Jay m A

iTrader: (2)

Hi

Was at Donnington on the 29th for a very wet trackday.

I was on my 4th session, even in the wet on Pirelli Pzeros my new godspeed 308 kit felt so much better than the old 2pots, I couldn't believe how much braking I had given the conditions and no ABS. However, I'm halfway through the day and I'm learning the track more and more, the braking distances are becoming shorter and shorter. Then I get vibration through the brake pedal when braking - at the same time I also hear a noise very similar to driving over rumble strips, and theres a slight vibration in the steering wheel. It got progessively worse through the next few corners, so I backed off and came in, letting everything cool down. I didn't want to risk it again, so I did'nt go back out.

About an hour later I drove back home, I did a few emergency stops on a quiet bit of road to judge how bad the vibration is...and its gone. Nothing! Its been fine since.

So did I warp my disks?
If so why? I assume in the dry I can work the brakes even harder, so its not as if I abused them that day?
If so, is it usually the fronts that warp? could it have been the rears? - I forgetfully put the handbrake on at the end of the 2nd session, but it didn't happen in the 3rd session and only started after 10mins of my 4th.

The godspeeds are 2 piece rotors and bells with mintex 1144's. On the rear I have OE disks and Pagid FR's, that need replacing soon.

Any ideas on what happened? All comments welcome

Thanks

Justin

sillysi

Justin,

I had a similar problem at Oulton a few weeks ago. I have standard disks but DS2500 pads on the front. Late in the afternoon I started getting vibration when braking from 80MPH. So I came in after a good warm down lap and the brakes were still smoking, the calipers had also turned white !! I went out later and it was still doing it but only when braking from high speed and this is the case when driving on the road, most of the time I do not notice it as I am driving at fairly low speeds. I had it in for a service a couple of days later and my dealer says the discs are cracked due to the non standard pads. This may be true but I am going to get a second opinion before replacing them.

Si.

Jay m A

iTrader: (2)

I gather it could also be wheel bearing related. Your thoughts anyone?

This is the first time the new front brakes have had a real workout (since I fitted them myself) so I guess I'd better re-torque everything....

Justin

Steve vRS

I'd be surpised if they were warped. It could also be an uneven build up of pad material on the discs. I've had this (335mm Godspeeds with M1144's) after a thrash but to get rid of it, go through a bedding in procedure, basically a few stops from 80mph to 30, letting the brakes cool between each stop.

If this doesn't help, speak to Ian Godney. As far as I know, two piece rotors should not warp and I think Ian guarentees his brakes against warping.

Steve

PS I was at Dono on Sunday in the DBM MY01

Jay m A

iTrader: (2)

Thanks for that Steve, the more I think about it the more I've convinced myself its wheel bearing related - I think I put more heat into the disks on a dry bedding in procedure!

I was in the silver WRX a few garages down - I think I introduced myself very early on in the day

Justin

Alas

Symptoms seem like warped discs. Reason maybe not appeared again is you have'nt given them the use to heat them up fully. I got this and was fine when driving normally but when pushing the casr on a longer journey (twisty roads) it appeared again. New pads & discs later everything was ok.
Alasdair