Issues changing rotors for first time since I've owned this car which is a 2004 GT3 built into track car with Porsche Motorsport Cup Car Centerlocks.

Ordered these Giro Disc rotors from Craig at Rennstore and didn't even think to ask if there was any difference in fitment of center hats for the Cup Car centerlock hubs. Car had stock rotors so never occurred to me that there may be a difference.

Has anyone run across this? Car still has "Stock Rotors" that I am replacing and looks like they were reamed out to fit.

Suggestions? What is best way to machine/ream out Aluminum hats which I'm assuming is what needs to be done? Will call Craig @ Rennstore tomorrow to check and see if I could/should have ordered specifically for centerlock but have never heard there was a difference?

Thanks for any input ahead of time as I was hoping to get these swapped out this weekend and was bummed to see they didn't just fit right up.
Can also ask Dan @ Speed Gallery tomorrow as well who built this originally and swapped to center locks.


Thanks, Eric

 

Those are Street GT3 Rotors with the smaller drive pin/lug holes.
We have the Cup ones in stock.

 

just use step drill bit and drill bigger hole.

I found out same think when time come to change front rotors on centerlock hub for a first time.

 

^ drill press

 

21/32 Tapered reamer works best

 

Thanks Dan