cross drilled rotors???

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

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.

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

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

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. :(

Drilled brake rotors are only decent at self-cooling if you buy the quality ones. Lots of times, drill patterns are not symmetrical and are poor for brake balance. Stick with the name brands at the very least, and definitely no eBay.

Slotted rotor are definitely like a heat sink and cool off a rotor like such. If your worried about stress cracks originating from the drill sites, then make sure to pick some with sophisticated edge chamfering to reduce stress points that the pad may create.

Source: http://www.cquence.net/blog/are-all-drilled-rotors-the-same/

ddavidv wrote: And for those of you who may think it is only 'race' cars that can stress rotors to that point, the one on the left looks a lot like the ones removed from a completely stock F-body my friend tracked on a regular basis. I also was able to develop spiderweb cracks in my Audi Coupe rotors after several weekends of use. About a thousand lbs less car. And these are good quality, solid center vented rotors.

shoot, as light as my CRX is I get "heat" cracks in the front rotors .. when they reach the point where I can't stand it any longer I get new ones ...

my first PDX instructor was a Civic (Honda Challenge ) driver... said he just put a new set of parts house vented cast iron rotors on each weekend ... very little money for a lots of peace of mind

Those guys are right, and there was a lot of interesting stuff to read, but ..

Am I the only one who noticed a certain "we are the people who call Rush Limbaugh, still call french fries freedom fries and generally spend a lot of time foaming at the mouth" vibe from the corner carvers?

Just stay out of the non-tech forum and you'll be fine.