BMW explains why it’s manual transmission E60 BMW M5‘s DSC stability control cannot be disabled. The issue is with the huge amount of power and torque that the engine outputs – it causes excessive axle tramp.
What is axle tramp exactly? Axle tramp is when a wheel moves up and down very very violently, with such force that it actually leaves the ground – like a car hopping. A problem with putting power down to the wheels, worse than torque steer. It is caused by the axle rotating slightly with the wheels then springing back repeatedly.
With the 7-speed SMG III-equipped E60 BMW M5, BMW could fine tune the operation of clutch plates to combat axle tramp during crazy tyre burning starts even with DSC off, but this was just not possible with a pure manual gearbox with a pedal-operated clutch. BMW’s solution – leave DSC permanently on but offer a mode that is less intervening called M Dynamic. Which makes me wonder, why not somehow set up the engine to limit torque delivery in the first gear, so that traction control can be fully off in all the other gears? Did BMW’s engineers miss something here?
E60 BMW M5 now with manual transmission