Rotors: Drilled or Slotted

Im looking into swapping my current rotors (99 cobra) over to a more performance set up and different pads. Ive havent had enough experience with either, but so far ive heard good vs bad things about both cross drilled, slotted, and both. Crossdrilled ones can (will) crack and wont last as long, where slotted use up your pads real quick. Any truth to the chaos? Im looking into brembo 13s and 11.65s with upgraded ceramic pads, wanting both performance and endurance.

I would not run drilled discs.

I do run floating sloted discs though. Basically the biggest rotor(disc) you can find, will stop better. Take material away, it decreases it ability to disipate the heat.

...but so far ive heard good vs bad things about both cross drilled, slotted, and both. Crossdrilled ones can (will) crack and wont last as long,...
The problem with CrossDrilled vs. Sloted lies not with the machining process, but with the quality of metal used.
For example, a pistol made of billet steel will not explode in your hand as would a pistol made from cast iron.

In a nutshell, I've owned Stillen Cross Drilled Rotors and they have not cracked with more than 50,000 miles on them.
I have seen cheap PepBoys cross drilled and they are garbage.

The problem with CrossDrilled vs. Sloted lies not with the machining process, but with the quality of metal used.
For example, a pistol made of billet steel will not explode in your hand as would a pistol made from cast iron.

In a nutshell, I've owned Stillen Cross Drilled Rotors and they have not cracked with more than 50,000 miles on them.
I have seen cheap PepBoys cross drilled and they are garbage.


This is true to a point.

Any drilling into a piece of metal will fatigue it.

And like I mentioned, holes in the rotor will decrease its ability to disipate heat, which is what actually stops the car:)

Why does Porsche use them on the 911's?

Porsche does not drill their rotors, and they are very expensive.

Everyone brings up the fact that Porsche uses those types of rotors when this subject comes up.

Eillob, do the research and come and tell us why they use them.

What kind (brand) of slotted are worth the buck? Also, any brand preference for the pads?

Ok Skyline here's what I found. The new 911 GT3 comes with Porsche patented crossdrilled rotors. Take a look http://www.germancarfans.com/news.cfm/NewsID/2030422.001/porsche/1.html

For the most part you are correct most Porsches don't come with cross drilled rotors but there are exceptions.

Heres some good info I found for this thread.

http://www.autoaccessorystore.com/resource/brakes/rotors.asp

http://www.automotiveforums.com/vbulletin/showthread.php?t=85221&highlight=brakes

I spent some time on this one, read it.

http://www.automotiveforums.com/vbulletin/showthread.php?t=85221&highlight=brakes

I spent some time on this one, read it.

That, was a good thread.

Like I said, I spent some time on that one.

It's funny when that one guy that was not agree with me, then realized what I was saying was right.

I would not run drilled discs.

I do run floating sloted discs though. Basically the biggest rotor(disc) you can find, will stop better. Take material away, it decreases it ability to disipate the heat.

I choose to side with Moppie on this one! Both of you make this easy to understand, and so far, Skyline, you have gotten me to pick up some oversized slotted rotors. Thanks a lot!

Your welcome http://www.modularfords.com/forums/images/smilies/whistle.gif