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      07-19-2012, 02:15 PM   #21
admranger's Avatar

Drives: 2011 M3, 2016 X5 40e
Join Date: May 2011
Location: Alexandria, VA

iTrader: (0)

So in my 10+ year BMW club racing career, I replaced a lot of brake pads and rotors.

I'd experience about 0.001" - 0.002" of wear on the front rotors, depending on the track.

I usually ended up replacing rotors well before their wear limits as they would develop surface cracks that would catch a fingernail (highly calibrated instrument). Once a surface crack that large was detected, the rotors came off and were tossed into the scrap pile.

I never ran drilled rotors.

Now that I have retired from racing, I have more money to spend on the daily driver/track car (E46M3). I put on PFC direct drive rotors all around and they are ridiculously good (both in runout and durability). Expensive? Yes. Worth it? Yes, in my opinion.

The E90 M3 has one track day on it and less than 7k miles, so I'm not too worried about the rotors yet. Once the warranty period rotors are gone, then PFC direct drive rotors will be put on.
'11 E90 M3, Mebourne/Black/Fox Red/Black, 6MT, PP2, heated seats, moonroof, split folding rear seats, iPod/USB adapter, Dinan F sway bar, Arc-8's, Technic harness, JL XD 6/600.

'16 X5 40e, Mineral White/Black Dakota Leather, ZLL, ZCW, ZDA, ZDB, ZPP, multi contour seats, HK