The drivetrain is a collection of parts including the transmission, the driveshaft, the axels, and the wheels. It was originally developed in Motorsports where two separate drivetrains, each with its own clutch, continuously transfer engine power to the rear wheels.
Drivetrain Gear Change
In the BMW drivetrain system, one of the drivetrains is set for the even gears (2,4,6) while the other drivetrain is set for the odd gears (1,3,5,7).
For example, when changing gears from the second to the third gear, the third gear would first be engaged in the inactive drivetrain. So, when disengaged from the second gear by switching up, the third gear is already next in position. By overlapping the clutch and declutch, the transmission of power remains uninterrupted.
The entire gear changing process happens within a matter of milliseconds where each upshift in gear increases the speed at a steady rate.
High thermal heat loads typically develop in the drivetrain in a high-performance sports car. The engine oil is kept within the optimum temperature range. It is not just cooled via the engine’s cooling water circuit. Instead, an additional oil and air cooler are installed to help avoid excessively high temperatures inside the M Double-Clutch Transmission.