Sleeper_08

I'm thinking of getting my rotors turned before the next season of raod course track days. They are not bad but do show some wear and grooving. I'm also going to install new pads.

My Hayne's manual says "The manufacturer recommends that any disc refinishing (machining) be performed with a specialized brake lathe that can cut the disc while it is still installed on the vehicle. They caution against using any other type of machining process to refinish the brake disc".

Has anyone had disc machined this way? How did it work out and roughly how much did it cost?

Has anyone had the discs machined off the car? If so were there any other problems?

Any other comments or suggestions will be appreciated.

I know new discs are fairly cheap but not for GT500 fronts in Canada.

157dB

One the vehicle only accoriding to the Ford Workshop Manual.
I would go with new rotors myself.
Cheap and easy with no worry about runout.
You bought a GT500 and must now pay the price to own a GT500.

Sleeper_08

Per my sig and avatar the car is a GT but it has GT500 front brakes.

my77stang

don't listen to the first guy, you can get rotors turned multiple times until they are worn beyond the minimum thickness spec of the rotor. i know by me, its 10 bucks a rotor to turn em.

Texotic

I took mine off and took them to O'Reilly's to get turned. I've got an odd noise coming from the rear axle, though, but thought it was the clutch packs in my LSD, maybe I need to check and make sure my rotor is still on correctly. I don't really get why you couldn't do it off the car, though... I didn't realize the shop manual said that... I haven't seen any problems yet, though.

charliebrown266

I would not resurface them,the more material you remove from the rotor the thinner they will be and more likely to warp!If you were only using it has your daily driver i would say try it.But using it at the track for road racing or track days i would not because of the heat being created.

my77stang

you guys DO realize that when they turn the rotors your not loosing crap for metal, and that if he's road racing he's just gonna burn up a new set anyways?

*sighs*

clintster77

I don't know the correct procedure on actually turning them , but with a Gt500 kit I think that as long as you stay within the recommended thicknesses you should be ok . also if you are going to buy a new set I would get one last use out of your old ones. Turn em to the maximum and save some weight .hahahaaa

Philostang

+1 for 77!!

There's a great many confusions regarding rotors, starting with "warped rotors." Do yourself a favor and start reading some decent tech articles, at least you'll feel better about whatever decision you make. I would recommend StopTech's "White Papers" (http://www.stoptech.com/tech_info/te...e_papers.shtml)

Please note the entry: The "Warped" Brake Disc and Other Myths of the Braking System

I don't know why the Haynes manual said that, so I won't say it is right or wrong. I will say I've had front and rear sets of OEM rotors turned down at my local shop ($10 ea.), and I run them at the track. I've not had any problems beyond the normal accelerated wear you have to expect from tracking your car (and poss. using more aggressive pad material).

FWIW, even if you had your rotors turned down near the limit, I don't think you have to worry about "warping" your rotors more than you have to worry about them cracking. Thinner rotors won't tolerate the build-up of heat in them as well as thicker ones, and they begin to form stress cracks (so-called "warping" isn't the problem). That will eventually come, and if you're not watching them they just keep growing to an unsafe size. I stop using a set of rotors (regardless of remaining thickness) once the stress cracks get to be about 3/4" long (maybe 1" if I only have a session left in the day). I've seen folks pay no heed to their cracks and it ain't pretty. You probably aren't going to feel a stress crack at the pedal, so you have to actually look at the rotors.

Your car isn't going to keep itself together by magic or wishful thinking. Pay attention to what it's telling you at all times. Tracking your car is the most fun you can have with your clothes on, but a "joy ride" it is not. Be safe, have fun, and drive hard.

Best,
-j

jayel579

Sleeper, you are doing track days on your car so you have to know by now that the most consumable items on your car are pads, rotors, and tires. Rotors aren't expensive just buy a new set, how much is a new set of front rotors in the scope things, 50-60 bucks? Track pads just eat up rotors anyway, I don't there is really anything to gain in the long run.