It's quite a clever system.
The all-new BMW M3 and M4 are incredibly special sports cars, despite their controversial styling. BMW has been explaining just how special they are in a series of videos detailing various aspects of the Bavarian beasts, whetting our appetites in anticipation of their domestic arrival. In the latest video episode in the series, a man named Karsten (who is responsible for developing transmissions at BMW M), goes through some of the features of the gearbox and how the engineers came upon its design. It's just three minutes of viewing and worth watching if you like learning about technical details in an easy-to-consume format.
As you likely know, the gearbox is a six-speed manual and will be fitted to the regular M3 and M4 models while the Competition versions will feature an eight-speed automatic. The manual retains an H-pattern and now allows you to switch automatic rev-matching on or off as you prefer, regardless of which drive mode the car is in. To maximize stiffness and shift precision, the gearbox is doubly attached to the body. Karsten believes that BMW has one of the best manual gearboxes available, and has decided against optimizing the system any further beyond the aforementioned stiffening. We'll have to drive the cars to see if Karsten is right, but our own experience with BMW manuals has been iffy for the most part, so we hope this increased rigidity improves the way it feels.
The gearbox is lubricated with a dry-sump system for optimal lubrication and features no electronics beyond a sensor to tell the car what gear you are in for the shift assistant to help with rev-matching. The gearbox's input shaft is connected to a two-disc clutch from the F8X models with four friction layers, allowing longer clutch slippage for better launches. A dual-mass flywheel now features a larger starter gear rim and a stronger crankshaft flange with four metal plates, one more than before. This should be good news for tuners that will inevitably seek to extract as much power as possible from the car with stock transmission components. That said, we have no doubt that the new G8X models will be plenty of fun to drive as standard too.