Contour Enthusiasts Group Archives Forums Modifications Brakes cross drilled rotors

are cross drilled rotors worth it am going to need breaks very soon just wanted to know if crossdrilled rotors are any good or to much trobble.

Cross-drilled rotors, in any typical street application, do nothing for performance and are for looks only. In fact they offer increased susceptibility to cracking over time.


Do a search for cross drilled rotors in this forum.

Although I have no experience with actually using cross drilled rotors, adding to the comments posted above, I would assume that the holes and such on the surface of the rotor would eat away more at the brake pads than your standard smooth rotor. Seriously, for normal driving conditions standard rotors are perfectly fine. Most street drivers get cross drilled rotors for the look.

I can also tell you that more than likely most shops that do rotor resurfacing will not turn the rotors down for you either if they warp or wear. Our brake lathe at the shop used two blades (one for each side) that were shaped like triangles. I never turned any cross drilled rotors, but I could almost imagine what would happen to the tips when it hit one of those holes. You'd more than likely get the lathe to lock up and blow a breaker. So most machine shops with those types of lathes probably won't touch them. Just something to think about.

I have a cougar but, I always had problems with my rotors warping when I had my stock ones. Also for some reason my pads would wear down really fast. I changed to omp slotted and crossdrilled and I haven't had any more problems with warping. I thought my pads would wear quicker because of the holes and all, but they haven't. I've had the same pads on the car for over a year now and when I checked a couple weeks ago they still looked perfect. Also when I have to break hard, my breaks don't work like crap for a while like with the old rotors.

Also, my driving habits are the same now as when I had stock rotors.

When I was working at midas, this guy I worked with used to work at breaks plus. He told me about this circular diamond blade they used over there. Think that would grind a cross drilled rotor?

I strongly agree that drilled rotors are just for looks and do little or nothing for brake performance. As already mentioned, the holes provide stress risers for the rotors to crack and indeed they are much more prone to cracking.

Drilled rotors, however are not difficult to machine. If someone says they would rather not machine them it is probably best that they don't try. I have machined many. It is best to take a lighter cut than you may want to if you were machining plain rotors. Some companies that drill rotors claim that they countersink the holes deep enough to somewhat reduce the cracking problem as well as make them easier to machine.

Thanks for the insight, arskiracer and Big Jim. It helps to read posts from people who actually have them on their car and/or have had more knowledge or experience at machining them.

I have heard from different people about the circular diamond blade that is incorporated on the newer lathes. I would make the assumption that its circular shape would glide over the holes making turning these rotors possible, but I have yet to see one of these machines in action before I can judge for sure. Even more helpful would be to actually see it turn a cross drilled rotor. I just know that a lot of these smaller shops (especially where I am from) still use the older style machines and the owners see no need to convert. When I was first learning the lathe, I turned a regular rotor and hit a small imperfection. Instead of bypass it, the tip caught it locking up the lathe. That's why I assume that a cross drilled rotor would not work on a lathe with the triangular tips. But I would like to see the ones that incorporate the circular diamond blade in action.

I've turned both drilled and slotted with no problems.
The feed rate and cut depth are the key to making them work.

As for triangle tips vs. round ones, I can't speak for the round ones, but the contact point is going to be the same. I can't see these making much difference. Locking up a brake lathe on a cut is an indication to me that the cut depth is waaayy too deep. Slow speed and about .002-.003 and you'll cut them just fine.