HiWind

Hey Racers

hope the cold weather is keeping you all focused on RL
... gladly the snow hasn't reached us here at 34 degrees south

I noticed something today while prepping for the first race and need some insight please ... I know the GT3s are known for uneven pad wear but this experience is a bit more extreme

Problem:
Front Left side brake pads almost completely worn after replacing in Nov last year (ie 2 races and 2 prac sessions light use - 4 sessions)
... right side lasted 4 months ie 5 race days (18 sessions) ... we do flip pads between days to prevent the uneven wear bt this is uneven between left and right side of car, not just the pad

Pad: Pagid R29s, rotors Cup OEM

Possible causes:
1. Caliper binding - doesn't appear to be the case ie remove the pads and test the pistons feel and look for stickiness etc.. but none
2. Caliper flex or something else? 120 hrs on calipers .. turnings dark but not black or peeling paint etc...
3. pad locating pins - seem fine, also not sticky or preventing pad movements
4. I have been experimenting with "left foot braking" and may have been slightly on both pedals at exit ie still lightly on brake while getting into the accelerator ... ??
5. I can't feel the abs much (so much more subtle than on the 964 pedal) but I'm pretty sure I'm using it ... could I be over using it?

Questions:
1. should I order a setup of new pistons and seals just for good measure? I'm keen to try the stainless steel ones if they can help reduce heat and pad wear (?? - good idea? http://www.racingbrake.com/) .... for 996 cups: caliper rebuild kit
2. maybe just remove caliper and break down and review from the inside for issues - no leaks or other signs of problem ex the caliper discoloring.

Testing today: will drive session one with new pads (old rotors) and bed
sessions 2 - no left foot braking; feel re abs; look for 'pad smear' (instead of just pad dust) after session; session 3 repeat but some left foot braking ..

other suggestions?

thanks as ever,
Matt

Glen

Same track? If so, just swap pads from side to side. Assuming no significant pulling to more worn side under braking...

If you have pulling then rebuild them, cheap and easy. Don't need to replace the little inserts that just melt anyway btw...

rbahr

I would check/rebuild the calipers and test the pressure in the brake system.

Ray

HiWind

Yes we do swap them Glen and
yes I should have noted that it's the same track and haven't seen this issue in the last 3 years on that same track ...

But I think the rebuild kit looks solid - the Racing Brakes one linked above - anyone have experience with it?
The use stainless pistons instead of aluminium... Claim weight benefits and heat soak benefits ... Will look for alternatives too as OPC say they can't supply refresh kits for some reason (ie buy new caliper)

Also thanks Ray for the input

rbahr

IF you are looking for new pistons - get Ti - pretty sure that the RSR ran these and they do a good job with heat rejection and for what it matters they are light - gotta work on that unsprung weight

Ray

HiWind

interesting .. who stocks them for the cups? I've tried google and only find the 'backing plates'

https://hardbrakes.com/index.php?mai...products_id=57

rbahr

Perhaps I spoke to soon.

The pistons for the Cup and RSR cars are part of a refresh kit, and the manuals don't indicate the material used. Stoptech make some for their brakes - but they look a lot like the ceramic inserts that are OEM on GT3's and other cars. A good machine shop could do something like that for you.

I have seen them on Nascar calipers and others. I have also used the shims on my own non-Porsche cars ...

Ray

HiWind

how did you find the ti shims/shields worked?
... that idea seems a bit 'thin' to me, but I guess there's no substitute for real world tests

rbahr

Not worth the aggravation

I WOULD consider Ti pistons, but still need to move air...

If you have the chance, check out the RSR brake cooling - pretty impressive

Ray

HiWind

agreed - ducting is the key determinant - cheers Ray