[DaveZ]

My 2017 OG M2 is new to me and this evening I had my first relatively high speed experience in heavy rain. I thought there was supposed to be automatic brake drying when the wipers are going, but every brake application was excruciating in how long it took to dry the brakes and get some grab. I came to the M2 from a 2006 Z4 M Roadster with drilled floating rotors like the M2 and which had a great brake wiping system. Even in heavy rain, the Z4M brakes would grip instantly. I expected that with 11 years of technology progress the M2 would be even better, but tonight it scared the sh*^&$t out of me with how long it took the brakes to grab. I just read on another model forum that the brake drying feature may only activate when the wipers are at the highest fixed speed, while I always use rain-sensing auto mode. Could this be the issue or am I just expecting too much? Like I said, the brake drying feature worked terrific on my Z4M at all wiper settings.

[QM]

Good question. I don't have the answer, but I do notice this every time I drive out of a car wash. First break application is always weak.

[M Fifty]

"Brake Drying" ???

[ZM2]

Originally Posted by M Fifty

"Brake Drying" ???

You haven’t seen the little hairdryer connected to your brakes?

[5.M0NSTER]

Brake drying is a feature which ever so gently applies the brakes cyclically (think like 1-3 bar of pressure) when rain is detected by other systems.

The goal is to wipe the brake discs of excess water so that if you need to jab on the brake pedal for emergency braking you don't waste 3-4 rotations of the wheel just to get the pads to touch the disc instead of riding on water layer.

It is not really brake drying, it is excess water removal. It doesn't warm the surface of the rotor or pad, it doesn't completely dry the pad or the disc. It helps by removing excess water only, and saves 8-12 feet from your stopping distance otherwise.