Press Release
Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications
-
Strong lightweight chassis with BMW??????????????????????????????????????s advanced lightweight engineering
-
Renowned M Variable differential for supreme traction in all driving conditions
-
Latest traction control system offers MDynamic Mode
-
Exclusive 19???????????????????????????????? M wheel design and high performance brakes
The performance of the M6 Convertible would be wasted without a chassis capable of handling the prodigious power. The latest construction techniques serve as a solid foundation for the open-top car. Despite its lack of fixed roof the bodyshell of the BMW M6 Convertible has exceptionally high torsional rigidity, near perfect 50:50 front/rear weight distribution, a long wheelbase and wide track, lightweight aluminium suspension components at the front and rear and is, of course, rear-wheel-drive. All combine to make the M6 Convertible one of the most agile and tractable high-performance open-top cars available.
Front and rear suspension
BMW??????????????????????????????????????s familiar double-joint strut front axle arrangement is used on the M6 Convertible and it is made largely of aluminium to reduce unsprung weight. The front axle subframe reinforcement, with special thrust plate, delivers maximum lateral stiffness, agile handling yet a compliant, smooth ride. The aluminium subframe features special air intakes used by aeroplanes and racing cars to direct cooling air to the gearbox without adversely affecting under body aerodynamics.
The rear axle, which is also made almost entirely of aluminium, is a development of the integral axle of the 6 Series. It has been reinforced for the needs of the M6 Convertible??????????????????????????????????????s higher demands by fitting additional supports, links and joints to optimise the elastokinematics. For example, rigid links have replaced rubber joints to ensure even more accurate guidance and centering of the wheels.
Like the Coup?????????????????? variant, the M6 Convertible??????????????????????????????????????s differential has been substantially modified to reduce weight and convey the huge power potential to the rear wheels. Cooling fins on the aluminium differential case have enabled the engineers to reduce rear axle temperatures by up to 15????????????????????C. The final drive is connected to the seven-speed SMG gearbox via a two-piece cardan shaft featuring a Hardy disc at the front and a constant velocity joint at the rear. The drive shafts are hollow to reduce weight and lower the car??????????????????????????????????????s centre of gravity.
Variable M differential
Like all current M products the M6 Convertible comes equipped with BMW??????????????????????????????????????s Variable M differential - the variable, torque-sensing differential lock developed by M GmbH. This provides the car with the highest levels of driving stability and optimal traction, especially when driving out of bends.
Unlike a normal limited slip differential with a 25 or 50 per cent locking capability, the Variable M differential lock can, in extreme conditions, provide up to 100 per cent locking action. This means that if one of the rear wheels loses traction on a corner the M6 Convertible??????????????????????????????????????s differential will send the required amount of drive to the wheel that obtains best grip from the road.
The system works when either rear wheel threatens to lose traction. With one wheel running at a faster speed, pressure is built up in an integrated shear pump. This pressure is transferred to a multiple-disc clutch, via a piston, where drive forces are directed to the wheel with better grip. When the difference in rotational speed decreases the locking action diminishes.
Aside from its full locking capability, the unit has other advantages. On snow, gravel or ice a conventional torque-sensing differential does not offer enough flexibility. The Variable M differential provides a substantial advantage when the driven wheels are subject to greatly varying coefficients of friction.
MDynamic Mode
BMW??????????????????????????????????????s Dynamic Stability Control (DSC) traction control system provides all BMW drivers with a safety net should the physical limits of grip be exceeded. In this situation engine output is retarded or brakes applied to inside wheels if traction is being lost, ensuring that the car will be brought back under control.
The DSC system on the BMW M6 Convertible takes things a stage further, offering MDynamic Mode (MDM). MDM allows for even greater degrees of wheel slip. Engaged via the M button on the steering wheel, MDM does not activate the full harnessing affects of DSC until the absolute limits of adhesion have been reached.
The driver is informed of MDynamic Mode by the illumination of a light on the driver??????????????????????????????????????s instrument cluster marked ?????????????????????????????????MDM??????????????????????????????????????.
Steering
The power-assisted steering in the new M6 Convertible is controlled by M Servotronic mapping. This assistance is both road- and engine-speed related, thereby resolving the balance between the need for light steering at parking speeds and more ?????????????????????????????????feel?????????????????????????????????????? at speed.
The M6 Convertible offers two different M Servotronic settings that are directly related to the EDC (Electronic Damper Control) mode. In the sporty EDC mode, the steering is very direct giving the driver an immediate, precise response. The comfort mode has a higher level of assistance for an easier, more comfortable steering reaction.
Adaptive dampers
The M6 Convertible comes with an Electronic Damper Control (EDC) system that permits the driver to tailor the suspension set up. Three settings are available ??????????????????????????????????????? Comfort, Normal and Sport. The default setting of the car at start up is Comfort, but by simply pressing a button next to the gear lever changes can be made. Alternatively changes can be made alongside other chassis characteristics using the MDrive Manager function via iDrive and the subsequent activation of the MDrive button.
EDC is a continuous and infinitely variable electronic damper control. In ?????????????????????????????????Comfort?????????????????????????????????????? mode EDC produces lower damping forces in favour of greater ride comfort. In ?????????????????????????????????Normal?????????????????????????????????????? mode the damping is automatically adjusted to achieve the optimum balance between ?????????????????????????????????Comfort?????????????????????????????????????? and ?????????????????????????????????Sport??????????????????????????????????????. In ?????????????????????????????????Sport?????????????????????????????????????? mode the damping is firmer and employs higher damping forces for a more focussed drive.
Brakes
The driver of an M6 Convertible doesn??????????????????????????????????????t so much as brake but drop anchor when trying to stop the car. Drilled, compound brake discs are standard equipment all round. At the front the discs measure 374mm x 36mm while at the rear 370mm x 24mm rotors are fitted.
Lightweight, aluminium twin-piston sliding callipers at the front (single piston at the rear) substantially reduce unsprung weight and make a further contribution towards agility, safety and motoring comfort. Whether in wet or dry conditions, the M6 Convertible provides powerful and dependable braking properties. When the brakes are applied at 62mph the M6 Convertible is brought to a halt in less than 36 metres. From 124mph the braking distance is less than 140 metres.
The brakes feature an on-board diagnostic system for pad wear. A sensor measures wear at specific points and transmits the values to the DSC system. The system then evaluates driving style and pad condition to determine how many miles to go before the pads need changing. The information is used by the Condition-Based Servicing module to determine adequate service intervals and to inform the driver in plenty of time before a trip to the dealer is required.
