INTERNATIONAL LAUNCH: Mercedes-AMG GT R is a star of engineering and a project of passion
Porsche’s 911 GT3 dominates the big end of track-day town and its adherents are unshakeable. AMG shot its GT and GT S straight at the heart of the 911, now it is going after the 911 GT3 with the GT R which is due in SA in the second quarter of 2017.
And its aim has been surgically precise. It’s a solidly stiff road car but an incandescent track car that sounds like an entire Nascar field.
Porsche used to have this market all to itself. You could spend a bit less and get a BMW M3 of one sort or another or spend a bit more for a near-pure track car, but to get something you were happy driving home again, you had to get a 911 GT3.
You don’t have to get a 911 GT3 anymore. In fact, you’d be almost legally culpable if you didn’t have a drive of one of these things before you turned up at Porsche with a cheque.
The GT R takes everything from the GT and GT S programmes and makes it stronger, lighter, more powerful and more precise. Everything from a 57mm stretch in width to how it steers to how it bites at the road to how it makes the airflow massage, it has all been changed. And it’s all been changed to make it go faster, everywhere, all the time.
It’s not hard to tell this one was a passion project at AMG, which brought its GT racing engineers and aerodynamicists into play right from the start. Everybody from boss Tobias Moers to the lowliest apprentice has been asked for their ideas to make the GT S faster and too many dinners were left cooling on family tables as they sorted through them and nutted out the details.
Of course, AMG didn’t neglect the engine. The dry-sumped 4.0l twin turbo V8 has 430kW of power and 700Nm of torque, which sprint it to 100km/h in 3.6 seconds.
That’s only a tenth quicker than the GT S (and 0.2 seconds slower than the family man’s E63 S) but the real reason the GT R exists is that this car is more than 20 seconds faster than the GT S around the Nürburgring’s Nordschleife circuit. With an independent German magazine clocking 7:10.9, it’s the new holder of the production road car record.
That doesn’t happen with just a bit more power. It happens with a bit more everything.
They’ve taken out weight with things like carbon fibre front wings, propshaft and the torque tube to the rear-mounted transaxle, but they’ve also put weight back in with rear-wheel steering and a host of carbon fibre reinforcements, so the net gain for the 1,555kg car is only 15kg.
Then there is the stance, which is wider by about 5cm at both ends, sitting on new coilover springs and dampers, with custom-developed settings, plus a cool nine-step adjustable traction control, which only works in the Race mode when the skid-control is turned off.
Then the aero coves joined in, adding a flat, carbon fibre undertray behind the fixed splitter that drops down 40mm to create a venturi effect above 80km/h in Race mode (or 120km/h in girlier modes). It reduces the front end’s lift by 40kg at 240km/h, though its work is added to by a set of louvres that open and close to change the car’s downforce levels to add grip in corners and reduce drag on straights.
There’s also a massive double diffuser at the back; the primary job is to use underfloor air to suck the back end onto the ground, while the second part borrows an idea from the Braun Formula 1 team to do the same thing with redirected radiator-cooling air. There’s also an adjustable rear wing and besides all of these pieces reducing lift all over the car (don’t believe anybody who tells you they give the GT R "downforce" because they don’t), they actually reduce its overall drag.
It gets bigger boots, with 275/35 ZR19 front and 325/30 ZR20 rear tyres, while implausibly light alloy wheels and carbon ceramic anchors are both optional and save another 4kg of unsprung mass per corner.
Yes, this car is the five-alarm chilli of the AMG world and, combined with the E63 it’s just launched, it clearly represents a turning point for a company that could have easily slipped into building profit-rich, mildly warm versions of all the Mercedes-Benz production cars and SUVs.
This is AMG at its most focused, more surgical than it has ever been, producing a car that’s neither the most expensive nor the most powerful it’s ever made, but easily the most precisely targeted.
It has all the usual built-in multimedia niceties of the stock GT, including navigation, a Burmeister sound system, air conditioning, a head-up display, connectivity for smartphones and a seat choice between electric sports seats and lighter manually operated hard-core sports seats.
There’s even a track pack, with a half-cage behind the front seats (which can be painted in the body’s colour), a four-point harness and even stickier tyres.
The thing is, it’s hard to know which of these areas stands out the most.
It’s obvious while it’s sitting still, though. Static, the star is the engine and, more specifically, how all that burnt air works its way out the back.
It’s loud from the inside, louder from the outside and it’s loud in a way that makes the very word "loud" seem inadequate. And that’s in the default start-up mode (Sport, incidentally).
It’s deep, it rumbles, it has a slightly odd, off-beat burble to it and the tacho needle responds to the throttle like someone jumped on the other end of it.
For all that, the engine is perhaps the least fiddled bit of the car. The modular V8 is dry-sumped, like it is in the GT, but runs different mapping, a slightly higher compression ratio and more turbo boost (up to 1.35 bar) to thump out an extra 55kW. To give it more agility, the dual-mass flywheel is 0.7kg lighter,
The seven-speed dual-clutch gets a taller first gear, a shorter seventh and a shorter final-drive ratio, while the rear diff is now so tight that ours graunched on full-lock turns.
The critical new addition, overlooked in favour of sexier aero talk, is the active rear-wheel steering, governed by a massive electric motor on each wheel and moving the toe angle up to 1.5°, with no physical connection to the steering wheel whatsoever. There are also uniball bearings on the rear, which don’t change their toe angle under hard cornering and are harder wearing than wishbone bushes.
So that’s just scratching the surface of what AMG has done to turn the twitchy GT S into the brilliant GT R. And it is brilliant.
The Black Series was the most precise of the old SLS coupes and it’s the same here. You have to put a lot of effort into driving a GT S quickly, but you get more reward, for the same effort, in the GT R. It’s also now just fast enough that you physically feel like you’ve had a workout after an afternoon of fast lappery.
How fast is it? Realistically, it’s lets-sit-down-and-recalibrate fast. It’s properly fast. It’s scorchingly fast. It’s not sneaky fast. It’s not sneaky anything.
Definitely not the kind of car that flies under the radar (the noise alone takes care of that), the GT R succeeds both on sheer speed on a circuit and it delivers a huge leap on giving the driver an experience to soak up and enjoy.
It starts, as every AMG does, with the engine note. The titanium exhaust turns its work into something that, in Sport+ or Race mode (or when you just push the Loudenator button) is so loud that just five of the things together would frighten off an alien invasion.
It’s an astonishingly brutal noise that is deeper than anything of just four litres has a right to be, yet rich, thick and carries an underlying sophistication to it. Then you lift off or brake and downshift and the pops and crackles are so exaggerated they make the just-launched, very loud E63 seem like it’s scrunching up a bit of paper by comparison.
And it matches that theatre with epic performance. Sure, 3.6 seconds to 100km/h is only a tenth quicker than the stock one, but that’s missing the point.
It’s belligerently flexible, with the torque peak hitting at only 1,900r/min and it’s belligerently loud while doing it. If it’s not just Porsches it’s chasing, Ferrari, Lamborghini and Aston are all incapable of making noise like this.
If you’ve driven 50m and still overlook just how much more precise the car is, then you’ve got no business driving it. It’s wasted on you.
The new carbon fibre braces, joining the underbody sides to the torque tube, give it an extra 7% of torsional rigidity. The torque tube itself adds more rigidity, so do a host of other braces. And the car is just astonishingly accurate now.
Too accurate, to be fair, on public roads. We found wet roads and mud all over the mountain passes of the Algarve in Portugal and the ride was at least firm in every mode, with the car snapping into wheelspin over muddy patches even in fifth or sixth gear with modest throttle inputs and little suspension compliance to help out.
On really bad roads, well, it might be just too hard for some people.
Where the GT S’s steering feedback suffers from its cab-rearward stance, the GT R is pin sharp and more intuitive. It still slides and it still runs out of grip, but it’s phenomenally easy to control, even with the traction control turned off completely.
To be safe, you can run it in Sport+ or in Race with the skid-control either on or in Sport mode. That way you keep some traction control plus some skid-control when the car starts to slide.
The fun way is to attack it in Race with the skid-control off all the way (hold the button down for five seconds), then you control the slides with your feet and hands and you control the traction control with the unmistakable bright yellow knob beneath the air vents.
It will light up as you turn it (with a mirror version in the dash display, in case you missed it) and it will light up the rear tyres more as you turn it down to off. There are nine stages, with the first for wet driving, the last for off and then there’s everything in between.
The whole package adds up to a machine that’s a joy to drive, all the time. You attack corners deeper and deeper under brakes because it bites and bites and bites.
You fiddle with the front end in fast and slow corners because it will dive hard for the apex even if you’ve still got a rude amount of friction squeezing the brake calipers together.
And you jump on the throttle harder and earlier, every lap, because the rear end (which has 52.7% of the weight) is simply accepting all the power you’re giving it and punching the car forward, harder and harder.
It works the other way, too, with an innate ability to pivot around the centre of its axis that’s highly sought after and rarely found, along with responding to throttle lift-offs sharply and precisely to bring the nose closer to the apex on both fast and slow bends.
It’s also almost infinitely adjustable in a corner and you can drive it on understeer or oversteer, you can drive it leaning on the back wheels or the front and you can fling it into high-speed four-wheel drifts at will, even over sharp camber changes and crests.
It is equally happy and able to drive it cleanly to set lap times or loosely to hang out and have a blast and it is more accurate to the touch than any Benz-badged road car in history.
At one point, with the stickier boots on, we were emerging onto Portimao’s front straight at 200km/h and braking at the end at well over 290. Sure, it can slide, buck and dance over bumps and hard cornering, but it leaves you with the unshakable impression that it’s dancing to the driver’s tune and the driver’s tune alone.
There will be a day when it lines up head to head against the 911 GT3 and even the GT3 RS and the McLaren 570S, but there are plenty of reasons to like it, even in that company.
That, and it’s also front-engined and rear-drive and happy to slide. And that never hurts.
Mercedes-AMG GT R
On sale date: Q2 2017
Max power: 430kW
Max torque: 700Nm
Top speed: 318km/h
0-100km/h: 3.6 seconds
Combined consumption: 11.4l/100km
CO2 emissions: 259g/km
Star rating out of five: ****.5