Cross-Drilled & Slotted Rotors

Concerning cross-drilled rotors...

I just read in the October 95 Road & Track that cross-drilled rotors are not necessary for street driving. They don't help ventilation that much and actually chew the pads quicker. Plus the rotors wear quicker. Pretty much, stick with the Nismo upgrade. If you need more than that, try the GRIP rotors.

Comments by Merlin Johnson

Cross drilled rotors are good when your on the edge all the time, like racing, they might give you that little bit of extra cooling....after the rotors are really hot though. By cross drilling for the street you are removing some of the precious metal that can be used as the heat sink for lower temp braking. Cross drilling can produce stress cracks, chamfering reduces this a bit. They are mainly for looks on the street, but they do look pretty cool. If I had gotten the warm fuzzes from other brake manufacturers on cross drilled rotors I would have jumped all over them long ago.

Comments by Ioannis Nanakis

Cross-drilled rotors are also supposed to remove better the debris and gases between pads and rotors that are produced during (hard) braking. So they help the pads to be in full contact with the rotors all the time. In theory they are supposed also to improve braking action because the holes deglaze the pads.

Comments by Carson M. Hanrahan

I *had* cross-drilled rotors, but stock size, on my `91 SE-R. Not much difference at all in braking. But, upgrading to the Nismo brakes, even though they're not cross-drilled, WHOA! *Big* improvement. Even the reasonably heavy street driver won't need cross-drilled rotors with the Nismo upgrade.

Comments by Thomas Paule

I have $tillen Cross Drilled rotors, metal master pads, and 16" Antera 123s, here's my impression:

Initial brake bite is substantially improved, but overall brake performance in the street is just slightly improved.

On the track, the pads did wonders, not fading one bit for a full day of racing at the Streets of Willow POC event this June.

After my second POC event at Willow, I had cracked my front right rotor pretty badly, and my pads finally gave out a few days later (after 50 THOUSAND miles!).

I would recommend the Metal Master pads, I would be cautious about the Cross Drilled Rotors, though. Mine showed crack for a while before really getting the "Big One" a few weeks ago. I'm sure it helped that my car is in LA, where it hardly ever rains, thus keeping cool water from increasing the small cracks that started without the water.

What does slotting buy you over cross drilled or normal rotors?

Comments by Merlin Johnson

Slotting is really the best way to try and add extra venting to the rotors. The slots are made in an arc that goes from center to outside, gas can escape easier because there is a tendency to "throw" it out from centrifugal force. It's a small difference, probably not noticeable unless you are constantly on the edge (you get your rotors red hot).