[LinkF1]

I have less than 50 miles on the car and have a loud and somewhat disconcerning noise coming from the brakes that gets louder as the car slows. It sounds like a jet engine or turbine throttling down. I did some quick research and found this thread from our M3/M4 brethern with the same issue:
http://f80.bimmerpost.com/forums/sho....php?t=1033297

The sound is perfectly portrayed in the video in the second post of that thread around the 6:15-6:25 timeframe. I think it is caused by the pattern on the surface of the brake rotors, as seen in this picture:
http://f87.bimmerpost.com/goodiesfor...80_highRes.jpg

Apparently this sound goes away as you drive the car more and more, but to be safe, I am ensuring the brakes are bedded in properly. If you need tips on how to bed brakes tire rack has a few recommendations: http://www.tirerack.com/brakes/tech/....jsp?techid=85

[HP Autosport]

Will likely go away after a proper bed-in.

[LinkF1]

Over 100 miles in now, the sound is much less pronounced, bedding the brakes seemed to help immensely.

[HP Autosport]

Originally Posted by LinkF1

Over 100 miles in now, the sound is much less pronounced, bedding the brakes seemed to help immensely.

Some people also experience this with new BBK's with slotted or drilled discs.

[Prodigy.]

Mine sounds exactly the same.

[MR.]

Same here, it was gone after 200 KM

MR

[Robin_NL]

Same turbine like noise here. Will go away after a few 100 miles and brakes are bedded in. I did a 'full stop from 90-0' wednesday evening and I think the brakes now know who they have to deal with the first oncoming years

Cheers
Robin