New BMW M6 Convertible in Depth

BMW's fastest ever soft-top

By Text & Photos edited by Clinton Deacon
October 12, 2006 5:02 AM
Filed Under: BMW, German

Press Release

Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications


BMW's fastest ever soft-top, the new BMW M6 Convertible, takes centre stage at the British International Motor Show. On sale in September 2006 and powered by BMW's multi-award-winning 5.0-litre V10 engine, the new M6 Convertible brings the joy of open-topped motoring to BMW's M6 ?ber-Coupé.

With an engine that takes its inspiration from Formula One, the new BMW M6 Convertible promises owners one of the fastest open-top cars available. But the M6 Convertible is more than a one-trick pony. It is officially powered by the best engine in the world. Its V10 powerplant has been awarded the coveted International Engine of the Year title for the second successive year - a first in the history of the awards.

The new car also heralds the first time an M version of a BMW 6 Series Convertible has been built and three examples of this new car take pride of place in the BMW Group Plaza at the British International Motor Show.

Drivetrain:

Powered by a 4,999cc V10 engine developing 507hp, the M6 Convertible engine is a technical tour de force. Using BMW's innovative Bi-VANOS variable valve technology and individual throttle butterflies on each of the engine's 10 cylinders for optimum breathing, the M6 Convertible delivers true supercar performance. The 0-62mph sprint is achieved in 4.8 seconds before going on to an electronically-limited top speed of 155mph. Unchecked, the car could continue to a top speed approaching 200mph.

Managing the engine's operation is the MS S65 engine management system, the most advanced electronic control unit ever fitted to a car. Capable of up to 200 million individual calculations per second - a record for a production car - the unit, along with associated electronic components, monitors the entire operation of the engine from throttle inputs to exhaust gas management. Other innovations include engine oil pumps designed to operate despite the high g-forces generated by the M6 Convertible, a unique exhaust construction that improves engine efficiency and the extensive use of lightweight materials that save weight.

Power is fed to the rear wheels via a seven-speed Sequential Manual Gearbox (SMG) with Drivelogic - the world's first such transmission and one that has already seen service in the BMW M5 and the M6 Coupé. The SMG system's Drivelogic function offers the driver a choice of 11 different gear change options - five in auto mode and six in manual mode - each offering a different speed of gearshift. On its fastest setting, the driver of an M6 Convertible can make gear changes in just 50 milliseconds - a much faster time than could be achieved by an experienced driver using a conventional manual gear box.

Lightweight Design:

The new BMW M6 Convertible showcases many lightweight materials that reduce unsprung weight, thereby improving ride and handling while minimising consumption and emissions figures. Thermoplastic front wings and Sheet Moulding Compound, another form of hi-tech plastic, form the boot lid and spoiler, and reduce unwanted mass. The use of lightweight aluminium components throughout the car saves further weight while retaining the same levels of strength offered by heavier steel.

In comparison to a standard 6 Series Convertible, the M-variant has revised front, side and rear bodywork for enhanced aerodynamic efficiency and to help engine cooling. BMW M's signature quad exhaust pipes protrude from the restyled rear valance. The M6 Convertible also features a triple-layered hood with a middle component of polyurethane (PUR) foam for the most refined closed-roof driving. The hood has also been designed so that the roof-up profile has a near identical silhouette as the M6 Coupé.

Chassis;

Even with its soft-top configuration, the M6 Convertible offers one of the most rigid chassis available. BMW's renowned Variable M differential, used on all current BMW M cars, ensures the BMW M6 Convertible offers the driver the highest levels of traction and stability. The Variable M differential permits up to 100 per cent of drive to be fed to a single rear wheel to optimise traction. In its optimum MDynamic Mode, as a part of the Dynamic Stability Control system, it permits a greater degree of wheel slip for safe and exciting driving.

BMW's familiar double joint strut front axle is used on the M6 Convertible, while, at the rear, an integral axle with longitudinal arms with springs and dampers feature. In common with all previous BMW M developed cars, the BMW M6 Convertible is fitted with a hydraulically assisted rack and pinion steering. For ease of driving and manoeuvrability at slow speeds, the steering system is supplemented by BMW's Servotronic speed-proportional steering system.

Safety:

The BMW M6 Convertible offers the highest standards of passive safety. A-pillars made of high-strength steel and rollbars behind the rear headrests form a top-level safety cell in the event of a rollover. Active rear seat head restraints also pop-up in extreme circumstances should the Dynamic Stability Control system detect an imminent rollover to provide the optimum occupant protection. The M6 Convertible is designed with deformable body panels to absorb impact energy while high strength steel is used at key points of the chassis to prevent any intrusions into the passenger compartment.

Fitted as standard with four airbags, the driver's and front seat passenger's intelligent airbags offer two-stage deployment, depending on severity of impact. The safety belts on all four seats come with belt force limiters and the integrated restraint systems on the front seats also feature belt latch tensioners.

The M6 Convertible is also equipped with Adaptive Headlights as standard. This innovative system turns the car's headlights in relation to steering input by up to 15 degrees when cornering. As a result, the direction the car is travelling is illuminated for greater nighttime visibility. The M6 Convertible is further equipped with Brake Force Display and Head-up Display. The former illuminates additional lights at the rear during heavy braking to warn other road users, while the latter system displays speed, navigation, cruise control settings and check control messages in the driver's line of sight for safer driving.

With no spare wheel and tyre, the M6 Convertible features BMW's Tyre Puncture Warning System (TPWS) and a second generation M Mobility System (MMS). The former gives an audible and visual warning if a loss of tyre pressure is detected, while the latter provides the driver with a get-you-home method of tyre repair.

Market and history:

The M6 Convertible is unique - it is BMW's first ever M-badged high performance 6 Series Convertible and comes to the market at a time when demand for soft-top cars has never been greater. In 1993 UK car buyers bought 22,510 soft-top vehicles, while in 2005 108,618 convertibles were sold.

The UK has traditionally been the third largest worldwide market for M-cars and the second largest European market for soft-tops. The introduction of the M6 Convertible is, therefore, a logical step for BMW. The M6 Convertible promises to be one of BMW's most exclusive cars and, in its first full year, BMW UK expects to sell 150 cars.

Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications


BMW’s stunning new convertible literally lifts the lid on M6 dynamics. Lightweight technologies and innovative materials combine with the latest convertible roof design to deliver M6 Coupé performance, roof up or down.

Exterior styling

The new BMW M6 Convertible features key design characteristics seen on nearly every BMW of the last 30 years: double kidney grille; dual headlights with corona rings and Hofmeister-kink on the C-pillar. In addition, as the latest in the line of recently launched M cars, it also features dramatic front and rear styling, 19-inch M light alloy wheels and BMW M’s trademark pair of twin exhaust pipes.

The 507hp open-topped supercar’s form has been inspired by its performance capabilities. Engineers and designers worked together to ensure the efficient and rapid supply and extraction of cool air, balanced with a head-turning design that slips through the air with the minimum of drag.

Frontal impact

At the front, the low spoiler and front bumper features a large air intake to maximise the supply of cool air for optimum engine cooling and aerodynamic efficiency. From this duct, the airflow is directed through a bespoke cooling system with the radiator split in two for packaging purposes. Compared to a ‘standard’ 6 Series Convertible, the M6 variant also features additional air intakes in place of the front fog lights. These separate cooling ducts direct airflow to the cross-drilled and ventilated disc brakes. The shape of the lower side of the valance has also been designed to reduce lift forces on the front axle.

Coupé profile

From the side, the silhouette of the M6 Convertible is clearly based on the M6 Coupé. From the shoulder line down the profile is the same, while the unique fin-structure roof defines the Convertible as its own model yet one that retains a Coupé-like profile. The front wings are flared to accommodate the same 19-inch five double-spoke alloy wheels used on the BMW M6 Coupé. Weighing nearly 2kgs less than a conventional light-alloy wheel, these rims are shod with 255/40 ZR 19 tyres at the front and 285/35 ZR 19 tyres at the rear. When compared to a ‘standard’ 6 Series Convertible the side sills of the M6 Convertible have been re-sculptured to improve the car’s aerodynamic efficiency, particularly on the underside. Even the wing mirrors have been shaped to provide downforce and keep the car planted on the road.

Motorsport rear

At the rear, a diffuser ensures smooth-exiting airflow for improved downforce and enhanced aerodynamics. Such an arrangement also allows a flow of cool air over the M Variable differential while keeping drag and lift forces in check. Four chrome exhaust pipes finish the car with an emotive M ‘signature’ – a perspective of the M6 Convertible that drivers of competitor cars will see a lot of.

The subtle restyling of the car sees the M6 Convertible marginally lengthened compared to other 6 Series Convertibles. Measuring 4,871mm long, the car is 5cms longer than a BMW 650i Convertible. The height of 1,377mm and width of 1,855mm, gives the BMW M6 Convertible an elegantly long, yet purposeful, look.

Fin Structure Roof

To give the M6 Convertible its coupe-like silhouette, it retains the roof developed by the 6 Series design team. A unique soft-top roof that features two rear fin structure buttresses. With the long hood needed to cover the spacious 2+2 passenger compartment, these fins provide the soft-top with strong support while also permitting the designers to retain the classic 6 Series Coupé profile. The inherent strength of the C-pillar-positioned buttresses renders a tightening bar superfluous and also allows the rear window to remain independent of the roof. A unique function that allows increased ventilation the roof up, extra wind protection with the roof down and better visibility than a ‘normal’ sloping rear window.

For optimum noise and heat insulation, the triple layer hood of the M6 Convertible contains a middle layer consisting of polyurethane (PUR) foam. This fabric ‘sandwich’ results in nearly the same high standards of acoustics and thermal insulation as a folding hard-top or fixed-head coupé. Compared to a soft-top hood without a triple layer construction wind noise is reduced by up to 3 decibels. When stowed, the hood sits below a watertight, dust-proof Sheet Moulding Compound (SMC) cover that fits flush with the rear bodywork. SMC is a synthetic duroplastic material that is not only strong but also saves weight.

Another added benefit of a fabric hood is that it retains a very flexible packaging concept. Unlike competitor systems with folding hard-tops that use up valuable boot space, the stowage system on an M6 Convertible retains an impressive luggage capacity of 300 litres with the roof down. With the hood closed and the hood storage compartment stowed away, this increases to a class-leading 350 litres. A folding metal roof would also weigh substantially more than the M6 Convertible’s roof.

The M6 Convertible’s roof can also be opened at speed ensuring the driver isn’t left stranded in a rain shower or at the traffic lights. Once initiated the roof mechanism continues to operate at up to 20mph allowing the driver to pull away if the lights change. Should the driver exceed this speed limit a warning signal reminds the driver and the roof mechanism halts its operation until the speed drops below 20mph.

The M6 Convertible fin-structure roof is complemented by a fully independent and retractable vertical rear window that offers better visibility than the large, sloping window of other convertible cars. Using the control panel on the driver’s door, all four windows and the rear screen can be simultaneously dropped at the touch of a button. With the hood down the window operation is reversed to offer open-air motoring but without any excessive wind intrusion.

The M6 Convertible is offered with an optional wind deflector for use when driving without rear seat passengers. This can be stored in the luggage department when not in use.

Lightweight intelligent construction

The intelligent use of lightweight materials contributes to the M6 Convertible’s 50:50 weight distribution for optimal dynamic balance and on-road agility. A bodyshell of steel and lightweight aluminium combines strength and weight-saving. Aluminium alloy housings support the front axle dampers and coil springs, while the doors and bonnet are made from the lightweight metal.

The car is fitted with thermoplastic front wings, which are lighter than aluminium. Aside from the weight saving these front wings are better able to absorb minor bumps, which improves the car’s pedestrian safety rating. In total, the front structure of the car is approximately 45kgs lighter than a comparable steel structure.

The boot lid is made from SMC and incorporates a subtle spoiler. The boot lid and integral spoiler saves weight and facilitates the incorporation of the integral telephone / navigation / radio aerial.

The front and rear bumpers are manufactured from carbon-fibre reinforced plastic and manufactured at BMW’s Landshut plant, north of Munich. In the manufacturing process individual layers of carbon-fibre reinforced plastic are laminated on a core segment cast in resin. When hardened the core is removed to leave an extremely strong, but light, hollow structure.

Finally, the underbody coverings are made from Superlite, a high quality and very durable plastic – again a weight saving measure that is without compromise.

Built at BMW’s Dingolfing Plant, the largest facility within the BMW Group’s network of 23 production plants, the BMW M6 Convertible makes use of the latest car construction techniques. Special insulating glue has been developed for bonding steel and aluminium. New technologies introduced on the Dingolfing production line also allow welding robots to intelligently select either spot welding or MAG (Metal Active Gas) welding tools. Likewise, where soldering is required, robots can choose within fractions of a second whether MIG (metal inert gas) soldering or laser-soldering is more appropriate. Various sensors monitor the MAG and MIG welding and soldering processes and also determine when further spot welding or laser soldering actions are required.

Intelligent weight distribution

The battery and fuel tank of an M6 Convertible sit low in the body of the car for optimum weight distribution and a low centre of gravity. The 70-litre plastic fuel tank is located in front of the rear axle and a jet pump and pressure-controlled dual pump ensure a reliable fuel supply even under high longitudinal and lateral acceleration. The battery is located in the floor of the boot for optimum packaging and weight distribution.

Bespoke bodywork hues

Four exclusive metallic paints – Sepang Bronze, Silverstone II, Indianapolis Red and Interlagos Blue – are available on the M6 Convertible. Other colours available include Alpine White, Black Sapphire metallic, Silver-grey metallic, Monaco Blue, Stratus Grey plus various BMW Individual colour choices.

Interior

At the wheel of a BMW M6 Convertible the driver is cocooned in a sporty, yet comfortable, cockpit. The extended leather upholstery in exclusive Merino leather is available in three colour options – Black, Silverstone II and Light Sepang Bronze. This ‘standard’ leather interior finish is fitted to the centre of the instrument panel, the centre console, the handbrake lever gaiter, armrests and seats. In the rear, the side panels are also finished in Merino leather.

Full Merino trim is available for further personalisation of the interior and is offered in five colours (Indianapolis Red and Portland Natural Brown added to the standard colours). The Full Merino trim option offers further leather adorning the instrument panel, centre console, door lining and rear side panels while alcantara-anthracite roof lining is also specified.

Easy access

Being a classic 2+2 the new BMW M6 Convertible offers sufficient room in its rear bucket seats for two adults on shorter journeys or two children on cross-continent cruises. The twin, deeply contoured rear leather seats are separated by a seat cushion to offer sound lateral support. Climbing in and out of the back is made particularly easy thanks to BMW’s Easy Access system. With this system the front seats both tip and slide forward whilst the front seat belts are also integrated with the seat backrests, ensuring nothing impedes access. A Check Control message and warning sound is triggered if the backrests haven’t returned to their correct position when the car is started.

Information at the driver’s finger tips

A new design of speedometer and rev counter feature on the M6 Convertible. Round black dials incorporate white numerals and traditional M red needles while a white corona-ring surrounding the dials is permanently illuminated in common with all recent M cars.

Another M feature to safeguard against engine wear is the tachometer display featuring a yellow pre-warning and a red warning field that inform the driver of the recommended engine speed depending upon current oil temperature. As the oil temperature rises the available speed range increases allowing the driver to observe the optimum engine warm-up routine. This arrangement is reflected in the rev range display within Head-up Display (HUD) and works as a simple indicator to let the driver know when the engine is warm enough for full throttle inputs (see the Safety section).

Aural pleasure inside and out

When not listening to the soundtrack of the 5.0-litre V10 engine, customers can listen to the latest MP3 technology. A CD formatted in the MP3 format can store in the region of 160 tracks and, when used in conjunction with a six-disc CD changer, offers the possibility of a 1000+ song catalogue at the behest of the owner.

For the best in a sound quality the award-winning LOGIC 7 Professional system is standard on a BMW M6 Convertible. LOGIC 7 works by breaking sound down into seven separate waves and then reconstructing them for optimum quality. A digital 10-channel audio amplifier and sound processor combined with 11 speakers give those sat inside the fullest and clearest of sounds from any music system currently offered by a car manufacturer.

The BMW M6 Convertible can come with the capability to receive Digital Audio Broadcasts (DAB) for the optimum in radio clarity. Courtesy of a connection kit, owners can also play music from an MP3 player such as an Apple iPod via the auxiliary socket.

W has produced. It is also the most expensive ‘standard’ road car ever built by BMW.

Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications


With its origins in BMW’s recent 10-cylinder Formula One programme, the heart of the new BMW M6 Convertible offers enthusiasts one of the most advanced engines currently on sale. It has ‘the best engine in the world’ having been awarded the coveted International Engine of the Year title for the second successive year – a first in the history of the awards.

Delivering an intoxicating blend of refined power, tractability and economy, not to mention a thrilling exhaust note, the 5.0-litre V10 unit offers the performance of a supercar for use everyday. The 4,999cc engine was the first high revving V10 engine to appear in a BMW production car, making its debut in the BMW M5 in April 2005 followed by the M6 Coupé in September. Producing 507hp at 7,750rpm, but with a maximum engine speed of 8,250rpm, the new M6 Convertible provides all the performance of an M car but with the added benefit of wind-in-the-hair motoring.


New BMW V10 engine


Layout

90° V10

Capacity

4,999cc

Bore/stroke (mm)

92.0/75.2

Valves

40

Power (hp) @ rpm

507@7,750

Torque (Nm) @ rpm

520@6,100

Maximum engine speed

8,250

Specific power output (hp/litre)

101.4

Weight (kgs)

240

Compression ratio

12.0:1

Such an accomplished set of statistics are underscored by the car’s real world driveability. A peak torque figure of 520 Newton metres at 6,100rpm is important but the engine also serves up 390Nm of torque at just 1,500rpm for real world-pulling power. This figure is made all the more impressive with the knowledge that this is a naturally-aspirated powerplant without any supercharger or turbocharger to boost output.

At full power the pistons of the high-revving naturally aspirated engine cover 20 metres a second. By comparison the pistons in a modern day Formula One engine move at 25 metres per second at 18,000rpm. Only a minor difference in speed but, while the F1 engine only has to travel 500 miles or so before a complete rebuild, the M6 Convertible’s powerplant has to last a lifetime.

Cast at the BMW light alloy foundry in Landshut, the same place as the BMW’s F1 engines, the M6 Convertible powerplant is inspired by the pinnacle of motorsport. Each of the ten cylinders has its own throttle butterfly and the new V10 engine is the first series production V-engine to feature a bedplate design for the crankcase.

Brains behind the brawn

The performance of BMW’s V10 engine would not be possible without the world’s fastest engine management system (MS S65). It can perform over 200 million individual calculations per second – a record for a regular production car engine. Compared to the award-wining E46 M3 engine, an MS S65 system is eight times faster and has ten times as much memory capacity.

Made up of more than 1,000 individual components, including a 32-bit processor, the M6 Convertible’s ‘brain’ co-ordinates all engine and gearbox functions using several subservient control units. Furthermore, it is not a component that has been bought in from outside. BMW created all the hardware and software of the MS S65 in-house and this ease of integration is one of the reasons for the engine’s outstanding performance and emissions data.

When operating, the MS S65 receives over 50 input signals and calculates the optimum ignition point, ideal cylinder charge and injection quantity for each individual cylinder on each individual combustion cycle. The unit also calculates the optimum camshaft angle and the ideal position for each of the ten individually controlled throttle butterflies.

The system manages other ancillary functions:

Bi-VANOS

All BMW petrol engines have been fitted with a variant of VANOS, BMW’s variable camshaft timing system since the M52 engine appeared in the 1994 E36 3 Series and the E34 5 Series of the same year. The latest incarnation fitted to the M6 Convertible ensures the optimum charge cycle to deliver the best balance of performance and economy.

The adjustment of the camshaft timing relative to the crankshaft is variable and controlled by the MS S65 control unit. Bi-VANOS allows for an adjustment in angle of the intake camshaft by up to 66° while the outlet camshaft varies by a maximum of 37° relative to the crankshaft. These angle adjustments are made as a function of the accelerator position and engine load. In practice, this means increased performance, an improved torque curve, optimal response to driver inputs, lower fuel consumption and fewer emissions.

For example, with the accelerator depressed and the car at low speed the Bi-VANOS system increases valve overlap thereby boosting internal gas recirculation. This reduces the chance of some of the fuel not igniting in the cylinder and lowers fuel consumption. Despite being a high performance car, the M6 Convertible records 18.6mpg on the combined cycle.

A clean exhaust and sound

Although the intake system contributes significantly to the performance of the V10 M6 engine, the importance of the exhaust cannot be underestimated. Two stainless steel five-into-one, equal length, tubular manifolds carry the exhaust gases from the engine. To achieve exact diameters, the seamless pipes have been formed from the inside using hydroforming - a high water pressure forming technique using pressures up to 800 bar to create a pipe wall thickness of just 0.8mm.

This exhaust construction process saves weight and allows for optimum engine breathing. The detailed construction and layout of the exhaust system virtually eliminates back pressure. As a result of the thin-walled exhaust manifolds, the catalysts heat up and reach their optimum operating temperature more quickly, even after a cold start.

To meet European EU4 and American LEV2 standards two trimetal-coated catalytic converters are fitted in each of the two exhausts to clean the exiting gases. The BMW M6 Convertible posts CO2 emissions figure of 366g/km. The gases leave the exhaust system through four prominent tail pipes, a BMW M trademark, that give the M6 Convertible its distinctive deep throated growl.

Lightweight engine technology

It is not just the exhaust gas manifold where weight reduction has taken place. Every gram of unnecessary mass has been removed to deliver a V10 engine that weighs the same as a V8.

The V10’s two aluminium cylinder heads are produced at the BMW light alloy foundry in Landshut, alongside BMW Formula One engines. Each features integrated air ducts (important for rapid catalytic converter warm-up) and four valves per cylinder, with valves actuated by spherical tappets with hydraulic valve play compensation. The tappet diameter has been reduced to 28mm and each one weighs only 31g.

Ten individual throttle valves

Pioneered in motor sport, each of the ten cylinders has its own throttle butterfly. The highlights of such an arrangement are:

High g-force lubrication

Under hard cornering the new M6 Convertible has the potential of generating more than 1g of lateral g-force. Under extreme braking, negative acceleration of up to 1.3g can be reached. Under such extreme conditions, it is critically important that engine oil continues to lubricate the two cylinder heads and the crankcase. The engineers have therefore equipped the M6 with a quasi-dry sump system and a ‘traverse’ force regulated supply.

When lateral acceleration exceeds 0.6g oil is forced to the outer cylinder head. The traverse oil supply system, incorporating two electrically operated duo-centric pumps, collects the oil and transports it to the main oil sump. A lateral g-sensor also transmits signals to the pumps to determine the exact volume of oil required at the sump. Using two oil reservoirs – a smaller one in front of the cross member and a larger one behind – the quasi-dry sump oil system ensures that the crankcase is never short of oil regardless of the g forces.

World’s first seven-speed Sequential Manual Gearbox

BMW was the first manufacturer in the world to offer a seven-speed sequential manual gearbox with Drivelogic. The seven-speed sequential M gearbox (SMG III) has been designed specifically for the rigours of the high revving 5.0-litre V10 engine – it is capable of handling torque of up to 550Nm and engine speeds of up to 8,500rpm.

But why seven-speed? Smaller steps between each gear reduce the dips in torque and power as each higher gear is selected. The transmission, with its short overall transmission ratio, matches the torque to the power output and ultimately translates it into optimum forward thrust.

The seven-speed SMG system is a true manual gearbox but with the gear changes managed by a super-fast electronic programme. Gears can be changed using the gear lever – forward to change down, backwards to change up – or by using the paddles behind the steering wheel. The SMG system efficiently matches engine speed, even in the case of full throttle upchanges. Offering all the benefits of a manual gearbox, such as engine braking and lower fuel consumption, the SMG system means there isn’t the energy-sapping torque converter of an automatic.

How it works

The gears in an SMG system are shifted electro-hydraulically using shift-by-wire technology – a product of the aerospace industry. This latest incarnation of an SMG system has the hydraulic unit and actuators integrated into the gearbox casing. When a change is required, the control unit actuates magnetic valves controlling the system’s hydraulics.

The hydraulic oil, operating under 90 bar pressure, flows via a magnetic valve into the clutch master cylinder to open the clutch. Then, using solenoid valves, four hydraulic cylinders in the actuator are switched, affecting the gear change process by means of four rods. When down-shifting the transmission double de-clutches automatically, including a blip of the throttle so the gears mesh perfectly.

To put this technology in perspective, the new seven-speed SMG III is 20 per cent quicker than the previous SMG II system that saw service on E46 M3 models. That’s a gear change in just 50 milliseconds – much faster than a talented driver using a normal manual gearbox who would take ten times as long.

The optimum change point is identified in the M6 Convertible using the rev band in the Head-up Display. When the rev band flashes, the optimum gear change can be achieved.

Drivelogic

An essential feature of the new seven-speed SMG system is Drivelogic, which offers 11 gear change options determined by the driver with a push of a button. Each programme offers a different speed of change. The higher the programme selected the shorter the shift time. These programmes are chosen using the Drivelogic button beside the gear lever. Alternatively the MDrive Manager function (see below) can be used to select a gear change speed as a part of the one-touch MDrive button function activated by a switch on the multi-function steering wheel.

Launch control

The concept of the sequential manual gearbox has its origins in motor sport. It is not surprising, though maybe a little indulgent, that a launch control function is included. The system is honed to ensure that the rear wheels transmit the maximum power to the road without spinning excessively. In other words, it provides the optimum straight-line acceleration.

To activate launch control:

Launch control is not a function for use on public roads.

MDrive Manager for even more control

The MDrive Manager provides one car with two or more personalities - an automotive Jekyll and Hyde. Activated by the MDrive button on the steering wheel, the driver can select very different personalities for their M6 Convertible. The system can be set up in the MDrive Manager section of iDrive. From there a number of individual performance functions of the car can be pre-selected and then activated via the MDrive button.

MDrive Manager allows a comfortable day-to-day GT to metamorphosise at the touch of a button into a raw sports car. For example, the driver of an M6 Convertible could go from gentle cruising to a car set to P500 programmed for power, the SMG set at the fastest shift setting, DSC selected to MDynamic Mode, damper control on ‘Sport’ and the Head-up Display on the M mode, all at the touch of one button.

Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications


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 Coupé 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.

Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications


Irrespective of its lack of roof, owners of the new M6 Convertible can be reassured that this open-top high performance car offers some of the most advanced safety systems currently available. The benefits of traction control have been outlined previously but the M6 Convertible’s safety blanket extends to more than just this one very hi-tech trick.

Advanced crash protection

The BMW M6 Convertible offers the highest standards of passive safety. The car’s rollover safety system consists of a high-strength aluminium alloy brace that ex­tends across almost the entire width of the car to hold the rollover bars in position. In the unfortunate event of a roll over, the roll hoops pop up within a fraction of a second from a module behind the rear seat headrests and lock firmly in position. This provides protection for all four occupants even with the soft-top retracted.

Completing this rollover protection is a windscreen frame designed to withstand high loads. Formed in sections optimised through interior high-pressure moulding the A-pillars are made of high-strength steel. Tailored rolled blanks on the rear bulkhead, on the seat supports and longitudinal arms strengthen the body panels at all points where loads and forces are high.

At both the front and rear of the car ultra-strong ‘crash’ bars use their full deformation length to offer a high degree of impact energy absorption for excellent impact protection. The entire front structure has been designed to act as an energy absorbing crumple zone. The use of lightweight but strong structures around the car absorb impact energy. As an example, two V-shaped extrusion-pressed aluminium bars in the doors significantly reduce the risk and extent of intrusion in a collision from the side.

The M6 Convertible comes as standard with four airbags. An electronics network links all the driver and front passenger airbags, and side airbags in each door. Both driver and front seat passengers benefit from ‘intelligent’ front airbags, offering two-stage deployment. In a minor impact, the bag inflates less aggressively, minimising the possibility of injury. In the event of a more serious collision, the bags deploy with full force.

The safety belts on all four seats come with belt force limiters and the in­tegrated restraint systems on the front seats feature belt latch tensioners. Satellite sensors around the car cross-reference crash signals to ensure correct deployment as a fail-safe practice.

Head-up Display as standard

While a standard HUD display shows speed, navigation instructions, cruise control settings and check control messages in the driver’s line of sight for safety, the M-specific display in the M6 Convertible takes things a step further. The engine speed appears as a rising bar chart which also flashes at peak revs to act as a gearshift indicator. This technology is a direct result of BMW’s Formula 1 activities. The HUD display in the M6 Convertible allows the driver to decide, at the touch of a button, whether to have standard information or specific M information projected into his line of sight. The driver can tailor this display to their own preference. HUD can be disengaged by activating a button adjacent to the headlight control switch to the right of the steering wheel.

High Beam Assistant

Offered as a £95 optional upgrade, High Beam Assistant offers the driver of an M6 Convertible optimum headlight illumination with the minimum of fuss. With the system fitted the driver of an M6 Convertible can drive with full beam engaged. Should the sensor located in the rear mirror housing detect the lights of an oncoming car or bike, the M6 Convertible’s headlights are automatically dipped. The system is intelligent enough to perform the same operation if the rear lights of a slower car ahead are detected. High Beam Assistant is available on the BMW 5, 6 and 7 Series models.

Adaptive Headlights

Fitted as standard to the BMW M6 Convertible, Adaptive Headlights offer a considerable safety benefit, improving visibility for drivers at night. Adaptive Headlights use information provided by the speed and steering sensors within the DSC system to provide better illumination of the road ahead when cornering. With the headlamps on the ‘automatic’ setting on the light switch, electronic motors mounted within the light cluster swivel the lamp unit by up to 15 degrees increase to illumination the road ahead. Thus, the headlamps point in the direction in which the car is travelling rather than where it is pointing.

BMW Assist

BMW Assist offers a safety benefit with its auto emergency services dial-up feature and comes as standard fitment on an M6 Convertible when Professional navigation and the optional Bluetooth phone preparation have been specified. With such an arrangement, in the event of an incident, an owner can manually contact emergency services via the iDrive controller. However, should a crash be severe enough to deploy the airbags, the BMW Assist system automatically dials the emergency services giving the location of the vehicle.

LED technology and Brake Force Display

The brake lights of the BMW M6 Convertible use light emitting diode (LED) technology. Each LED is arranged in optical strips within the lamp clusters. LEDs offer more reliability than conventional bulbs and require no maintenance. However, the real safety benefit is that they respond more quickly than conventional bulbs, communicating braking sooner to cars following behind. The arrangement of LEDs is more easily distinguished than the rear lights, as they are lit in a series of four continuous light stripes, rather than individual bulbs.

The M6 Convertible is equipped with Brake Force Display which illuminates an additional series of LEDs on heavy braking. This innovative system transmits the force of braking to other road users giving advance warning to drivers of emergency braking.

Tyre Puncture Warning System

Since there is no spare wheel and tyre, the M6 Convertible is equipped with BMW’s Tyre Puncture Warning System (TPWS) and a second generation M Mobility System (MMS).

The warning system provides visual and acoustic warnings should a tyre’s pressure fall. The design of the wheel ensures that even a completely deflated tyre will not jump off the rim, so the M6 can be brought safely to a halt. The MMS has become a tried and trusted feature of M models since the M Roadster in the late 1990’s. It uses a sealant that can plug holes of up to six millimetres long thereby enabling the car to be easily driven to the nearest garage. The system can repair almost any type of puncture without the possible danger of having to change the wheel by the roadside.

Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications


Engine

Transmission & Differential

Wheels, Tyres, Steering & Suspension

Exterior Equipment

Safety & Technology



Interior Equipment


Audio & Communication

Interior Equipment

Optional equipment



x = can be fitted

M6

Retail Price (incl. VAT)

Comments


Universal Remote Control

x

£165

Replaces up to three remote control devices (e.g. garage door openers, electric gate openers).

Climate Comfort Laminated Glass

x

£285

Infra-red reflective laminate for windscreen, side and rear windows.
Adapted to green coloured side windows with reduced interior heat build up from sun.

Madeira Walnut wood trim, high gloss

x

£0.00

Interior trim strips, dash and centre console in Madeira Walnut Wood trim, high gloss.


Natural Olive Carrara wood trim

x

£0.00

Interior trim strips, dash and centre console in Carrara Wood trim, high gloss.


Piano Black trim

x

£0.00

Interior trim strips, dash and centre console in Piano Black trim.


Ski bag

x

£235

Ski bag enabling skis to be transported within the car


TV Function

x

£820

Enables reception of analogue television programmes via the 8.8-inch colour display screen when the car is at a standstill.


BMW Assist

x

Std with telephone

Telematics service including automatic and manual emergency SOS call, BMW Breakdown Service and BMW Information Plus (location based operator service).
Includes subscription to services for six months.


Bluetooth Telephone Preparation with telematics capability

x

£465

Preparation for a mobile phone with Bluetooth interface (includes limited voice control functionality).
Please note that this does NOT include a handset or optional phone cradle and these need to be purchased separately. Includes a pre-fitted SIM card for the use of BMW Assist.
Option 612 BMW Assist is automatically included when this option is specified.


BMW Online

x

£450

WAP-based vehicle browser and access to the BMW mobile internet portal.
Services include mobile office (email, personal address book) and portfolio of online content
(e.g. latest news, weather). Includes subscription to services for one year.


Full Merino Leather Upholstery

x

£5,320

Full leather covered dash, seats, door panels, and centre console.



Page 1: Short Version
Page 2: Design
Page 3: Drivetrain
Page 4: Chassis
Page 5: Safety
Page 6: Equipment
Page 7: Specifications


Technical specifications


Please see below. click here.































Body


M6 Convertible





No of doors/seats

l

2+2





Length/width/height (unladen)

mm

4,871/1,855/1,377





Wheelbase

mm

2,781





Track, front/rear

wgsdfg

mm

1,567/1,584





Turning circle

m

12.5





Tank capacity

approx. ltr

70





Cooling system including heater

l

ltr

15





Engine oil

Getriebeöl

ltr

13





Transmission fluid

ltr

2.6





Final drive fluid

ltr

1.2





Weight, unladen, to EU standard1

kg

2,005





Max load to DIN standard

kg

450





Max permissible weight to DIN

kg

2,380





Max axle load, front/rear

kg

1,120/1,290





Max trailer load2







braked (12%)/unbraked

kg

–





Max roof load/max towbar dl

kg

–





Luggage comp to DIN

ltr

300–350





Air resistance

cd x A

0.731





Power unit







Config/No of cylinders/valves Zylinder/Ventile

V/10/4





Engine management

MS S65





Capacity

cc

4,999





Bore/stroke

mm

92.0/75.2





Compression ratio

: 1

12.0:1





Fuel grade

RON

95–98





Max output

kW/hp

373/507





at

rpm

7,750





Max torque

Nm/lb-ft

520/383





at

rpm

6,100





Electrical system







Battery/installation

Ah/–

90/luggage compartment





Alternator

A/W

170/2,380





Chassis and suspension







Suspension, front

Two-joint spring strut axle with tiebar; small positive steering roll ratios,




compensation of transverse forces; reduction of brake dive


Suspension, rear


Aluminium integral axle with longitudinal arms and double track control arms,




anti-squat and anti-dive


Brakes, front

Two-piston swing-calliper compound disc brakes


Diameter

mm

374 x 36, vented and cross-drilled





Brakes, rear

Single-piston swing-calliper compound disc brakes


Diameter

mm

370 x 24, vented and cross-drilled





Driving stability systems

ABS, CBC, DSC; Variable M Differential Lock


Steering


Rack-and-pinion steering with hydraulic assistance and Servotronic


Steering ratio, overall

: 1

13.0




Transmission


SMG III





Gear ratios I

: 1

3.985





II

: 1

2.652





III

: 1

1.806





IV

: 1

1.392





V

: 1

1.159





VI

: 1

1.000







VII

: 1

0.833





R

: 1

3.985





Final drive ratio

: 1

3.620





Tyres, front/rear

255/40 ZR19/285/35 ZR19


Rims, front/rear

8.5J x 19 EH 2 IS 12 forged aluminium/9.5J x 19 EH 2 IS 17 forged aluminium


Performance







Power-to-weight ratio, DIN

kg/kW

5.2





Output per litre

kW/hp

74.6/101.5





Acceleration 0–62mph

sec

4.8





Standing-start km

sec

22.9





In 4th gear 60–75mph

sec

4.7





Top speed

mph

1553





Fuel consumption in EU cycle







Urban

mpg

12.4





Extra-urban

mpg

26.4





Composite

mpg

18.6





CO2

g/km

366





Miscellaneous







Emission standard


EU4