Seven-speed S tronic

The drivetrain is a special highlight of the new R8* technical concept; it features a seven-speed S tronic that executes gear shifts within hundredths of a second and an intelligent quattro drive system that provides maximum stability and dynamism on any road surface. Audi is presenting the latest state of it technology here.

The seven-speed S tronic is standard with both engine versions – the V10 and the V10 plus. Operating commands are all transmitted electrically (shift-by-wire). The driver can manually shift gears using the gear selector lever or the shift paddles on the steering wheel. Or the driver can have the S tronic shift automatically in the D or S program. At the push of a button, the driver can start off with launch control which engages the clutch at around 4,500 rpm – it applies the power of the V10 to the road with perfectly controlled tire slip.

Based on its three-shaft layout with one dual drive shaft and two output shafts, the seven-speed S tronic mounted behind the engine is very compact. Its thermal management, which coordinates with the engine, uses an oil-water heat exchanger that is mounted to the transmission. The mechatronics, which are set up as a separate block, activates and lubricates the high-tech transmission. One oil pump suffices to supply oil to the gear wheel sets, clutches and integrated differential lock.

Two multi-plate clutches, one behind the other, operate two independent transmission sub-units. Clutch K1 transfers the torque via a solid shaft to the fixed gear wheels for gears 1, 3, 5 and 7, which are located in the rear section of the transmission housing. A hollow shaft rotates around the solid shaft. It is connected to a second K2 clutch and acts on the gear wheels for gears 2, 4, 6, and reverse. Mounted on output shaft 1 are the gear wheels for gears R, 4, 5 and 1, while the gear wheels for gears 2, 6, 3 and 7 are mounted to output shaft 2.

Both transmission sub-units are continually active, but only one is connected to the engine at any one time. The shifting process runs so smoothly and comfortably that the driver hardly notices it. Gear shifts take just a few hundredths of a second, and they are executed with nearly no interruption of propulsive power.

On output shaft 2, the seven-speed S tronic has a connection to the propeller shaft that runs through the bed plate of the dry sump oil pan to the front axle. An electrohydraulically activated and electronically controlled multi-plate clutch is mounted there, forming a block with the front differential.

The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.