While GT3 is now very much targeted at the sports car racing elite, its junior sibling provides serious performance for the slightly less committed. And Mercedes has just stepped into the GT4 arena
Just because progress is unstoppable, that does not mean it is always in the right direction. I bow to no one in my admiration for the latest slew of GT3 machines from the likes of Bentley, Aston Martin and McLaren but, having driven a few, I can confirm that these are recreational race cars no longer. These are cars that require not just considerable talent and skill to stay at the super-competitive sharp end of the grid, but high levels of physical fitness too. I remember talking to an exhausted Olly Jarvis, recently recovered from a Bentley Continental GT3 in the 2017 Bathurst 12 Hours, who confirmed his Audi LMP1 car was a physically far easier car to drive. “The G-force is higher in the prototype,” he said, “but it goes where you aim it. You’re fighting this every step of the way.”
That’s very good news for the top teams with seven-figure budgets and the world-class professional racing drivers they are therefore able to attract, but to the common or garden gentleman racer? Not so much.
It wasn’t always like this. Ten years ago a GT3 car like Aston Martin’s DBRS9 was quick in a straight line but not overly blessed with downforce or racing car reflexes. It felt like what it was: a road car adapted for racing purposes. Compared to its sister, the only superficially similar Le Mans class-winning DBR9, it was nowhere. But today GT3 cars are just as quick as GTE Le Mans cars, possibly quicker.
What’s less well known is that the GT4 cars that have slotted in so neatly below GT3 are as quick today as were those early GT3s a decade ago. Or at least that’s the opinion of Thomas Jäger, long-term Mercedes GT racer, former Bathurst winner and the man tasked with showing me around Mercedes-AMG’s first ever GT4.
Mercedes-AMG has been thinking about this car for a while. At least two years ago AMG boss Tobias Moers turned the tables on me mid-interview to ask if I thought he should make a GT4 coupé. I’d like to say I am therefore the reason this car exists, but the truth is the way the racing world is going, a GT4 car is as close to a no-brainer for a premium manufacturer as exists at present. They cost a fraction to develop relative to GT3 cars that are becoming ever closer to silhouette racers, go down the same production line as their road-legal sisters and sell not by the dozen, but by the hundred.
For the customer the case is equally clear: for less than half the price of a GT3 – and that’s before what for many will be prohibitive running costs – you get a factory-developed racing car, which should run trouble-free for seasons and which is eligible for championships all over the world. Yet they’re simple enough that if you wanted to keep one at home and just use it for humiliating hypercars at track days, you could.
This GT4 is based on the AMG GT R road car, currently Mercedes’ fastest car. But it is far from a street machine with some go-faster body addenda. It really is a completely different animal altogether.
On the negative side, it’s nothing like as powerful. While the GT R has 577bhp from its 4-litre twin-turbo V8 motor, the GT4 has just 503bhp. Why? Because even 503bhp is way more than it’ll be allowed once subjected to Balance of Performance assessment. As it stands, it’s still quicker than the GT R even in a straight line because it is 240kg lighter and has a better power to weight ratio.
The body uses some GT R parts, like its carbon-fibre front wings and torque tube, to which the GT4 adds a composite bonnet and aero pack. Aero is becoming increasingly important in GT4, which is why it comes with a deep front splitter, dive planes and an enormous range of adjustment for its sizeable rear wing. It carries full race suspension with two-way adjustable dampers and steel brakes because, as with GT3 cars, carbon ceramics are not allowed.
The cockpit looks like a direct copy of the GT3’s cabin – though it is actually quite different in detail – and almost unrelated to the road car. Certain other GT4 cars make little effort to optimise their interiors for racing purposes and look like road cars with additional safety equipment, but to see the lengths gone to here at least suggests a similarly thorough approach has been taken with the rest of the car.
Everything is intended to make life easier. Like the GT3, the GT4 has been designed to accommodate a driver up to two metres tall, weighing up to 130kg, which is to say almost everyone who has ever donned a race suit. It’s not particularly comfortable to wriggle in and out, but it is easy and, as important, quick.
You find yourself sitting in a carbon safety cell with your seat fixed to the rear bulkhead, centralising and stabilising the considerable mass you represent in the middle of the car. You don’t move to meet the car, it moves to meet you, both in the reach and rake of its steering column and the considerable fore and aft movement of its pedal box.
The switchgear seems to have been made by Mattel, and all the better for it because even an approximately aimed finger sitting within an inexpertly guided glove will still likely find its mark. Most controls do not require you to remove your hand from the wheel and those that do, such as the 12-position rotary dials for the ABS and traction control, are colour coded and linked to the super-clear Bosch screen where each new setting is briefly displayed as an enormous digit in front of you. I’m sure you could make a pig’s breakfast of it, but it’s hard to see how. There are even coloured bars of lights to tell you not only when the ABS has been activated, but on which axle, so you can adjust your brake bias accordingly. It seems all very simple but for amateur drivers and even professionals, anything that makes your life easier is welcome because, ultimately, it makes you both less likely to crash. Quicker, too.
The only thing I don’t like is the view out, or the lack thereof. The trailing edge of the windscreen is low, the A-pillar thick and your vision not helped by the chunky legs of the roll cage. It feels like the inside of an armoured car and, more seriously, it makes the apices of tight left-hand corners hard to see and hit. McLaren’s 570S GT4’s visibility is the London Eye by comparison.
No matter. I’m strapped in and it’s time to go. Because this is a test, there are no restrictors in place so I have all 503bhp at my disposal. In a car weighing the same as a 107bhp A-class hatchback, it should be sufficient.
A press of the ignition switch brings the 4-litre V8 to life. The most significant difference between this GT4 car and its GT3 sister is that this is the first racer to use this new motor, the GT3 still using the old AMG 6.2-litre normally aspirated V8. The first GT3 car to use the modern V8 will in fact be the Aston Vantage GT3 whose motor has been developed for race purposes not by AMG, but Prodrive.
In GT4 spec it’s already done more than 30,000km of testing and should go on and on. Its voice is not so menacingly sharp as the older atmo unit, nor do its revs rise and fall with such hair-trigger response, but it still properly thunders, which is exactly what you, or at least I, want it to do.
A pull on a paddle elicits a very mechanical clonk and, with it, something of a surprise. I thought GT4 cars needed to retain their road transmissions but I am wrong: in place of the double-clutch gearbox used in road AMG coupés, this one has its own lighter, quicker and stronger sequential race transmission made up from an AMG casing housing Hewland internals.
The last bloke who drove it managed to both stall and spin it, so despite the fact that this is meant to be an example of the most user-friendly kind of sports racer, I’m still anxious about not looking a complete twit in front of Jäger and the team. Usually the best thing in such circumstances is not to attempt to balance the clutch and throttle deftly, because – not knowing how or where the former engages – it’s likely to have the opposite effect to that intended. Just give it lots of revs and side step the clutch: it’s crude, but it works. The Pirelli slicks have been toasting away in their blankets for a while so spin only momentarily before bowling me down the Paul Ricard pitlane.
It’s a highly technical track and my visits have been too infrequent for the intricacies of its layout to be retained by my somewhat porous brain, but it is in also extremely safe so there’s nothing more than your pride to lose by pushing on a bit.
Slightly to my dismay, I don’t much like the car at first. It’s a surprise because it should be a relatively straightforward thing with which to get to grips. But I feel intimidated by the lack of visibility and steering that is too light, quite aggressive and lacking in feel. What I love is the power: in this specification it has little less than the GT3 car and with lower levels of drag it would undoubtedly draft straight past its big sister on the endless Mistral Straight even when, as today, we’re breaking it up with a chicane at half distance.
The first couple of laps are fractured, corner-by-corner affairs but as I slowly learn where to turn, unravel the mysteries of the always complicated lines and learn which kerbs can be taken as part of the track, it starts to flow. And as it does, so the GT4 comes to me.
I still don’t much like the letterbox windscreen, but once I’m going fast enough to put proper loadings into the suspension and get the car moving around a little, the rest soon starts to make sense. And there are some real surprises here. First is the downforce, which I’d not expected to be much more than vestigial: in fact it seriously expands the car’s performance envelope, never more than through the famed Signes curve at the end of the straight. No, the car doesn’t feel chemically bonded to the track in that weird way you find in prototype race cars, but there’s no question where that precision is coming from, nor the confidence it inspires. The AMG GT3 is a well-known downforce monster and at its own level its little sister seems cut from the same cloth.
What I also didn’t expect was that once I’d acclimatised I enjoyed driving it every bit as much as a GT3 car. Perhaps more. First, you don’t get quite so beaten up, or indeed made so aware of the limitations of your fitness, skill and courage. Second, it responds to more than one driving style – making a GT3 go fast is all about being as hard and late on the brakes as possible and staying there all the way through the turn-in phase, bleeding off brake pressure as downforce levels reduce, before jumping back on the gas as soon as humanly possible. With less grip/aero, the GT4 provides a middle ground, one where the car can be balanced on the throttle in the traditional way enjoyed by old-shed racers like me. Once you’ve dialled back the traction control there’s very little to fear from neutralising its inherent desire to understeer with your right boot.
Most of all, though, I appreciated how much more evenly allocated this unfettered GT4 car’s power and grip reserves are over any GT3 I’ve driven. The truth is that GT3s are as unremarkable in a straight line as they are extraordinary under brakes and through corners, but this GT4 feels well served and equally provided for in all three disciplines.
Prior exposure to other GT4 machines had suggested this formula now represents the absolute sweet spot for people who want to race a car with slicks and wings, but who enjoy the simple business of driving as much as shaving every last tenth off their lap times. A modern GT3 car has to be set up for a professional driver because that’s how it will go fastest. But that’s not how to make it the most fun to drive. And that’s the point: GT4 cars are far slower from one point to the next but if you could measure the breadth of the smile on the drivers’ face after a decent stint I think you’d find them far more evenly matched. And if driving pleasure gained per pound spent could ever be quantified, I’d expect you’d find the far more accessible GT4 cars are in a different league. Let’s just hope they don’t go the way of GT3 cars over the last 10 years, and get to stay that way.