The M3 is changing. To satisfy BMW's responsibilities as a mass car manufacturer in a shifting world, the forthcoming model employs new technologies that offend 28 years of tradition. If turbocharging and electric steering assistance aren't implemented subtly enough,
the fifth generation M3
may lose the connected, urgent character that made earlier versions so compelling.
M President Nitschke boasts of two distinct cars
That judgement will have to wait until we drive the car next year, but for now time spent with the M division's engineers during a technical briefing near Munich was enough to persuade us that change needn't be a bad thing.
"Meticulous development work has underpinned the creation of two high-performance sports cars that set new standards in terms of overall concept, precision and agility," assures Dr Friedrich Nitschke, President of BMW M GmbH. The M3 might be changing, but it seems to be doing so within the framework of values that have defined the car for almost three decades.
That naming thing
Aside from the new naming convention - the saloon remains M3; the coupe will be M4 - the most significant change, as mentioned earlier, is the introduction of turbocharging. Although turbocharged straight-six engines have become commonplace at BMW in recent years, this 3.0-litre unit is entirely new and not related to the group's existing similar powerplants.
Drivetrain man Siegel talks us through the motor
"We don't have that much to do with BMW AG," says Norbert Siegel, drivetrain project leader. "This engine is our own development."
With a pair of dinky turbos each boosting three cylinders at up to 1.3 bar, the BMW M TwinPower Turbo engine is good for 430hp at 7,500rpm. Peak torque is said to exceed 369lb ft, and will be available from below 2,000rpm, but with oversquare cylinder dimensions - 89.6mm bore and 80mm stroke - the engine "combines the virtues of a high-revving naturally aspirated unit with the strengths of turbocharger technology," according to Nitschke.
Siegel and his colleagues have pioneered a new system that keeps the turbochargers spinning at 120,000rpm even after the throttle has been released to maintain boost pressure, which ensures immediate response once the throttle is reapplied. The lightweight forged crankshaft and hollow carbon fibre propshaft further aid throttle response. The oil and fuel systems have been designed to cope with the high transverse and longitudinal acceleration that's typical of circuit driving.
Big boasts from BMW about the electric steering
A happy consequence of opting for this engine configuration is that the engineers can use BMW's existing six-cylinder engine manufacturing infrastructure, which frees up resources for other areas of the car. The electric power steering is one such beneficiary, for the engineers have been able to invest enough time and resource into the system to achieve the necessary levels of interaction, according to Albert Biermann, Vice President of Engineering, BMW M. "The previous M3 is still the benchmark for us in terms of steering feel and the target for this new model was to beat that," he says. "The new M3 and M4 have the best ePAS systems out there."
The pursuit of lightness is a recurring theme. Rather than target the weight of the outgoing E92 model, the engineers instead set their sights on the earlier E46, shooting for less than 1,500kg at the kerb - the spirit of the CSL lives on, it would seem. Carbon fibre and aluminium body panels, forged engine and suspension components, lightweight wheels and optional carbon ceramic brakes help to keep the kilos off. The optional sunroof piles 20 of those kilos back on.
Engineering head Biermann talks weight saving
"We always intended to offer a manual gearbox right from the start," says Biermann. "It wasn't even a discussion." A seven-speed Double Clutch Transmission will be optional; could its launch control function see the 0-62mph dash dip below four seconds for the first time? That might be a tall order. Biermann tells us to expect a similar performance increase as from E46 to E92, which managed 5.2 and 4.8 to 62mph respectively.
Sideways glances
Power is latterly sent to the Active M Differential, which is capable of anything between zero and 100 per cent locking, depending on the circumstances. This, says Biermann, reduces understeer and facilitates those big smoky slides that are so iconic of the M3.
The track is wider both front and rear compared to the standard versions and the suspension arms - forged rather than cast - are bespoke, but the biggest improvement is to the rear subframe. Rather than being mounted via rubber bushings, as per the series production cars and the outgoing M3, the subframe is bolted directly to the chassis. This affords a much greater degree of precision at the rear axle and with reduced side-to-side movement the rear tyres can go up by 10mm to a 275 section Michelin Pilot Super Sport.
Prosser and Priaulx share a joke
The combination of that responsive engine, active differential and solidly mounted rear subframe should make for a direct and pin sharp relationship between throttle position and rear end attitude. Indeed, that was the overriding impression of a quick passenger ride alongside factory DTM driver Andy Priaulx on a handling course. From the wrong seat the front end felt very positive and the transition to oversteer on corner exit seemed beautifully controlled. The engine didn't feel heavily turbocharged, instead spinning up towards a fizzing redline. Don't be too concerned for a lack of exhaust noise, either.
The only significant difference between M3 and M4 will be their door counts; their characters and dynamics will be indistinguishable, we're told.
In its details, the M3 is changing. In its fundamental nature, however, Biermann and his team have worked hard to ensure it stays the same. Only time will tell if it remains the exciting livewire that we want it to be, but the signs are promising. On this fleeting first encounter it feels for all the world like M GmbH doing what it does best.
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