mikegarrison

I've got a few sets of brake rotors that probably can be saved if I resurface them. I've read that Blanchard grinding is the ideal, but a fair number of people seem to recommend just putting a very rotor-unfriendly race compound on and driving it on the street for a few days. Hawk Blue seems to be a leading recommendation for this purpose.

So what are your experiences? If any of you have gotten rotors resurfaced, did it work? How much did it cost? If you tried the race pad method, did that work? What pads did you use?

ellisnc

As a general rule, you don't want to resurface rotors for track use. The purpose of the rotor is to absorb heat before putting the heat into the caliper. The less mass you have to absorb the heat in the rotor the faster you'll over-heat the pads and fluid.

That being said, if you're just going to use them on the street you'd probably be fine. I've had some rotors turned at NAPA before and it was like $8 each. Not even close to the cost of some Blues...

Wildncrazy

I always tell them to turn them as little as possible which usually means they do several thin passes. If you don't request it most guys just crank the dial down a long way and make one very thick pass. There doesn't seem to be any science or measuring to it.

Ludedude

The proper way to do it is one fast deep pass to remove the peaks and valleys followed by one slow shallow pass to clean it up.

Mike: If the rotors aren't scored too bad and you plan to run them on the street I'd leave them alone. For the track, if you already removed them from the car for track use, why would you consider putting them back on? If they were too worn to use already, removing material from them is not going to make them better

mikegarrison

They are track rotors, and they aren't "too worn". They work fine when cold, but when they heat up they start vibrating really badly. My assumption here is that I overtemped my brake pads and they left some mismatched pad material on there. But I'm not certain. They are in good enough shape that I really don't want to toss them out and pay $80/rotor to replace them.

rlaifatt

You could probably determine visually, or by running your fingers over the surface, if there are pad deposits. One other possibility for the shudder is if the rotor isn't completely flush with the hub because of some debris etc.

124Spider

Mike, I left pad material on a rotor once before switching to full race pads. The vibrating happened whether the rotor/pads were hot or cold (and went away the next time I was on the track with the pads). Same thing when I cracked a rotor. In both cases, you could feel the problem with your finger on the rotor (when cold, of course).

But for $8 a pad, I'd try a light turning before replacing them. Just bring an extra set of rotors to your next track day in case you don't like the results.

Nobody

I've had a lot of rotors turned. I simply go through too many of 'em to throw 'em out when they get warped. I run Wilwoods and Wilwood themself has said that as long as I can still see a little bit of the slots the rotors are still w/in spec. Plus all those little cracks can turn into big ones if you don't shave 'em off.

Ludedude

There's a specific thickness that needs to be measured to determine if a rotor is in spec and OK to use or not. On my Wilwood two piece rotors, there's no stamped spec but I'm sure they have one published somewhere. "Someone says" is not really good enough for me to trust my life to

If I were Mike, I'd get them turned and make sure they're in spec afterwards. The spec should be listed as a minimum thickness somewhere on the rotor in the case of an OEM type.

mikegarrison

I talked to a local autosports machine shop who says he can grind them for about $25/rotor. That's more expensive than a lathe, but it's also supposed to be better for the final result. I may do that.