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Discussion Starter #1
This is what happens....

At the end of the trackday on Monday the brakes started to judder very badly and when I drove home they were banging like mad. This is what I found when I looked at them:-

 

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Discussion Starter #3
Bedford Autodrome GT circuit.....its quite hard on the brakes with 3 hairpins following straights at the top of 4th gear.

No question though, it needs better brakes!
 

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ouch that looks nasty....

Not sure if it is too late, but there was a 2nd GB for the brembodge setup running over on RT; not sure if that would be an upgrade or not though.
 

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You need to change the pad material you are using or think about your braking technique ;-))

You are having to hold the brakes on too long which is why the disc temp is going so high the material is expanding and fractures.
 

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Front wheels steer, rear wheels drive.
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yeah mine couldnt take the pressure when i went f.i but sheeesh thats bad.
 

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This is nothing to do how brakes are used. If everything is as it should be this wont happen. But let us first know which brand of pads are used and I want to know how brakes are serviced before I say what I think.

Remember that I have taken front disks of my VVC up to red hot during every stage I have driven. Still using orginal disks.
 

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Discussion Starter #8
I changed the pads the last time I went to Bedford in April, but only did a few laps on them and they were still more or less unworn. They are Performance Friction (its the fist time I have used them but they came highly recommended). There was no fade at all, but they didn't seem to bite as well as the original DS2500s that I replaced, so (to your point Matt) I couldn't brake as late as I usually do.

The other rotor is also showing signs of cracking too, but it looks more like the surface cracking that is much more common.

A 300mm disk should be able to handle the power/weight of the car, but to be honest I'd rather have overspecced brakes that you know will last a while without having to be changed after every event. Remember this is a track day car, not a competition car, so I'm not chasing down the lightest set up, I just want it to be much better than standard without the need for constant parts replacement.

The other problem with the set-up is that the rears are standard size, so all the extra braking effort it concentrated at the front. I'll be uprating the rears when I re-do the fronts.
 

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Front wheels steer, rear wheels drive.
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intersting, my brakes were ok when running ds 3000 pads but as soon as i swapped to the performance friction jobbies they went down hill, 2-3 fast laps and the discs were warping and causing judder.
The supplied discs with the wildwwod kit are quite cheap and basic but you can get better quality wilwood discs if you look on the net, and in the same size.
If i ever built another car i would go all out on the brakes on a big reyland kit, same as you say, you might gain a few pounds but the confidence you gain from knowing your brakes would probably outweigh that anyway.
 

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How old were the discs?
Maybe they were already on the thin side which would have caused them to get hot.
My ap 325mm discs cracked the same and warped when they got too thin.
Rear brakes don't really need to do much at all.
I am guessing yours is only around 1100kg?
The tomcats only run std rear brakes without issues
 

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Discussion Starter #11
The disks were nearly new - no signs of wear at all really.....
 

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do you have brake cooling ducts? if not could make a differance

Did you bed them in as per wilwood instructions, my ap ones the bedding in proceedure was differant to I would have expected or apparently they can distort or crack from new.
 

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I had the same thing happen to me on the old scooby, after using some Black Diamond drilled + grooved discs (i wont them in a raffle lol)

They both fractured at the exact same time, which i could never work out, as they went on the road on the way to my mates car wash to pay him a visit.

Lucky for me i was quite close to him, and managed the rest of the journey by using the handbrake LOL

Directly opposite his car wash is a motorfactors, so we removed the ****e drilled/grooved discs and threw them in his skip.
 

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The disks were nearly new - no signs of wear at all really.....
Have you changed the disc, because if they where the same set that was on when i sold the car, i did a good hand full of trackdays with them, i wouldnt call the nearly new!

Sie
 

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Discussion Starter #15
Have you changed the disc, because if they where the same set that was on when i sold the car, i did a good hand full of trackdays with them, i wouldnt call the nearly new!

Sie
Hi Sie, no I didnt change the disk, they were only nearly new in that there is no signs of wear - they are the same thickness as new. I think it was the change to Performance Friction pads that killed the disk. They were showing signs of pick-up after the first day I did with them and they just got worse. I suppose I should have sanded the disks after I'd changed the pads to get rid of the old pad deposit, but I was too lazy.

Got a set of 330mm APs on order from Martin at Reyland now and I might put the Wilwoods on the back with a little handbrake caliper to keep it legal.
 
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