Holes in rotors usually develop stress cracks under exterme use...

Here's a pic of the rotors run by one of the World Challenge teams I help.

They are Performance Frictions:



Another team I am associated with runs AP Racing brakes. AP is now owned by Brembo.. link:

http://www.apracing.com/info/index.a...rake+Discs_976

You might want to peruse this Brembo link...

http://www.brembo.com/CatalogoRacing/2007/index.html

Here's a handy reference to disc face types.

http://www.apracing.com/info/info.as...+Face+Types_39

My point is, drilled rotors are fine for street uses, but so is a smooth faced rotor. Slotted is just a better deal for extreme usage.

Extra machinig means extra money. Cross drilled rotors are predominantly a looks thing. If you want to pay the machining bill, pay for results over looks.

 

How about brakes for the Porsche Carrera GT?

http://www.autocult.com.au/img/gallery/5BBYD3JR.jpg

I have been told that Porsche originally tried the holes in an effort to lighten the rotors.

But it appears that most real racecars don't have any slots of holes in them.

 

Dammit! I've lived in the world of drag racing for so long that I can't help but to think in seconds versus minutes. It's like trying to think metric when theres nothing but SAE tools lying around.

How about sub 480 second lap times?

 

Yes? They are carbon-ceramic (silicon carbide) rotors on a STREET car.

They are light and stop very well.

I know someone who was involved in their validation, but that's all I can say about that.

Porsche made some lofty claims about their longevity when they released the car.

In some instance the specifications haven't met the expectations when the cars have been run hard at road courses.

{ looks like the photo is on a flatbed wrecker, too bad }

The CGT is not one of my favorites. It's pretty prone to snap oversteer.