Thread: New Rotors
View Single Post
      01-05-2013, 04:14 AM   #11
mlhj83
Scythe-Meister
mlhj83's Avatar
United Kingdom
29
Rep
1,041
Posts

Drives: '11 E92 M3 DCT ZCP
Join Date: Aug 2011
Location: London

iTrader: (0)

Quote:
Originally Posted by Chagrin
Quote:
Originally Posted by mlhj83 View Post
I use BMW M Sport pads and I've driven them to the point of absolute fade and have never had vibration under braking. I did however have significant vibration under braking when I tried the standard pads on track, which gradually disappeared (2 weeks after track day) as the uneven pad transfer wore off.

I'm inclined to think that yours is also due to uneven pad transfer. It's not something you can easily see. I'm fairly certain that most pads would overheat way before the OEM discs go beyond its maximum operating temperature. Also, once a disc is truly warped - not with axial runout due to pad deposits - it'll never recover, so by the fact that it gets better as you manage the brakes before the next session, points more towards uneven pad transfer.
May I ask if you are using the BMW M Sport pads with the stock rotors? Or do the rotors need to be changed as well?
I'm using them with the rotors that came with the car from factory, and not had any issues (5 track days). I'm aware that there are different OEM rotors specifically for the Sport pads which have different part numbers to the rotors that came from factory, but nobody knows the difference as they look exactly the same; materials might be slightly different perhaps. Best to send an email to BMW customer services for a definitive answer if you are interested.

Oh, I don't use the Sport pads on the road as they are way too noisy - I see pedestrians cringe when I come to a stop. I swap to the standard pads after a track day.