Motoring / Motoring News

Glen Hill
4 minute read
9 Jul 2014
8:00 pm

New BMW Ms talk the torque

Glen Hill

BMW M3 fans are faced with two major developments with the launch of the newest versions of one of the world's favourite performance brands.

The move to a six-cylinder dual turbocharged engine is probably the most eagerly awaited, as it is a serious under-the-skin change. Secondly, and more likely to feature prominently in BMW marketing campaigns than in the minds of petrolheads, is the “introduction” of the M4 Coupe, which is really the new designation for what was known and loved as the M3 Coupe.

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Fans fearing the demise of the V8 could spell a slowing in the M3’s relentless march towards ever better cars can relax.

The new six is simply awesome and really does combine the best of a high-revving naturally aspirated unit with raw turbocharged power. Kyalami racetrack provided the empirical proof – not because of the number of high-speed laps at the vehicle’s local launch, but rather by the number of tyres destroyed by the mighty M as it screeched its way around.

My contribution to the demise of the tyres was unfortunately not so much the searingly fast laps I was able to achieve, but rather the time it took to come to terms with just how much torque was available. Anything lower than third gear and the rear threatened – promised rather – to break away until the traction control stepped in to calm things down. The M TwinPower Turbo technology helps the 3-litre engine produce 317kW and 550 Nm – quickly. The launch vehicles were fitted with the optional seven-speed M double clutch transmission and it was overly tempting to flick the steering wheel activated paddles more frequently than necessary. Until the polite BMW High-Performance instructor pointed out that the car lapped quickest using only third and fourth gears thanks to the massive torque so I was destined to wrestle with the wriggling rear – and that was with the electronics helping out.

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But once a more relaxed approach was taken, the M3 proved reasonably easy to drive, given its out-and-out performance ability, owing to how long a gear could actually prove to be thanks to the broad power band.

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The standard gearbox is a six-speed manual with a robust double-plate clutch. This unit is considerably more compact than its predecessor and 12kg lighter. As a means of increasing shift comfort, the manual gearbox uses new carbon-friction linings in its synchroniser rings. Dry sump lubrication provides an efficient supply of oil to all parts of the engine. The gearbox blips the throttle on downshifts, which improves the smoothness of the transmission.

Weight is obviously a crucial factor when building a performance car and BMW have managed to remove about 80kg compared with a similarly equipped predecessor model. That might not seem like much in the context of the approximately 1 500kg kerb mass of the M4, but bear in mind that weight penalties applied in increments of 10kg can determine the difference between the front and the back of the grid in production car racing. Indeed, in so far as I could feel a difference I felt that the better car on the track was the marginally lighter M4, despite having a personal overall preference for the M3 sedan. The weight saving has been achieved by way of increased use of lightweight materials, such as carbon fibre-reinforced plastic (CFRP) and aluminium for a number of chassis and body components. Both models feature a carbon roof.

One of the primary objectives in the development of the BMW M3 Sedan and BMW M4 Coupe was to ensure the new cars offered impressive race track capability. Hence the presence of a track-specification cooling system, which ensures that the optimum temperature balance for the engine, turbochargers and transmission is maintained at all times. Despite being subjected to continuous lapping for a couple of hours, admitedly with stops for driver changes every three or four laps, the M cars showed no signs of distress. What was interesting was that the ceramic brakes fitted as an option on the M3 clearly outperformed the conventional discs fitted on the M4. I am fairly certain this difference would only become apparent under track conditions, but it is worth remembering if you intend doing the odd track day. It would be sad not to give the vehicles excellent performance characteristics.

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An indication of just how serious the BMW engineers were about the M cars’ performance can be found in their use of CFRP in the manufacture of the drive shaft.

This component feeds the engine’s torque from the gearbox to the rear differential and works under extremely heavy loads – especially in high-performance vehicles. The stiffness and low weight of the CFRP tubing allow the drive shaft to be constructed as a single-piece unit with no centre bearing. There is a weight saving of 40% over its predecessor and consequently a reduction in rotating masses.

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There are also adjustable steering response and suspension settings, which are both essential to making the Ms genuine road and track cars, along with a host of other innovations to keep drivers both safe and excited. If you want one you will have to wait a couple of months, such is the demand. But it will definitely be worth it.

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