montoya

I have a set of cup car discs for my .2 GT3. My tech says they don't quite fit right. Anyone have experience with these? Is my tech being too fussy or do I need to use different bolts or spacers?

911rox

The problem is the holes where the drive pins fit... The cup pins are about 1mm thicker and therefore your drive pins won't work... As far as rotor offsets are concerned, there is no problem as I recall...

I got caught out when PFC sent me the cup rotors instead of the .2 rotors. They did fit but the drive pins were a no go. They fixed the issue by sending out the .2 hats....

montoya

OK, that's the issue but I don't think that you can change the hats on the discs.

I bought these here with the claim they were a direct replacement. It's very frustrating. The seller claimed to be using them on his RS.

Maybe they only work in Florida...

911rox

Montaya, they were a direct replacement for the 997.1 carbons which were also a 380mm disk... You are correct, a hat change is not possible with the OEM cup rotors and the pins will float within the holes. The seller has accidentally misled you...

911rox

Forgot to mention, this was the first option I investigated before going the PFC option... They are certainly far more resistant to cracking then the street rotors...

montoya

Well, the seller claimed to be using them on his .2 RS. I wonder if there is something that can be done?

911rox

The diameter difference in the drive pin/stud holes was exactly 1mm... Unless he used some sort of rings to take up the slack, I don't see how. The guy who did my install was head of motorsport at the dealership and he strongly recommended against using the PFCs with cup hats as it would allow movement which could shear the pins... Might be best to just ask him about how he had them installed to see if he was using them with pins loose which I wouldn't recommend...

Protocav

After the lugs (or in this case centerlock nut) are tightened, there will be no shear force left as the clamping force should be greater. I suppose it's possible to shear the pins but that would assume that the wheel is free to slide/rotate on the face of the rotor hat and I think that is unlikely.

montoya

I know some people have used them. We need to hear from them. Meanwhile the vendor is RPW, I will contact Eduardo.

paver

Maybe they work. With the history of problems with street centerlocks I was not willing to risk it though. He should tell people up front they are not an exact replacement.

Alan C.

Since the pins are a maintenance item can the proper pin for the cup rotor be installed?

Izzone

Cup pins cannot be installed

I saw these on Eddie car when he ran them..

Back a few years ago when Peter and I were testing hats for PFC, we used the cup hats with oem centerlock hubs. There was never a problem. That being said they did develop a proper hat

I agree the nubs on an oem centerlock are for alignment, clamping force holds the disk

Alan C.

Thanks for the clarification.

montoya

Yes, this is what Eddie just told me on the phone- that the first PFC disc was per cup car specs and people used it and that the cup car disc can be used just need to center the pins using the old disc.

911rox

Effectively, under heavy braking and acceleration, the wheels can move that 1mm back/forth until the pins come to a stop against the other side of the hole in the hats... Whilst it has been done, if you see the flimsy design of those street car drive pins, you'll understand why it's not a great idea and why even PFC made a hat specific to the application... My further $0.02..