INSIGHT. M4 GT3 – The future of BMW Motorsport

News | November 17, 2021

At this weekend’s Hankook 24H SEBRING, the BMW M4 GT3 will face arguably its biggest test to to-date with its first 24-hour endurance event. But as we learn from head of BMW M Motorsport Mike Krack, the brand’s new racing flagship is more than up to the task.

Back in September, a new era for BMW Motorsport began as the BMW M4 GT3 competed in its first-ever race. The debut, at round seven of the newly rebranded Nürburgring Endurance Series (formerly the VLN), not only sent the M6 GT3 officially into retirement after five seasons, but simultaneously marked the “finishing straight” of an expansive test program for BMW Motorsport’s new flagship. A project that, since work began with computer simulations in 2019, incorporated more than 14,000 testing kilometres and over 70 hours at various racetracks across Europe, including Miramas in France, Almería and Monteblanco in southern Spain, and, unsurprisingly, Germany’s Nürburgring. 


As of this weekend, you can add the Sebring International Raceway to that list too, with the BMW M4 GT3 gearing up for its first-ever 24-hour endurance event under the factory banner.


While BMW will, understandably, be looking to downplay the car’s chances at the event – the Hankook 24H SEBRING is effectively still a test event for the new M4 – expectations will be high, nonetheless. The outgoing M6 GT3 was no stranger to 24-hour race wins after all, having taken the honours at the Nürburgring, in-class at Daytona, and at Spa-Francorchamps (twice).  On top of that, back in June 2020 and shortly after Augusto Farfus rolled out a heavily-camouflaged prototype at the BMW Group’s Dingolfing facility, the Bavarian brand’s Motorsport Director Jens Marquardt gave the new GT3 few places to hide, stating that the M4 had “everything it needs to continue the successful history of BMW Motorsport as a new GT icon.”

It's difficult to argue with that. Developed over two years and in tandem with the BMW Competition roadcar, itself a more dynamic version of the hardly lethargic BMW M4, the GT3 features a heavily developed drivetrain, stronger brakes, upgraded suspension, an even more rigid chassis, and revised aerodynamics, all of which started with CFD computer simulations in 2019. The M4 also ushers in… the new ‘face’ of BMW.


…let’s just get this over with…


“The double kidney is the central brand recognition sign,” explains Mike Krack, head of BMW M Motorsport. “It is an iconic graphic whose shape has varied over decades. With the new BMW 4 Series, it is again vertical and very expressive, and thus deliberately polarizing.”


‘Deliberately polarizing’. That’s putting it mildly. 


When both the roadcar and the GT3 were unveiled in camou livery last summer, social media parted quicker than the Red Sea as BMW enthusiasts applauded the “bold new look” while detractors played fast and loose with the “buck tooth” settings on their photoshop. Of course, for the brand that had already ‘been there, done that’ with Chris Bangle’s controversial re-design in the early 2000s (a look that, in fairness, many now consider ahead of its time), what lay behind the M4’s new face was far more significant.  

In contrast to the 4.4-litre M TwinPower Turbo V8 powering the outgoing M6 GT3, the new M4, like the first generation roadcar, is kitted out with a turbocharged straight-six, albeit one specifically “designed from the outset for use at the racetrack”. There’s been a notable weight drop for example, courtesy of a new lightweight crank and a 3D-printed cylinder core, the latter providing a more flexible method of production. And that’s just for starters…


“The M4 GT3’s engine is 40kg lighter than the V8 engine of the M6 GT3,” Mike continues. “Modifications compared to the ‘S58’ engine in the BMW M4 Competition are in the following areas: installation angle, dry sump, engine-mounted oil tank with integrated oil/water exchanger, intake system with charge cycle split and two throttle valves, exhaust system with charge cycle split, engine mount and attachment adapted to GT3, and rear torsional vibration dampers.


“All of this results in better weight distribution and ‘drivability’, so tyre wear is also a lot better with the M4 GT3 compared to the M6 GT3.”

The comparisons with the M6 don’t end there. Balance of performance regulations will inevitably play their hand, but the M4 GT3’s 2,993cc straight-six, with a full head of steam, produces “up to 590hp” at higher revs compared with “up to 580hp” from the M6 GT3’s 4,399cc V8. As a result, the M4’s 197hp/litre specific output similarly hurdles over the M6’s 132hp/litre. And yes, those elongated and frameless nostrils do put function before form by sending more airflow to the engine bay than before. 


The M6’s Ricardo six-speed gearbox meanwhile been replaced with an Xtrac example (the Competition roadcar features an eight-speed automatic as standard), which sends power to all four wheels. It’s also been mated with a new, lower wearing electro-hydraulic clutch. Even the M4 GT3’s €415,000 price tag limbos under that of the M6 to the tune of €4,000.


Stonking power was not the primary goal behind the M4 project, however. Bracing upon bracing at the front, middle and rear, plus deft use of aluminium in the subframes, mean both the longitudinal and torsional stiffness of the M4’s body are stronger than the previous generation. Oddly, sitting as it does on a 2,917mm wheelbase, the new M4 GT3 is also longer (5,020mm vs 4,975mm) and only marginally narrower (2,040mm vs 2,046mm) than the meme-inspiring M6. Theoretically then, the wider track, plus new adaptive suspension, mean handling and driveability should be on-point. 

That’s certainly how factory test driver Jens Klingmann feels anyway: on the prototype’s first run around the Nürburgring back in April, the 2007 Formula BMW champion stated that “the BMW M4 GT3 has retained the strengths of its predecessor on the Nordschleife, while eradicating its weaknesses.” That’s pretty impressive when you consider most of the M4’s development was done during a global pandemic!


“Compared to the M6 GT3 there are significant improvements to the M4 GT3, especially regarding drivability, cost efficiency and operation. The M6 GT3 was a bit harder to drive for gentleman drivers and running costs were higher compared to the M4 GT3. 


“Aside from the basic car shape, which is the baseline for its aerodynamic performance, the other main aerodynamic elements are the front splitter, the flat underfloor and the rear diffusor.” – You probably also noted the Porsche 992-esque ‘swan neck’-mounted rear wing. – “We’ve also paid attention to the aerodynamic performance of smaller elements like the rear view mirrors, the small turning vanes on the front splitter underside, and the louvres on top of the front fenders.


“Given the difficult conditions of the past few months, it is quite remarkable that we have managed to implement our development program as planned, whilst simultaneously complying with the BMW Group’s strict safety and hygiene regulations throughout the COVID-19 pandemic. We even managed to stick to the dates originally envisaged!”

Ironically though, the tour de force of the new BMW M4 GT3 is probably on the inside. In an unorthodox move, BMW Motorsport has developed a bespoke steering wheel with Fanatec, a leading brand in the development and construction of sim racing hardware. One that, in a world first, can transition from the simulator to the ‘in the metal’ racecar completely unaltered. It just might be the ace up the racesuit sleeve of every young and/or ‘gentlemen’ racer looking to hone their skills across both disciplines.


“The M4 GT3 steering wheel is very special, unique and ground-breaking in many ways. Of course, it is amazing for professional and amateur sim racers to be able to use the exact same steering wheel in their simulators that BMW works drivers use at races like the Nürburgring 24 Hours. But the steering wheel can offer much more. Drivers can also adjust and activate essential settings in race mode, like traction control, radio, ABS, engine mapping, windscreen wipers, drink system, etc.


“Elsewhere the cockpit has a BMW M safety seat in accordance with the latest FIA standards, and a new air conditioning concept with cockpit air circulation for significantly greater efficiency. BMW has worked hard to make sure the air conditioning system is easy to maintain and twice as powerful as that in the BMW M6 GT3. The steering wheel, pedals and centre console can all be adjusted. There’s dimmable illumination of controls, display and switch arrangement for best possible ergonomics and maximum comfort. That’s particularly important in endurance races. Driver comfort altogether has just been vastly improved.”

The question now of course is how BMW’s newboy will handle its first 24-hour endurance race. As of 2022 after all, this is the model that will take on Porsche’s 911 GT3 R, Audi’s R8, Ferrari’s 488, Lamborghini’s Huracán and McLaren’s 720S, among many others, in, what is quickly becoming, a resurgent GT3 field worldwide. Sebring is unlikely to yield definitive answers of course. But across 24 hours, there will be nowhere for BMW Motorsport’s “new GT icon” or its deliberately polarizing kidney grilles to hide…


“We are deeply convinced that GT3 racing will be a big part of the future of combustion engine racing. Just look at the DTM’s new GT3 class, and GTD Pro in IMSA from next season. GT3 offers the best opportunity to take part in some of the biggest races and racing series in the word, without having to spend huge budgets. We’re confident the BMW M4 GT3 will play a significant role in that.”

-       Words – James Gent

-       Images – Petr Frýba

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