2012 BMW M5 F10: Engine and Transmission Technical Details [Video] image

The 5th generation BMW M5 F10, a wolf in sheep’s clothes – or like BMW M says: a high performance business sedan.

The new M5 is powered by a new high-revving V8 with two turbochargers. 560hp make for the most powerful BMW M engine ever used and a maximum torque of 680 Nm between 1500-5750 rpm.
Internally dubbed S63 it replaces the naturally aspirated engine of the predecessor (E60).

The new engine had to offer more power and torque while reducing fuel consumption. Both intake and exhaust sides have been dethrottled: Air is being channeled from the compressor directly to the intercooler and then on to the engine. The exhaust gases go directly from the turbocharger to the cats.

Michael Menn, Engine Development: “Another advantage of this engine is the fact that we’ve integrated the complete turbo exhaust section into the engine V.

This allows us to combine [the exhaust gases] of these cylinders with as much ignition spacing as possible and thus as little interference as possible. You can see that cylinders of different banks are combined together which was possible due the integration into the engine V only.

This also allowed us to separate the different scrolls up until to the twin scroll turbo. This avoids any negative effects such as back pressure and makes for a very continuous exhaust flow into the turbine.

That way the complete kinetic energy [of the exhaust gases] can be used for the turbochargers.”

Speaking of fuel consumption: It averages 9.91 per 100km in the EU test standard, a good figure for the powerful 4.4-liter engine. The key to this are several efficiency features such as Valvetronic, which controls the intake valves.
If less power is needed, the intake valves open just a bit and less air flows into the cylinder. When more power is asked for the intake valves open further and the engine generates more power.

100kph is reached after 4.4 seconds only, 200kph after 13 seconds. Top speed is electronically limited to 250kph. A 7-speed double clutch transmission takes care of the power transmission to the rear wheels.

Jiirgen Eder, Double Clutch Transmission Development: “This means two transmissions in one. There are two clutches, the inner one for gears 2, 4 and 6 and the outer one for the remaining gears.
Also shown here is the oil supply pump, the oil supply, and the heart of the transmission, the gears. Gears 2, 4 and 6 are placed at the upper transmission shaft, the gears R, 1, 3, 5 and 7 at the lower shaft.”

There are different shift modes for both manual and automatic operation, varying from fuel-efficient to very sporty.

“The heart [of the transmission] is the mechatronic module which also houses several sensors, e.g. pressure sensors, velocity sensors, and touchless position sensors which are able to detect the position of the gears at any time.”

The M engineers have also improved the limited slip rear differential to increase the performance of the rear wheel drive. It’s now driven by an electric motor.

Max Ahme, Head of car technology: “We’re using the engine speed, vehicle speed, yaw rate and other parameters to calculate [the wheel slip] so the rear differential can lock proactively. The rear differential in the predecessor worked based on differing wheel speeds.”

Due to this electric actuation the rear diff can lock from 0 to 100% within fractions of a second. Suspension and brakes are obviously quite important for a car this powerful.

“There’s surely a lot of stress on the brakes as this car has 560hp and 680Nm. We’ve used an M compound brake at the front comprising of the aluminum brake mount, a 400mm vented steel discs and for the first time a 6-piston fixed caliper painted in blue.”

This street-legal high tech race car costs 102.700 C.
[German translation from the video]