Cross drill/slotted vs slotted/dimpled rotors?

[turbovanman]

We had this brought up before but the thread got ugly. Found some rotors on Ebay, I can get each option, these are for my van. Which is the best to get? Keep it clean please.

[mcsvt]

I was trying to find pictures of the brakes on our race car last year, but can't for now.

We made the brakes our selves, actually I sat at the lathe for hours on end taking the metal down...

The design we went with was slotted and drilled. The brakes were very effective. This was on a ~500 pound car though :) I have a friend at performace friction, I can try to shoot him an email and see what they recommend.

[JDAWG]

wtf is dimpled

[turbovanman]

Awesome, thanks Gary.

Dimpled is Cross drilling but not drilling all the way thru.

[Mario]

If you get cross drilled, try to find ones that are cast with the holes, they are less likely to crack. Aftermarket drilled rotors tend to crack easier. They crack because by drilling through a blank cast rotor, the drilling machine creates stress within the metal, which will lead to it cracking sooner. Dimple rotors are ALMOST as god and if they're aftermarket, it doesn't create a stress in the rotor.

[JDAWG]

i dont see how just dimples would help anything, they dont go the whole way through

[mcsvt]

Here is what my friend responded with. He no longer works with Performance Friction. He is now with a shock testing company, but still has some great info here.


Oh about your rotor question, you almost always want to have dimpled or sloted rotors rather then drilled rotors for the reason of cracking. With a dimpled or sloted rotor you are only having stress risers on the surface of the rotor face where the cutout help with keeping the pad from glazing up. When you have drilled rotors you get large stress risers in the rotors which lead to cracking. Possibly the only reason to have holes brake rotors is for rotors that go onto bikes and fsae cars where weight is a huge issue, and often times the diminished weight plays a larger role then the worry about stress risers in the rotors. Make sense?

As for which to use on your street car, dimpled or sloted, at performacen friction all the race rotors were sloted and all the street rotors were dimpled, and the reason behind that was becasue the dimpled rotors made less noise then the sloted rotors.

What car are you trying to put rotors on? you actually might not need them at all, usually a good set of race pads, some SS brake lines and some new brake fluid will buy you larger dividends in terms of braking power then sloted rotors will.

[JDAWG]

wtf are these? http://www.tirerack.com/brakes/brakes.jsp?&make=ATE&model=PremiumOne+Slotted+Rotor&group=PremiumOne+Slotted+Rotor&autoMake=Dodge&autoModel=Caravan&autoYear=1990&autoModClar=14+Inch+OE&perfCode=S

[Mario]

Orbital Slotted Rotors.

[turbovanman]

Awesome info, thanks Gary.


Those rotors are trying to copy the race bike WAVE rotors but doing it a different way. It should work as all there trying to do is vent the gases and the way those grooves are, it should work.

[Mario]

Oh sure, just ignore my post. :lol:

[Frank]

Agree 100% with Gary and his friend!