Other features of the new SMG gearbox include:
- Gearchange lights and engine revolutions graphic in the Head-up Display (HUD).
- SMG includes a launch control system that gives perfect F1-style starts from zero to maximum speed. (Programme six in S mode)
- Hill start assistant prevents roll back when stopping on a gradient after releasing the brake.
- Hill recognition allows SMG to change gear points on gradients eg holding lower gears on downhill stretches and vice versa.
Agility and poise
An outstanding drivetrain cries out for a chassis that can exploit its potential. To harness 507hp effectively M engineers were presented with a considerable challenge.
They did, of course, already have a head start. The chassis of the ‘normal’ 6 Series Coupé was engineered to be the most competent in its segment. The high torsional rigidity of the bodyshell, well-balanced 50/50 weight distribution, long wheelbase, wide track, aluminium suspension and, of course, rear wheel drive all coalesce into a fine springboard.
Starting at this high level the engineers made a number of detailed changes to meet the extra demands made by the M6’s potential. They stiffened the front subframe and changed the bearings at the front while at the rear additional supports, links and joints ensure greater precision for poised handling. The suspension bushes have also been tuned with high performance in mind. The final drive casing is made of aluminium and finned to reduce weight and improve cooling. Lightweight but stiff tubular drive shafts keep moving masses low.
M Servotronic power steering is both road- and engine-speed related which resolves the dilemma of the need for lighter steering at parking speeds and firmer, ‘heavier’ steering to provide driver feedback at speed.
The M6’s Servotronic mapping offers two alternatives to the standard default setting and both relate to the prevailing Electronic Damper Control (EDC) mode. In the sporty EDC mode steering is more direct giving the driver an immediate, precise response while in Comfort EDC mode a higher ratio gives an easier, more comfortable steering reaction.
Electronic Damper Control (EDC)
EDC provides continuous and infinitely variable shock absorber control. In normal mode the damping is adjusted to achieve the optimum balance for normal conditions while ‘Sport’ and ‘Comfort’ provide firmer and softer reactions respectively.
Variable M Differential Lock
Like the M3 and the new M5, the M6 has a unique and variable, torque-sensing differential developed by BMW M GmbH. Unlike a normal limited slip differential the M differential lock can provide between zero and 100 per cent of the drive forces to either driven wheel. This ensures maximum stability and optimum traction.
Dynamic Stability Control (DSC) with MDynamic mode
A new generation of DSC was developed exclusively for 2005’s M cars and can be programmed to act in one of three stages. The first corresponds to a standard DSC system found on all BMWs, while the second, MDynamic mode is unique to the M5 and M6 and allows the driver to really ‘push the envelope’ of the M6’s performance capabilities.
MDynamic mode is a development of BMW’s Dynamic Traction Control system. DSC set at this stage will not intervene to save things until the last possible moment. Therefore the M6 can reach amazing slip angles and still recover. The desired programme is initially selected using the MDrive Manager programme but is then subsequently activated by simply pressing the MDrive button on the steering wheel.