DaveBeck

iTrader: (12)

Did a track day yesterday, ive got 325mm on front and standard 290 rears. rears were only just broke in and fronts had done 4000 max.
they are fine but once they got 6 laps in/hot,they started juddering/ shaking through the car. no loss of brakes though., they were working superbly.

wierd thing is that the judder almost disapeared at the end.

Any ideas what i should check now, i intitially thought warped discs but it went away throughout the day.

using ds2500 on front and green stuff rear and 5.1 fluid

dynamix

iTrader: (3)

DS2500's leave uneven pad deposits if they get (too) hot and will screw the discs.

rickya

iTrader: (18)

Plus they leave sh&tloads of brake dust everywhere!!

D1CCY

Yes this is pad deposits which wear off with less agressive braking hence the problem goes away (can happen with most pads although DS2500 have lower temperature limits than some alternatives). Root cause is overheating/braking too hard.

Two things to do:

1. Improve ventilation to the brakes. I have an 03STi and I leave off the false fog light covers and cut a hole in the plastic wheel arch to get cold air behind the front wheels, works a treat on track.

2. Don't brake so hard, I'm just as guilty on this and my instructor tells me off for it. If you brake a little earlier and gentler it is possible to get the car more settled and carry more corner speed. Also if you screw up your braking point you have room to adjust.

bren@apex

iTrader: (20)

The Ferodo DS2500s are a great pad for the money and I personally have never had an issue with vibration with them on road or on track. However if you are having problems then Id suggest the Performance Friction 01s, an absolutely amazing pad.

Neanderthal

iTrader: (6)

I've had smoke come from my DS2500's after a short (as in 3-4min) blast down my favourite B-Road. At the end of this road, I have to stop at a T Junction. Imagine my surprise when I noticed smoke coming from the front wheels!. They seem to be ok though, once I was moving again, avoided braking and gently run it home for the last 10 mins of the journey.
However, considering the 'track' use these pads are meant to be good for, I won't be buying them again.

dynamix

iTrader: (3)

They are at best 'fast road' pads - not track pads.

Do a search on here for 'brake judder' or 'warped discs' and each time the user will have been using DS2500's - it isnt a co-incidence (nor is it warped discs)

bren@apex

iTrader: (20)

We have experience of DS3000s causing vibration. When they get too hot and run out of their ideal operating range then they leave deposits on the rotor face causing vibration.

Ive cained DS2500s to death on the road and track, never had the same experience :no: They only problem I get with DS2500s if driven really hard on track is that they get wooden and lose bite. Never actually got to the point of fade with them though.

Theyre fine for the occasional track day user. Performance Subaru ran DS2500s front and rear in Time Attack this year. They came second overall and and running on the same pads now that they started on at the beginning of the year.

I can only report with my personal experiences and those of people I have direct contact with and in my experience I personally have never had vibration issues with DS2500s nor do I know directly of anyone whos reported vibration issues back to us that specifically relate to DS2500s.

And we have lots of experience, both direct and indirect. We have sold many many thousands of sets of DS2500s. A lot of these were for the S14, a car running identical calipers and pads to some of the GC8s. As a company we have close ties with a large number of track and competition cars, with direct or indirect control over dozens of vehicles over the years.

Im not arguing black is white, just reporting what I know.

You should expect to get the pads smoking, thats what happens the first time they get a proper caining. It just means theyre now properly bedded in

DaveBeck

iTrader: (12)

Cheers for input lads, appreciated.

As said the problem got less and less on the track, but was still there a little at the end. the pads had seen 3k miles but maybe werent bed in hard enough.
the car is fine now which leads me to believe its deposits.

maybe try another set of pads at the next track day to make certain its not discs at high temp.

liking the idea of the vents and ive seen myself some fog covers perfect for the job

will dig this back up and report after my next track day

bren@apex

iTrader: (20)

You can also glaze the DS2500s if you get them too hot for too long. If you get to this point then braking performance goes out of the window. We have only experienced this once and just used a belt sander to get back down to fresh material.

DaveBeck

iTrader: (12)

never lost any performance on track Bren.

or are you just saying this as a general point ?

dynamix

iTrader: (3)

Dave - speak to Alyn at ASP about PF Z rated pads. They are a MUCH better pad and you will not have any issues like this with them.

bren@apex

iTrader: (20)

Im just saying that the worst Ive experienced with DS2500s is a wooden feeling when they get really abused as the pad surface starts to glaze.

banny sti

iTrader: (68)

Only had my PF stuff on for a couple of days but it is a brilliant upgrade for the brembo calipers, so much more bite and braking power

Banny