plans to sink its shiny chrome fangs into rivals…

AMG GT R

6 core strengths

1 ACTIVE AERO

Louvres and ‘air curtains’ flutter open behind wider front intakes to guide air through wheelarches and out rear diffuser, then shut to create a slipperierthan- GT S drag coefficient. Fixed wing isn’t active, but total aero pack means GT R also delivers an extra 155kg of topspeed downforce versus GT S.

2 REAR STEERING

Conventional rear control arms out, twin jackscrew-plus-electric motor actuators in. The ‘fly by wire’ system can pivot toe angle by up to 1.5 degrees, turning back rubber in the opposite direction to the steering angle below 100km/h to “virtually” shorten the wheelbase and increase agility.

3 MORE GRUNT

AMG claims a modified combustion chamber for the 4.0-litre V8 with new forged aluminium pistons, cylinder linings coated in F1-derived Nanoslide compound. New turbos allow boost to be cranked from 1.2 to 1.35 bar, the GT R gets a 0.7kg-lighter two-mass flywheel and its dual-clutcher scores a longer first, shorter seventh and quicker shifts.

4 TRACTION CONTROL

A rotary dial sits beneath the GT R’s front air vents with a band of nine LED lights informing the driver of each change in permissible slip angle – from level-one wet and least rear wheelspin, to levelnine dry and much back rubber burn. It works independently of AMG’s threemode stability control that gets an ‘ESCOff’ pinched from the GT3 racer.

5 FAT STYLING

Just call the GT R a three-quarterstrength GT3 racer. Front (now carbonfibre) guards swell by 46mm, the rears by 51mm and capping the new magnesium front deck is a 300 SL-inspired 15-fin ‘Pan Americana’ grille.

Wider tracks house forged alloy wheels and yellow-licked brake calipers.

6 WEIGHT DROP

Rear weight bias moves from 47.3 to 52.7 per cent. Cast in carbonfibre are the powertrain tunnel (40 per cent lighter than aluminium GT S), under body/ bonnet bracing (50 per cent lighter than steel), front wings and roof. Titanium exhaust sheds 6kg.