Expert dialogue with Maximilian Ahme via M-Power.

Maximilian Ahme will answer the questions of MPW members. He is responsible for the technology of the entire vehicle with the exception of the electronics.

When did work begin on the development of the BMW M5 and how many kilometres were covered during testing?

Two to three years must be allowed for testing the development of a BMW M. In some cases predecessor vehicles are used in the first phase, enabling initial engine tests to be carried out, for example. However, this is just a short phase. The fine tuning then involves the latest models. The development departments for engine, electronics, chassis, etc. each have their own test vehicles to enable them to put the latest technology to the test. Approximately 2 million kilometres were covered throughout the world by the new BMW M5 in this way. How does the engine of the BMW M5 differ from that of the BMW X5 M/X6 M?

The engine of the BMW M5 has been almost completely redesigned. In essence, the only feature it has in common with the engine of the X5/6 M is the bank angle (90 degrees) and the cylinder spacing. The specification sheet also indicated a higher maximum rotational speed of 7,200 rpm.

A lot of new features have been added in order to cater for the demands for low fuel consumption and good response: starting from the continuous regulation of the variable valve timing (VALVETRONIC) by means of the optimised cross-bank manifold to the dethrottling on the intake and output side, where we use larger charge-air coolers and turbochargers with more air throughput according to the M-TwinScroll concept. This required a new cylinder head with new valve drive mechanism and high precision injection. VALVETRONIC is combined with direct injection with an eight-cylinder drive – BMW M has done some pioneering work here. This measure also saves fuel. The oil circulation system has been optimised: a wet sump with an additional oil pump, which has already proven itself in the previous engine. Engine and transmission control are also new. The overall package guarantees a responsiveness familiar from earlier M models with no sign of the so-called “turbo lag”.

Why wasn’t the automatic torque converter transmission adapted from the BMW X5 M/X6 M?

The new V8 engine in the M5 provides maximum performance between 5,750 and 7,000 rpm. In conjunction with the specially tailored M DKG dual-clutch transmission, we use the maximum engine speed of 7,200 rpm as we move up the gears in sporty driving style to ensure that we start off in each new gear with maximum output. This is precisely what we wanted to achieve by increasing the engine speed range. An automatic torque converter is not designed for the required speeds and could not be used for this reason. In addition, only the DKG dual-clutch transmission allows you to change gears without interrupting traction. This is very important for good acceleration times… There are no disadvantages in terms of fuel consumption as this is more dependent on overall transmission ratio rather than the number of gears. How do you get a turbocharged engine in a car to reach speeds of up to 7.200 rpm? Until recently this seemed impossible.

This isn’t so much a question of the speed of the engine or turbo-charger, after all we have already had speeds of up to approx. 14,000 rpm with the BMW Formula 1 engine. The characteristic zone of the charger in terms of pressure and volume has to be adjusted to the gas throughput of the engine. This in turn depends on the displacement, speed and required output characteristics. The principle is as follows: small chargers are good for fast responsiveness and high torque at low engine speeds, while large chargers are good for high maximum output. I think we have achieved the best possible compromise here with the new M5 in terms of responsiveness and power characteristics.

How does the cooling system work with 10 coolers?

With an output of 412kW / 560 HP, the new BMW M5 has power to spare and offers excellent driving performance. However, this enormous output creates the same level of combustion heat in all high-performance engines. In the case of the Formula 1 engine, the coolers are housed in an exposed position in the side boxes – a different solution needs to be found in the case of a sports limousine. For the new BMW M5 we have developed a tailor-made cooling package that covers all our requirements to perfection. A total of 10 coolers ensure that the temperature is kept just right, while also supporting the spontaneous response of the V8 engine.

The principle of direct or indirect charged air cooling applied to turbocharged engines. Air-to-air heat exchangers are used in the case of direct turbocharged cooling, which would have required much longer paths to the front of the car for the charged air with a lot of dead volume in our case. That’s why we use an air-water heat exchanger placed between the compressor and the intake manifold for every turbo charger. The heat generated while compressing the air is fed to three water-air coolers in the front of the car by means of the medium of water. The charge air thus takes the shortest path with a large diameter from the compressor via the charge air cooler directly to the intake channel. This improves the engine response. We have an air-water cooler and a total of three water-air heat exchangers for each cylinder bank: one radiator in the wheel arch to the left and right and one in front of the main heat exchanger. This means that a total of five coolers with their own reservoir and 2 electrically powered water pumps are used to cool the charge air.

In addition, there is the radiator for the main cooling circuit (high temperature circuit), familiar from every car. In the classic configuration, additional coolers are provided for the engine and gearbox oil and the steering hydraulics. Finally there is the condenser for the air-conditioning system. That makes ten coolers in all. The rear axle differential has an aluminium oil tray with cooling fins so that a separate radiator is not required there. A smaller offset in the differential reduces friction and therefore the build-up of heat. Less friction means less fuel consumption here too.

What role is played by the Efficient Dynamics measures in reducing ECE normal consumption by about 30%?

Such a reduction in consumption to 9.9 l/100 km in the ECE cycle is achieved through BMW EfficientDynamics measures and an improvement in efficiency. We have already explained how this works with the rear axle differential. In the case of the engine, the variable valve control and dual variable valve timing and the high torque at low engine speed make a significant contribution. On top of this comes the automatic engine start/stop, varioserve power steering pump, volume-regulated engine oil pump, roll-resistance-optimised tyres and brake energy recovery in order to charge the battery when coasting. The entire package helps in achieving consumption targets without compromising on driving pleasure. Another benefit: when consumption is taken together with the larger tank, the vehicle’s range is significantly increased.

Why is an all-wheel drive still not an option with the BMW M5?

In view of the performance and torque of the BMW M5, this might be considered an option. However, we believe any advantage is outweighed by the disadvantages of the all-wheel drive. More weight due to four driven wheels means higher fuel consumption and a shift in the axial load in the direction of the front axle. However, we are particularly concerned with a balanced distribution of weight for the driving performance typical of the M. We also had to position the engine higher, which would have led to a higher centre of gravity.

Why wasn’t the fuel tank volume increased to even more, e.g. to 90 litres?

We made the best possible use of the space under the rear seats. That’s why a steel tank is used instead of a plastic one. Steel allowed us to achieve the same rigidity with thinner walls and enabled us to increase the tank volume from 70 to 80 litres. We genuinely fought for every millimetre. After all, safety clearances also have to be met.

The press folder reads “innovative active M differential for optimising the transfer of power to the back wheels”. What is the innovation in the BMW M5?

The variable differential lock in the previous model is controlled by the speed differential between the drive wheels. In other words, this is a passive system in which the lock is activated by different wheel speeds. This is now achieved proactively by means of an electric motor with downstream transmission and ball ramp. We use a similar package of discs which is pre-stressed by means of the electric motor. The driver’s preferences are also taken into account, i.e. when the driver accelerates, the system starts to lock, even in response to fast-changing frictional conditions, e.g. on a “patchwork” of snow and asphalt. The system also operates when the car is coasting – the lock is activated when the wheel sensors detect the relevant values. This makes for greater driving stability. A passive system does not react in this case. While a passive system always operates with pre-stress, the active lock can be completely unlocked. One advantage of the reduced friction is the reduction in fuel consumption. When the M differential lock is active, we can still start off on mountain slopes even with a 25 percent incline and extremely variable frictional values (ice/asphalt). When you are on the slope, you find it hard to believe that you will be able to start, but is really does work. This is a better alternative than walking on the ice…

What is the role played by the tyres in determining the complex chassis regulation systems?

A large part of the car’s driving performance is determined by the tyres. The force transferred when the car is in a bend, or accelerating or braking passes through the tyres. The same is true of the response from the road. Chassis adjustment and steering are at least equally important. It takes tyres that are precisely tailored to the chassis to achieve the superior driving performance associated with the BMW M5. We develop our cars in close cooperation with the tyre manufacturers and for a particular tyre type. Tyres need to meet very stringent criteria, which is why it is not easy for tyre manufacturers to receive approval from us. I would therefore advise you only to use the tyres we approve.

Why was it decided to have two M Drive buttons?

Just one button only allows two adjustment options: the basic setup when starting and the personalised M Drive button configuration. This comprises the setting options for the engine and accelerator pedal characteristic curve, DSC, EDC, M DKG, Servotronic and Head-Up Display. The M5 is now always started in Efficient and Comfort mode, in other words the best setting for fuel consumption and comfort. One M button is now permanently set to Cruise mode, i.e. an automatic setting still applies, although the engine speeds increases and combustion has not yet reached its highest point in the chassis, so that I am still travelling at a reasonable speed. The second alternative is the sporty variant, where I shift gears myself (via the steering wheel paddles or using the gear stick), activating higher damper forces, giving me greater steering forces and making the engine respond even more aggressively. Many customers will probably be happy enough with these three setups. Everybody else will find it easy to adjust the assignment of the two M keys to their needs on the basis of the permanent basic setup.

How much more output is available in Efficient mode? How do the three modes differ?

There is no difference in terms of output, however the ratio of accelerator pedal position to power development varies. In “Efficient” the characteristic curve is flatter for a more gentle use of output, while is it much steeper in “Sport plus” for a very spontaneous and direct development of performance. Thus, unlike its predecessor, the BMW M5 always has full power available as and when you need it.

How has the chassis been altered in comparison with the BMW Series 5?

The front axle has a more rigid connection to the bodywork. In addition, the track has been widened, when meant that we had to move the wings further apart. We have broadened the support base of the front axle bracket, also reinforcing it with a shear panel – a metal plate screwed onto the front axle bracket at calculated points. This means that the forces are applied to the bodywork over a large area. This increases torsional rigidity, so that the body of the car is subject to even less distortion. In terms of kinematics, the rear axle follows the excellent principle applies in the predecessor model. However, the rear axle support is rigidly connected to the body, i.e. there are no rubber bearings. This results in greater driving precision and good responsiveness. A traction field is used following the same principle as on the front axle. On the rear axle we apply forces that affect the chassis, side skirts and transmission tunnel via a package of struts. In conjunction with the hydraulic rack-and-pinion steering with variable ratio, the drive receives very precise feedback regarding the road and the car’s reaction.

How high is the maximum lateral acceleration?

Depending on the road surface and ambient conditions, it can reach levels of up to 1.2 g with our standard tyres. This is not a constant value. Irregularities and unevenness on the road mean that short peaks of up to 1.3 g can be achieved, or perhaps even a little more on the Nürburgring circuit, for example, when the tracking force is briefly increased through compression. Thus, the 1.2 g simply relates to a so-called “standard curve”.

Which detailed solutions posed the greatest challenges?

The whole is more than sum of the parts. In view of the enormous performance, the coordination of the regulating systems is a particular challenge. In the final analysis, our customers and their families should be able to discover the versatility of the BMW M5 for themselves, whatever the weather. On the other hand, the BMW M5 should also shine on the race track. Reading the press reports, I’d say we have obviously succeeded.

Subscribe | Download (10 MB MP3)

After a long day of interviews at the North American International Auto Show Todd and Matt caught up with BMWNA’s M Boss Matthew Russell with an impromptu interview that covered a range of topics. First up we talk 3 Series and the fact that the NAIAS this year is all about 3er. But then we quickly move onto the M5 and why Mr. Russell loves the X5M but thinks the M5 is hands-down the best car in the world.

Then things move onto the 1M and Todd asked the big question; will we ever see a 1M again? Mr. Russell clearly admits that M took notice of the excitement around the 1M but no promises have or will be made any time soon.

What about the US Alpina range that Russell also heads? Will we see something more than a B7 that’s currently in the US market? Russell would like to see some new offerings – especially something like the diesel powered D3. There’s also clearly more that can be done on the 5 and 6 series platform and Russell doesn’t want to rule anything there either. But at this time there’s nothing to confirm.

It’s a quick show but one we’re sure you’ll enjoy.

It officially official now. Though confirmed to us by sources and at the international press launch BMWNA has taken the wraps off the 6 speed manual for the new ///M5.

Official Release: Detroit, MI –9:00am EST January 9, 2012…

On the occasion of the North American International Auto Show, BMWNA officially confirmed today that it will offer a 6-speed manual transmission on the North American version of the upcoming 2013 BMW M5. The 6-speed manual will be available from the start of production this summer and will be offered as a no-cost alternative to the standard 7-speed M-Double Clutch Transmission (M-DCT). The manual gearbox was a popular choice for U.S. customers of the previous generation M5 and continues to be a unique offer in the segment.

The 2013 M5 will arrive at US BMW Centers in late summer 2012. Pricing, options and specifications will be released closer to the on-sale date.

The heart and soul of BimmerFile (as the case with MotoringFile) are the reviews. And it’s not just the new cars we’re after but the classics. This year we were lucky to review a couple instant classics and one that is unarguably the real thing. Our reviews of the 1 Series M Coupe and the F10 M5 surely fall under the former. They each represent a step towards the future for BMW M while keeping an eye on the past. But it was a 39 year old coupe on a storied road that completely stole our heart.

2011 BMW 1 series M Coupe: Road/Track 1st Drive

In the 1M BMW has created something entirely new on paper that comes straight from it’s heritage. Whether you look at the 2002 Turbo or the E30 M3 there’s some much classic blueprint there from previous great cars that it would have been shocking if the 1M didn’t blow us away. But no trouble there because it did (and pretty much every one else who drove it.

2013 BMW M5: 1st Drive

Then there’s the M5. A car that has a tremendous reputation and history to live up to. It’s a car that defined a genre while not being afraid to reinvent itself in each successive model. The F10 follows that trend by reducing the cylinder found back to E39 levels and adding two turbos. It’s larger, heavier and faster than anything that has come before it. But it’s also more efficient than the last M5 and introduces a number of new technologies to the range. But that’s not why we loved it. We loved it because the way it drove on the road and on the track.

1972 3.0 CSL: The Ultimate Drive

While there were a number of really good cars released by BMW in 2011 (the 6 Series Coupe should be counted among those) it was a 39 year old car that made perhaps the biggest lasting impression on me. The 3.0 CSL was paired with one of the most noted roads in North American – Carmel Valley Rd just outside of Monterey. In all it made for an afternoon I won’t soon forget and one of my favorite reviews I’ve ever written.

German publication Autobild took the entire current M range (including the ultra rare M3 CRT) to the Sachsenring. The winner? Perhaps unsurprisingly it was the über M3, the new CRT. But what of the standard production models? The F10 M5 bested the lot with a time of 1:38.90. Not bad for a heavy-weight. But it was the race for second that caught out attention.

As you can see below the 1M bested the DCT and Competition Package equipped M3 by .34 of a second.

• BMW M3 CRT / 1:38.87
• BMW F10 M5 / 1:38.90
• BMW 1M Coupe / 1:40.18
• BMW M3 Coupe DCT / 1:40.52
• BMW M3 Sedan DCT / 1:40.60
• BMW M3 Convertible DCT / 1:42.63
• BMW X6 M / 1:43.67
• BMW X5 M / 1:43.72
• BMW E60 M5 / 1:43.77

Source: Autobild / Via: F10post

Is it pointless? Sure it is but it is always fun to watch tires rapidly lose their longevity. As we’ve told you, the M5 will drift with the best of them. Autocar UK’s, Will it Drift? host Steve Sutcliffe does his best to show just how much drifting can be done.

Subscribe | Download (45 MB MP3)

After a very long break we’re back with another big show. First up we recap the last two months of BMW news starting of course with the 6er Gran Coupe and then quickly moving onto the F30 and next generation M3. We round out the news with some thought on DTM and the future of BMW’s racing programs. But this show is all about our personal highs and lows of the year with Michael and I dishing a few surprises.

Here’s the full list of news recapped (after the break).

• 6 series Gran Coupe
• M6 Gran Coupe
• F30 and BMW of North America’s option snafu
• F80 M3 updates (V6 or not?)
• DTM and the future of the M3 in racing

You want the facts. You’ve got ‘em in 90 seconds from our friend, M Brand Manager Matt Russell.

We are just a few days away from Christmas, the anticipation is nearing as the final decorations are put up and holiday cards are opened. If you have been procrastinating and haven’t sent out cards, or prefer last minute digital cards, BMW Switzerland has created something for BMW enthusiasts, M enthusiasts to be more exact.

The card above is what happens when an M5 gets involved in creating greetings of great joy. The full video of the experience an artist had attempting to create a stereotypical Christmas card while in the passenger seat of an M5 is after the break. It’s an amusing idea and goes to show how great the M5 truly is.

560 HP CHRISTMAS GREETINGS.

Thick fog covers the Anneau du Rhin circuit. The prominent sound of 560 hp abruptly slices through the peace and quiet. The new BMW M5 breaks through the mist.

In the driver’s seat: a BMW precision driver. In the passenger seat: an illustrator creating a Christmas card design at full speed.

At breathtaking speed, the sportsman races through narrow curves, while the illustrator tries to hold his pen steady – in vain. Thus the fastest Christmas card in the world is created in the new BMW M5.

You are holding the result in your hands: unique, created at up to 250 km/h, and documented for you on film below or at www.fastestchristmascard.ch

With this card full of sheer driving pleasure, we wish you a peaceful festive season and a dynamic start to the year 2012.

What happens with EVO gets their hands on a F10 M5, Porsche Panamera S, Mercedes E63 AMG and a Jaguar XRF? First a full on comparison test – coming in the next edition of EVO. Then the inevitable; a 0-1000 meter drag-race.

While we are always expounding the virtues of how each M car does in the corners, there’s something primal and just plain awesome in seeing one go down the quarter mile. And here we have the ultimate test of group drag-race of fast Q-cars. See how it goes down after the break.

So why no Panamera Turbo? Price. The S is the one that directly competes against the M5 in price and market position.

We cannot pass up a chance to watch the M5 go sideways around a corner. Nor can we stop looking at photos of the F10M. Luckily BMW UK is supplying our habit with a new release of M5 material. Last week it was this video. This week it’s a treasure trove of images that make us lust after it all the more. You can check them out (in Wallpaper size) after the break.

Leave it to the Brits to give us the most insanely hoonish official M5 video yet. Check it out after the break.

Don’t worry. We won’t ruin it for you like other sites out there. But we do want to advise our readers that you should pick up a copy of the latest edition of EVO. Not only is it the annual ECOTY issue (EVO Car of the Year) but it also features the a couple of M cars prominently. And if you’ve been following EVO this year then you’ll know that the M5 and 1M are held in very high regard but what many proclaim as the best automotive magazine on the planet.

So go grab one at your local news-stand. Or better yet buy the iPad version for much cheaper.

However first you’ll want to go check out the 1M and M5 videos on EVO before you get the mag though. They are brilliant and give you some glimpse into where they ultimately end up in the voting.

Subscribe | Download (45 MB MP3)

After a very long break we’re back with our biggest and longest show ever. We start with the M5 and new 3 Series and Michael’s first-hand experiences with both cars. And as much as that could be a show in itself, we move on to tackle pretty much every other major BMW topic from the last three months. The show runs a little over an hour and weighs in at 45 mb but it’s one you won’t want to miss.

Here’s the full list (after the break).

• M5: Engine diff and the truth behind the M5′s sound enhancement
• F30: We talk design and equippment
• Active E: Quick review
• 650i/640i Coupe + Convertible (Yes we finally found a 6er to love)
• Z4 2.8i + 528i: A four cylinder to be proud of
• F20 120d / 118d: Michael gives us his take on the new 1er
• 3 series vs 4 series? We give you some insight from some of our sources.
• 1M Slammed by Motor Trend? Our take.
• M3 Frozen with all M Performance options driven through the Alps (yes we actually did it).
• The new V6 M3? We give you the inside details

That’s all it took Car and Driver to take the F10 M5 from 0-60 mph. We expected under 4 but 3.7 is about a tenth or two beyond our hope. Not bad for a rear wheel drive über sedan. Your turn Mercedes. Oh wait… they already had their turn with the E63 and only managed 4.0 seconds.

You can read more in the latest edition of C&D and you can read our first drive of the car here.

In the hot sun of southern Spain tires can come into question, especially in a performance sedan. The M5 was shod in Michelin Pilot Super Sports and they did an admirable job keeping the car connected to the tarmac both on the street and track. Wear was even and they didn’t get as greasy as we expected. All in all they were an impressive tire and there is some interesting technology behind them. Full release after the jump.

MICHELIN Pilot Super Sport fitted on the new BMW M5 (Press Release)

To equip its new BMW M5 high performance sedan, the Munich-based carmaker has certified the MICHELIN Pilot Super Sport, the world’s fastest street tire on the racetrack (1). The MICHELIN Pilot Super Sport delivers all the motorsports experience acquired by Michelin, notably in the Le Mans 24 Hours race.

All of the new BMW M5 models will leverage the MICHELIN Pilot Super Sport’s leading-edge technology, featuring a unique combination of three components: the Twaron®-reinforced belt, the Bi-Compound tread band and the Variable Contact Patch 2.0.

• The Twaron® belt is a high-density fiber primarily used in aeronautics and protective military gear, whose key feature is its high traction resistance. Strong and light at the same time, Twaron® is five times more resistant than steel at equivalent weight. Thanks to its variable tension, the belt tightens the tread more than the shoulders, so that centrifugal force is more effectively overcome and pressure is more evenly distributed.
• Originally developed for racing tires, Bi-Compound technology uses different rubber compounds on the left and right sides of the tread. On the outside, an elastomer ensures exceptional endurance in tight cornering, while on the inside, a different elastomer combines with a special tread design to enable the tire, on wet pavement, to break through the water’s surface and adhere to even the slightest irregularities in the road.
• The innovative feature of the Variable Contact Patch 2.0 is that the patch changes shape depending on actual driving conditions, thereby guaranteeing total vehicle control. In this way, even as the patch’s shape changes when cornering, the amount of rubber in contact with the road remains the same.

The combination of these three technologies delivers the exciting drive that BMW M was looking for, particularly in terms of precision steering, sportiness and safety, on both street and track. What’s more, the MICHELIN Pilot Super Sport offers superior mileage, one of the brand’s traditional hallmarks.

This performance balance reflects the successful transfer of technology from track to street, as well as the two years of close cooperation with the carmaker on the BMW M5 project. All together, nearly 1,200 prototype tires and 1,000 pre-series tires have been produced, measured and tested in extreme conditions. From the Nordschleife circuit in Germany to the Ladoux test tracks in France, the tires underwent extensive track and street testing. These road trials are critically important to both BMW M and Michelin, as a reflection of their shared commitment to high performance.

(1)The tire recorded the fastest lap time in a dry-circuit test conducted against its five leading competitors in 2010 by TÜV SÜD Automotive, an independent organization, using 245/40 ZR 18 Y and 235/35 ZR 19 Y tires.

Chris Harris attended the same event M5 in Spain as us and he came away with some similar opinions (no surprise there as the car is sublime). He just posted his video diary on “evo” regarding his time in the all new M5. In this video he sets out to answer these five questions:

• Has it got any range?
• Has it got torque?
• Can you not rev the tits off it and still go quite quickly?
• Does its gearbox want to break your neck everytime you change gears quickly?
• Can an M5 really be turbocharged?

The engineers were more than happy to show us the key parts of the M5 rear suspension while putting one up on a lift. What that means is that we snapped some of the first shots of the new M5 from underneath. The rear was our main focus as there is a lot of new techniques being used back there and that is where the sound comes from (in theory).

For the first time in an M5 the M engineers have essentially completely redesigned the rear suspension compared to the base 5 series model. There is extensive use of aluminum, and kinematics that are great on the street and even better on the track. Taking new techniques that were learned building the track rat M3 GTS, M made the M5 rear suspension one of the most compliant we’ve ever driven and that is saying a lot considering how much torque the S63tü is sending back there.

By hard mounting the suspension directly to the rear mounting points they sured up a weak link for performance. They couldn’t stop there, they need to add smaller amounts of rubber lower in the suspension to take out the harshness and vibration so it would not make itself known in the passenger cabin. It was a huge success as the road feel is there but there is none of the vibration or noise common in solid mount applications.

Check out the Photos and the captions for more details. The tiny size of the rear mufflers is also worth noting, the car sounds good on the outside as you’ve heard here before.

During our time with the M5 in Spain we were surprised by the new differential, which is called the Active M Differential (no surprise there). It was quiet, played nice and was seamless in its ability to shift power from the wheel with slip to the one with grip.

According to information we’ve received, it has limited parasitic loss and is just one of the many components that helps the new M5 achieve outstanding performance while improving efficiency. We have broken the complexities down as best we can. It is an amazing piece of hardware.

The Active M Differential is the next step in giving the rear wheel drive chassis more control and stability. Rather than requiring slip, like a viscous differential, the new system can be proactive thanks to the use of electronics. It interprets data from the Dynamic Stability Control to provide the optimum locking force to each wheel all before a wheel breaks free.

In addition to using DSC the system the Active M Differential can adapt based on pedal position, rotational speed of the wheels and yaw rate. All this happens extremely fast and precisely. This differential is able to shift power to the outside wheel in a tight turn as well as counteract the loss of traction during high speed lane changes. It can even decrease the tendency to understeer during full load cornering.

It uses some serious hardware and software to accomplish all of this. It all was evaluated and adjusted countless times to meet M’s high standards. With all the added performance there is also increased efficiency thanks to decreased mechanical drag over the outgoing unit.

How does it all work (Engineers and gear heads this is for you!)? It uses an electric motor and clutches to vary the power between the wheels- all controlled by sophisticated electronics.

• Current supplied to an electric-motor connected to a reduction gear directly rotates the cam gear of a unidirectional ball-ramp mechanism
• This rotational torque causes the balls to roll up the opposing ramps which pushes the front cam forward
• The cam thrust is transmitted through the pressure disc compressing the clutch
• The rotational torque from the outer plates (input) is then transferred to the inner plates (output) proportional to the electrical current
• An Electronic Control Unit (ECU) controls the clutch torque by adjusting the amount of current based on available vehicle inputs (DSC) and a custom control algorithm
• Optimum release response is achieved by back driving the electric-motor
• The low drag torque performance is achieved at all speed differences since actuation is independent of the speed difference (unlike in a viscous unit)
• Torque transfer is mechanically pre-emptive and does not require any speed difference to activate (electronics)
• Full and continuous lock-up is available (0.5 A current)

Before we dig in and let our views on this highly controversial subject fly we need to take a trip in the not-so way back machine. The year is 2009, and we are at Road Atlanta for the X6 ///M launch. The inter webs were full of hate towards this vehicle for taking ///M to turbo charging, SAVs and all wheel drive. These were a lot of things a lot of people wanted to hate but they also didn’t want to learn or look deeper into what M was doing with this and the X5 for the future of performance and the brand.

Taking the X6 ///M on the track, putting it through its paces and being amazed at how well it drove at 10/10ths there was little for journalists to bemoan except the huge weight, the soundtrack that came out of the exhaust and the limited sound that entered the cabin. The X6 M introduced many of us to cylinder deactivation on shifts but that combined with the cross bank manifold and strange firing order of the S63 created less than a harmonious sound. Many including us referred to it less than affectionately as a burp or even worse, a flatuant.

So not only did an ///M have to perform on the track but it needed to be luxurious for day to day driving; quiet and smooth while also still sounding like and performing like a race car when the driver demanded it. You can now see the dilemma, how can a brand be so many things at once? The engineers spent the next few years trying to solve that while developing the most sophisticated, efficient and fastest M5 ever.

In late 2010 I recall my first aural encounter with the F10M on the ‘Ring thanks to some spy video. First thing I noticed was there were no more burps, just a deep wail and it sounded good. As time rolled on I heard more and more of the exhaust from the outside of the car. Our latest experience was at Leguna Seca where we were lucky enough to grab some video. Call me impressed, they did a great job tuning it to be a baritone in a symphony.

Having driven the 550i a good deal, I was aware that the F10 is extremely quiet on the inside, a little too quiet so I wondered how the M team would be able to get the sound into the cabin and not break any laws for sound on the outside. Then came my recent experience at Ascari with the F10M.

Sitting trackside the boom of the exhaust was great, no hiccups, burps or whatever just pure sound from a turbo V8. It sounded good, not the great staccato of the M3 but it sounded like a proper M car. There is no use of cylinder deactivation in the S63tü, the engineers use the Valvetronic system to retard things just enough to lessen the load on shifts so the drive train gets a little less monster to deal with. This helps the sound immensely. When I and a few other journalists asked to have the car put up on a lift to check out the under side (coming soon!) there were only mufflers in the rear. There were no intermediate cans and the catalytic converter is high up in the engine. That creates a smoother flowing system with less restriction but that also means there is nothing to resonate under the passenger compartment. An ideal solution good for quiet.

Driving through a tunnel or windows down, the exhaust music is good and at a good volume for most. Once the windows are up you’d be hard pressed to know you were driving a performance machine unless high in the RPM range and under load. I’d say that most enthusiasts would complain the car is too quiet in this regard and is why the engineers looked at what they could do to pipe in sound. The Indianapolis Colts of the NFL have been accused by visiting teams of piping in extra crowd noise at key points in the game, they do it to win and please their fans- M is doing something similar to please the limited group that likes car exhausts.

Sadly, there are not many people left that like the sound of an internal combustion engine, let alone one that revs high and is free breathing. I hate to say it but we are the minority. Most people are used to the Lexus/Toyota way of life, cars are appliances and they should be quiet. The fact of the matter is that this car really has no place to put another resonator or to move the cat thanks to the base 5 Series design, the buyers of these cars tend to want luxury first and performance second. But M still believes that performance comes first and they can always build in the luxury just sometimes it is more difficult.

The point of all this is, that with Active Sound Design, M has not taken the aural experience of the exhaust away. They are just piping it into the speakers so it is more audible inside more or less when the car is in “Sport” or “Sport Plus”. I have no issue with this as they are not altering anything, they are not making a car with a lousy exhaust sound better (like other brands). They are just bringing the outside in. The other alternative is to make the outside louder and that was just not an option because of EU regs as well as the car would garner more attention and that is not its purpose.

At the end of the day it sounds great and without the press release or journalists discussing it, most would never even know what was going on. It just sounds like an exhaust and the cars real exhaust note- I am a fan. I’d go as far to say that I wish they had this on the M3 so I wouldn’t need to drive with the windows down in sub-zero temps just to hear the full glory!