guykoken

I note that the standard (steel) 997GT3 rear discs are 350mm diameter, which is the same diameter as the 996GT3 rear ceramic discs.

Would one of you kind souls who is better connected to PCNA than I am kindly determine if the 997 GT3 rear steels are in thickness and bolt pattern identical to the 996 GT3 rear PCCBs. If they are, than the walking wounded among us can do a straight swap on the rears.

Please post your answers at this thread.

Many Thanks.
Richard Bain.

Sloth

That would be great. Hopefully the necessary dimensions are the same.

911 silverback

I just phoned Porsche GB with your question, they will get back to me tomorrow if that helps. I run the pccbs too, with the street pads.( no probs so far 8500 miles) I just started doing track days (2) and have realised i have totally the wrong pads for this use.
The last one i done at the weekend at the Bedford Autodrome, got to the point where it felt almost dangerous as the car just wouldnt stop, talk about fade!
So for the time being im going to replace the pads with Pagid yellow 19s or 29s, what do you guys recommend?
I have this in mind as a temporary measure because i have another track day booked in next week, but for the long term i realise the track will kill the pccbs so i need to convert to steels.
Sorry if this is a dumb question but why cant you use the 996 GT3 steels? Is it not just a matter of buying 4 new steels from Porsche?.
Thanks in advance
...rob

Sloth

The front steel rotors are a direct swap since they are both 350mm. However, the rear steel rotors are smaller (330mm) and require a different rear caliper during the conversion. Since the steel rear rotors on the 997 GT3 are 350mm the hope is they will be a direct swap for the rear ceramic rotor on our 996GT3's.

Bob Rouleau

Silverback - the RS 19 and 29 work very well on the PCCB and help preserve their life.

I converted my PCCB to GT3 steel. The fronts are a direct bolt on. The rears are 330 MM and require a different caliper. These are available in yellow from Porsche - GT2 Steel Brake Kit. As of now, Porsche does not have a 350 mm rear steel rotor. If the 997 GT3 rotors fits, then it would save purchasing a new calipeer for the smaller diameter 996 GT6 rear rotors.

Rgds,

BobbyC

Bob, would you recommend RS-19 also for the Gen2 PCCB's on a TT? Thanks...

911 silverback

Thanks guys i will follow up my enquiry direct to AG tommorow if GB dont get back to me. I guess you fellas have already been over this ground but it seems strange Porsche couldnt have done this a long time ago for pccb owner cars, im sure it would have saved a lot of agro!
Guykoken what happend with your action regarding PCCBs did you get anything resolved or is this on going?
Bob i see you have converted to GT3 steel do you think they offer best VFM with so many other after market options available?
Cheers
...rob

911 silverback

BobbyC i spoke to the main importer of Pagid to the UK today he knew all about gen 1 and 2 PCCBs he recommended to me to use the RS29s.
Apparantly they are the newer better version of the RS 19s, do you guys agree with this??
cheers
...rob

DanH

Rob - RS29s are what the RS boys are using in the UK. They don't seem popular so much in the US from what I read hear although not sure why.

Porsche OEM drilled disks have very poor life expectancy on track. JZMachtech or Parr Motorsport can supply you with race spec alcon/brembo disks although you need to consider how noisy they are - I know JZM can now supply a quieter option. RS29s aren't exactly quiet either.

Replacing the rears is the expensive bit with these new alcon/brembo disks due to the size. Given they wear a lot less than the fronts, if the 997 ones fit that would be a very good cost saving.

For reference a complete swap of pads and move to floating disks with JZM is in the order of 3k GBP. Part of that is the high cost of RS29s, but the rears disks setup is also expensive. It should be cost effective over a series of trackdays however, but I'm personally balking at the cost!

Bob Rouleau

BobbyC - I cannot say. No experience with Gen II PCCB but I can't imagine that the Pagids would work any differently. The RS 29 pad is similar to the 19 with slightly more initial bite. I had some and observed that they are thinner than the RS-19s - perhaps this was a production tolerance thing.. I don't know. They were about 2 mm thinner - this could be an advantage though. When fitting new RS-19 pads to new rotors it is almost impossible to get them to drop into the caliper. based on what I saw of the 29s this would not be a problem.

With respect to the GT3 rotors, I prefer them. I buy replacements from Gert Carnewal in Belgium, he supplies the Motorsports version and landed in Canada they cost $400 Canadian dollars.

Several of my pals have gone to the floating caliper slotted rotors mentioned in this thread. The results have been less than stellar. The clacking noise is annoying and I would not put up with it. The hats wear (bolt holes get enlarged for some reason) so the idea of replacing rotors only is not as good an option as it might sound. You lose the hand brake since the rear hats do not incorporate the drum brake found on the GT2/GT3 hats. Lastly both guys who fitted them to their GT3 are complaining about a mushy pedal. I don't know why. I am sticking with the Motorsports rotors from Porsche.

Best,

NJ-GT

The front and rear hubs (wheel carriers or uprights) on the new 997 GT3 are a carry over from the 996 GT3 RS (hollow hubs). I'm not positive, but my bet is the 350mm rear disk will be a direct swap, for the cars with PCCB. The 350mm rotors at the rear help with brake bias, on a car that on street setup is heavily front brakes biased.

I have quite a few track days with PCCB and RS19, but when my pyrometer fails to provide a reading (rotors too hot), life expectancy is being reduced. Brake rotors are wear items, regardless of the material used for them.

With the recent truth revealed about PCCB lasting just a bit longer than steel on the 2005 Porsche SuperCup, and the fact that the 2006 997 GT3 Cup is coming with steel brakes, I think Porsche has realized the fate of PCCB on Motorsports: The juice isn't worth the squeeze.

No matter what size PCCB Porsche makes, they will wear out, and they will be expensive to replace. This is an expensive technology. They should invest on lightweight materials for wheels (PCCW ?), and make lighter slotted steel rotors.

viperbob

Hmm, some good ideas. I'll get a 997 GT3 rear rotor coming from Porsche Motorsports (again the same theory would hold that the Cupcar rotor will be less than 1/2 of the street car cost). I'll check first hand if it is a replacement option.

Nordschleife

slotted rotors can be very hard on pads, light iron rotors have less braking capacity, shorter working lives and promote fade faster than heavy iron rotors.
My brake guy has, however, optimised the aero profiles of the internal vanes in the rotors to improve performance.

Finding a way of attaching 4 inch diameter ducting from an air inlet to the brake hubs would be a great help in terms of longevity and countering fade.

R+C


R+C

Bob Rouleau

Viperbob - well done! It would be a nice solution and an interesting upgrade for GT3s with steel brakes.

Best,

TM

Hi,

Err ... aren't the pads used on the 350mm and on the 330mm disc the same size? If this proofs true there won't be any change in brake bias.

Cheers