Brakes - the troubles continue

[h_____]

So I've had brake issues for a while. Long pedals, inconsistent feel thats certainly worried my last few trackdays. I think I've got those fixed so that the car finally stops properly. (although I've not tested on circuit).

My issue now is wear. I fitted new disks before Spa last year, and have since done a grand total of 4 trackdays, and guess what - I need new disks. I've got cracks through to the edges.

Its only the fronts, and I've cleaned the holes afterevery day at circuit and sometimes during. I know some of you get great wear out disks, so whats going wrong?

I've got new disks and pads (Pagid Yellows) being fitted now, with SRF fluid ready for France. I'm even fitting some extra ducting from the front to channel air towards the brakes.

The only thing I can think right now is that the bias is out (I use Pagid Yellows at the rear?) and maybe I'm putting too much on the front. Anyone think of anything else? Do you all get better wear than that?

Of course I went back to Porsche to ask for a goodwill gesture, its not fair to say they laughed at me, they kept a very straight face as I described the useage and the pads. Thankfully my Indy (RPM) are taking a much more helpful view.

 

[Melv]

There's a non adjustable bias valve in the system. Subject of a recall. Check it out...... Or revise your braking technique on track. Short and sharp. But I don't need to tell you that!!!

 

[carreraboy]

Seriously though, having done many hundreds of laps over the years at Spa in Minty, the discs were fine, I was using normal pads and not driving as fast and hard as you .... but I do recall Melv's words from the start ... seriously .... Was also driven for many laps by Sean Edwardes in Anger, with me as ballast he was spanking the big kettles, and not the most Pony Power, driven by Phil RS for a whole session instruction hard again, I noticed with the foregoing two peddlers they were using the brakes sparingly and sharp dabs ... pity I'm still crap[&o]

 

[oldtimer]

Hi h.....dont believe a word Des says...just remember what happened at Spa when you fell off the track !

Seriously , I've had some issues with brake disks cracking in spite of my careful driving style and recent installation of proper brake cooling ductwork.
I am told by former race team mechanics that the Achilles heel is the alloy brake hub , and this gets easily distorted which then has knock on effect of callipers dragging on the disk . The cure is to replace with the steel C2 hub assembly.

From memory the Spa incident was hub failure ?

I think Ian964 has fitted non Porsche either Performance Friction or Alcon disks , latter will work with Pagid RS29.

HTH

 

[Ian964]

I used to have Performance Friction discs on custom-made alloy bells, with PFC97 pads - this worked really well and the discs lasted a good 10-12 trackdays. However PFC changed their discs and stopped manufacturing in the size needed. Since then I've been using standard discs and RS29s all round, which don't seem to last anywhere near as long.

 

[MichM3]

stock discs all around with blue pagids here... very very happy with the brakes and wear!!

 

[rs phil]

I cracked 2 sets of fronts on mine shortly after buying it,short local circuit and ring trips
my cure was big reds 993 rs fronts and 964 turbo rears,i have only had to replace discs last week on front due to 2 cracks leading out to edge,rears were in alot longer than fronts and were same,so bias is correct... i think for tracking rs bigger front caliper is better,i was also running rs 29s etc,and then carbn lorraine rc6

 

[carreraboy]

Fallen off a few in my time but never Spa ..... anyway you should be counting all those massive Euro offers []

 

[Hacki]

The cure for me was yellow pagids all round and -more important- the change of braking technique (as Melv said).

No more probs ever since, bias not adjustable.


Hacki

P.S.: What discs did you use, original or aftermarket? (Originals normally last long)

 

[RSGulp]

I have a spare set of yellow Pagid RS29s which I'll bring with me to Clastres. Good 9/10mm pad thickness. Light use. [] Open to offers if anyone's interested.

 

[carreraboy]

They must be ten years old now ..... []

 

[RSGulp]

You can by them back if you like Des. They've tripled in value though. []

 

[h_____]

Right - crikey - lots of replies ....where to start....

yes Spa was hub failure, and incorrect fitments of replacement at circuit caused pad knock off and kind of killed the rest of the weekend.

Ian - interesting that you used aftermarket hubs and disks, if more come up I might pursue that route.

Melv - I guess I knew you would say learn how to brake - and maybe thats the answer. However, I dont think I'm too long on the brakes (some on here have passenger ed with me so can comment), that said, I wouldnt say I really understand how to stop the car yet.

Hacki - sorry should have mentioned - Standard disks based on advice from this forum.

RS Phil - I'm keen to keep the brakes standard, and resist upgrding if I can, but I cant stomach the costs at this rate.

Mich M3 - VERY interested that you get decent wear - can you be more specific on longevity? Pagid Blues! Humm, will have to check that out.

Finally the point about the bias valve may be a consideration, might get it checked out. I guess we'll have to wait and see. But I wont be a happy bunny if I'm sourcing more disks and pads after the next 4 days!!!

 

[clubsport]

I would have thought if the bias valve was out you would feel it in the handling under braking.

Having been privileged, to drive that car when Des owned it, I have driven it as quickly as I could (and we were not hanging about!) at Snett, Rockingham and Brunters.... There was no problem with the handling or brakes from a stopping or trail braking point of view, so if the brake bias is now out, it is a relatively new occurrence.

 

[carreraboy]

Spot on Clubbie and totally backs my Spa experiences as above and the Melv driving school, Hacki etc .....

Maybe H you got a dodgy set of discs or pads .. Minty never had a disc brake issue, or are you doing something different?

 

[h_____]

Bias valve still there, but it may not be working correctly, I do wonder if there is too much effort going to front......Get car back this PM, we'll see where we are. The brakes work OK, but I'm sure the front runs hot, which has caused the front disks to crack. Its really the wear rate that concerns me. I've had the car for over 2 years now, and we've changed/worked on a lot. Brakes, suspension, engine. Its nearly sorted - wear rate on the brakes and front dampers (hence watching MichM3s thread) are my to-do list at the moment.

Do agree it could be my braking style, but I'm not convinced thats enough.

We will find out for sure at Clastre.

 

[MichM3]

I don't track the RS very often, but the discs and Pagids blue are on the car for as long as I have it... since 2006, 10.000 miles.

Trackdays:

- Spa 4 times
- Dijon 2 times
- Folembray once

The front pads are now nearly at the end...discs don't suffer too much.

 

[Steve Brookes]

ORIGINAL: h_____

Bias valve still there, but it may not be working correctly, I do wonder if there is too much effort going to front......Get car back this PM, we'll see where we are. The brakes work OK, but I'm sure the front runs hot, which has caused the front disks to crack. Its really the wear rate that concerns me. I've had the car for over 2 years now, and we've changed/worked on a lot. Brakes, suspension, engine. Its nearly sorted - wear rate on the brakes and front dampers (hence watching MichM3s thread) are my to-do list at the moment.

Do agree it could be my braking style, but I'm not convinced thats enough.

We will find out for sure at Clastre.

I had a similar problem when I created too much bias by using Pagid greys on the front and standard pads on the rear. New front discs got toasted within 3 track days and I don't drive the car as quick as you (although on one of those days I loaned it to the Goose who drove it a bit harder []). So, when I replaced the front discs again, I fitted the same pads all round (Hawk blues). After 4 trackdays, the discs are holding up well (and they're smaller than yours). I think this partly due to restoring the right bias and that the Hawks are less harsh than the Pagid greys (although the Hawks produce a lot of nasty dust).

Nb. I'm not advocating the Hawks in particular, more that a less harsh pad than the Pagid yellow might be worth a try?...and on that note I've lost count of the times that Melv has recommended standard Porsche RS pads for your cars and they obviously work for him.

 

[carreraboy]

Don't forget the money back guarantee mate![]

 

[h_____]

You'd be lucky!!! [][] I'm way past that, I cant see me letting it go.

Melv was on Pagids last I looked, but gets great wear. Steve, good idea on balancing the rear with pads, I've got the same pagids on the rear for now. Seems we are mixed group on brake wear. I may have to resort to using the car less!

We are checking static brake bias tonight, see if that sheds any light.