Anybody using drilled and/or slotted rotors?

#1

There is lots of posts on here about entry level priced rotors. Does anyone care to share any feedback if you’ve tried a drilled and/or slotted rotor? Good, bad, indifferent…

#2

I’ve had bad luck with drilled rotors on other cars so I have never tried them on the Spec E30. The holes cause stress concentrations as the rotors heat cycle and can lead to premature cracking. I run really cheap solid rotors with good success.

#3

Likewise, I run cheap stock rotors. I look to see who has them on sale and pick some up. Drilled/slotted rotors have less total mass and like Fish said, generate premature cracking around those areas.

#4

+1 on drilled rotors cracking early. Slotted rotors don’t normally crack early, but they go thru your pads faster for no good reason.

Old school pads had outgassing and glazing issues. Holes gave the gas somewhere to go. Slots scraped off the glaze. Very carefully done both still have some utility, that’s why you still see some drilled or slotted rotors in high end race cars. From the perspective of DD or spec racing tho, it’s just marketing.

#5

I think drilled rotors are for the same guys that paint their calipers red…

Al

#6

Drilled rotors are plain silly.

Slotted rotors do add torque and help the pads but not at world stopping proportions. TO make a better rotor you should go after the material and the casting design - but that costs $$ and is not visible and is thus ignored to save material and time.

Our Spec E30’s are too slow to really extol this so for now china = cheapest and it works.

-Ken

#7

I run slotted rotors and believe there to be some benefit in feel and consistency through the brake zone. I found a source that is as cheap as blanks. I’ve run only one weekend on them so we will see how they do this weekend at Watkins Glen. I ran 1 set of slotted rotors all year last year and they finally cracked when I got the car home from Nationals. That’s getting every bit out of them :wink: