clivew

Hi guys,
I use my 02 Bugeye UK Sti for track days and have experienced the discs warping. I have had them skimmed and they last about 3 or 4 track days before they go again. This has happened now 4 times and it's getting a little frustrating!
I don't consider myself to be particularly aggressive on the brakes and I'm always careful in doing warm up and cool down laps. I have DS2500's fitted.
Has anyone any opinions as to whether this is to be expected or can anyone offer suggestions (other than to stop doing track days!). Are the brakes not man enough for the job and should they be upgraded?
Thanks, Clive

Buckrogers

Read this:
http://www.stoptech.com/whitepapers/...otors_myth.htm

A long page, but well worth reading.

Buck

http://www.ebcbrakesdirect.com/

Soulgirl

What a superb link Buckrogers! I read that with interest as my discs look exactly like Fig4!

I might do as suggested and get a set of good "semi-metallic" pads. Can you suggest a manufacturer? I have the hispec 4 pot monster conversion calipers

ALi-B

iTrader: (1)

Check out his profile Soulgirl

Soulgirl

I did already, and was trying to act the blond bimbo in the hope of getting his undivided attention and perhaps a good discount, alas you have now blown my cover

Hoppy

Seen that link before. Interesting, but at least partially... bo11ox.

He seems to refer to two-piece race discs most of the time, and they are indeed hard to distort, but when he says he has "never seen a warped disc" he's contradicting himself. What he refers to as 'coning' is warping in my language.

Coning is the result of uneven expansion of a one-piece disc with integral bell, as fitted to virtually every new car. Take that car to, say, Donington and its OEM brakes will take a pasting they were never intended to endure. They will inevitably 'cone' and because of the mounting holes and unequal conduction of heat, they will cone unevenly.

I call that warping, and it certainly feels like warping when the steering wheel is shaking so violently it is hard to hold on.

Time to get two-piece discs (with separate alloy bell) which is what I got from those nice people at AP Racing. No more warping Alloy bells also help to keep the bearings cool, preventing pad knock-off which is another scary experience, ie pedal to the floor While I'm at it, alloy calipers also help keep things cool, helping to prevent fluid boiling and another cause of those unpleasant pedal to the floor moments.

He's right about pad deposits, though. It can feel like warping, occurs easily on high-performance road cars, and can be a bu99er to remove.

Richard.

Soulgirl

What would you suggest is the best approach for pad deposits Richard? Mine have definately succumbed to that problem so before I return them and ask for my money back what would you suggest? (bought 2nd hand apparently having done 3000 miles and told had awsome stopping power - only awsome thing is the bone shaking judder!)

Aztec Performance Ltd

iTrader: (234)

Agree with Richard.

I have some warped discs sat in the garage and there is no way that someone can say they arent warped. Had them checked with a dial-out gauge and they are indeed warped.

Bob

Hoppy

SG, if it's light pad deposits you can sometimes get them off by giving the brakes a good hammering. I've tried this before with success, but more recently it made the problem marginally worse. Binned the discs as they'd done their time. I don't think this is a solution for you though, from your description.

Another method is emery paper but I think that will be difficult, especially if the discs have surface grooves worn in to them, as they almost certainly will. Never tried this technique myself.

I've also never tried skimming, but that would certainly do the trick if pad deposits are your problem. Make sure you use a worshop that can work to very fine tolerances.

But if pad deposits are not the problem and it's warping, I would replace them. You could try skimming but warped discs have another trick up their sleeves - hot warping. That is to say, the discs cool flat and true, and it's only when you get some heat in them that the problem occurs.

Sorry if I sound negative, but I've gone through a fair few discs and chased this problem around at some considerable cost and hassle. Then went to AP and have never looked back

Richard.

PS If you do track days, you will almost certainly have to get serious with your brakes and go for AP or Godspeed (good value). Get the biggest two-piece discs you can. But it does depend on the circuit and while Donington is very hard on brakes (no real straights to cool off before the next big stop) at Snetterton there's only one big braking corner and that's after the longest straight in the UK. So I guess it depends. On the other hand, you could always drive like a girl (Sorry, couldn't resist!)

ALi-B

iTrader: (1)

oops! sorry - is it too late to delete my post?