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  • Apexcarver

    Jan. 14, 2009 11:38 a.m. Apexcarver UltraDork

    found something interesting that at the same time leans towards an answer but dosent answer it directly..

    Porsche used cross-drilled rotors with mixed success. The Zimmerman rotors used on the 930 Turbo brakes were very soft and crack prone, even though the holes were chamfered. The later Brembo rotors will also show some wear when used with most performance brake pads. Some of the best rotors in the world are made in Britain by AP and Alcon. Those rotors, when properly adapted, seem to be superior to the Brembo ones in terms of wear and crack resistance. All drilled rotors will crack sooner or later if overheated. Slotted rotors are more durable in this regard however they are heavier. One reason that most large iron rotors are cross-drilled is to save some unsprung weight. Since nice big, light, carbon rotors cost $1000 each, saving some weight without bankruptcy, is important. Plus, carbon rotors possess very little friction until they reach 500-600 degrees F. Porsche's PCCB ceramic matrix rotors while very light, seem to have mixed success when used for track events.

    http://www.rennsportsystems.com/2c.html

  • poopshovel

    Jan. 14, 2009 1:12 p.m. poopshovel Dork

    Wally wrote:

    June 2008 GRM, "Think Globally, Stop Locally: A Systems Approach to Brake Component Upgrades" is quite possibly the best. brake. article. ever.

    That article changed my life

    That article increased the size of my whang by 3 inches, and made me a gazillionaire.

  • noisycricket

    Jan. 15, 2009 12:46 p.m. noisycricket Reader

    93celicaGT2 wrote: Then i guess my next question is.... why exactly do we not hear of Porsche rotors cracking? Better quality/metal more suited to the drilling without losing strength?

    Probably the prime reason is that the typical Porsche owner never even gets to 50% of the car's braking ability in an emergency stop, let alone regular banzai braking on open track.

    Porsche OEM crossdrilled rotors do crack. They're not magic or anything

    PS - The Cobra rotors above look awesome. I had a Nissan that would turn the rotors the same beautiful bluish/purple colors but never managed to crack one. Not for lack of trying, though. I like to say, if your rotors aren't glowing yellow, you fail as a driver...

    edit: fix Angry Whopper fueled typos

  • Jensenman

    Jan. 15, 2009 12:49 p.m. Jensenman UltimaDork

    Wow. That Corner Carvers thread spans THREE YEARS. And we think the 'Ignore' thread is long lived.

  • 93celicaGT2

    Jan. 15, 2009 12:55 p.m. 93celicaGT2 Reader

    noisycricket wrote:

    93celicaGT2 wrote: Then i guess my next question is.... why exactly do we not hear of Porsche rotors cracking? Better quality/metal more suited to the drilling without losing strength?

    Probably the prime reason is that the typical Porsche owner never even gets to 50% of the car's braking ability in an emergency stop, let alone regular banzai braking on open track.

    Porsche OEM crossdrilled rotors do crack. They're not magic or anything

    PS - The Cobra rotors above look awesome. I had a Nissan that would turn the rotors the same beautiful bluish/purple colors but never managed to crack one. Not for lack of trying, though. I like to say, if your rotors aren't glowing yellow, you fail as a driver...

    edit: fix Angry Whopper fueled typos

    Ah hah!

    My quest has ended.

    And i wish my rotors would do that. :(

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