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Old 05-12-2005, 12:46 PM
spta97 spta97 is offline
Officially Welcomed to the 'Fest
Location: NY
Join Date: Aug 2004
Posts: 128
Mein Auto: M3 ZCP on order!
Originally Posted by bren
They can't be "one solid structure" with holes in them.
Here's a quote that explains it better:

"The drilled rotor so common on the Porsche 930 turbo is NOT really drilled at all. It is a CAST hole. Porsche did this to help minimize the effects a hole has in creating a stress riser in the surface of the brake rotor. A drilled hole goes directly through and interrupts the grain structure of the metal. Where as a cast hole has the grain structure formed around it in an uninterrupted flow. All holes in a brake rotor will eventually show signs of stress cracking. A drilled hole will crack much sooner than a cast one"

Originally Posted by bren
I guess it's your lucky day.
From the Competition package PDF

"The cross-drilled, compound front rotors have been increased to 13.6" (up from 12.8"). "

I do not see any mention of the rear rotors being cross-drilled as well - is BMW incorrect?

Originally Posted by bren
Don't worry...the car is not intended for track use.
Again, reading the Competition package PDF:

"The M3ís already powerful brakes have been improved to meet the demands of repetitive hard braking experienced on the track."
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