daveo4porsche

just fyi my personal assessment is that the 997.2 center locks may not be the best choice for a track heavy car. And given that I take my personal safety very seriously I have taken it upon myself to swap out the center locks for the Cup Car center locks. This conversion is now mostly complete and we're wrapping up some details.

I will post pictures when I can - people wishing to see this conversion in person are encouraged to attend GGR Thunderhill on July 14 & 15 or HOD Miller on July 21 and 22, and more recently the high desert invitational at Reno on Nov 2-4…

I will of course report and update this thread on my thoughts and impressions of this conversation.

Carrera GT

It certainly would be nice to be able to rattle the wheels on and off with an air tool, and tie down nuts would be very handy.

After two years on the track in a 3.8 RS, I don't think the Centerlocks are trouble, it's a well worn topic. But there are two recent incidents (of catastrophic failure) which will force Porsche's hand to address the "usability" aspects of the street centerlock design.

As with the coolant fittings, we can only hope they sort it out before they kill someone.

For a GT3 that's mostly track-oriented, I wonder what the intended service life of the motorsports hub and centerlock should be.

deputydog95

Is there actually a battery powered impact drive that can produce enough torque? I think I would rather carry a 4 ft wrench than a giant compressor or air tank.

ir_fuel

The best of luck with your cup car center locks. Just remember that those nuts and hubs also need replacing from time to time or things can go wrong.

Just wondering, why not opt for the RSR/Carrera GT system?

FLA997

He is probably staying away from the CGT/RSR version because the wheel to hub mating surfaces are completely different for that system, and he wouldn't have many (if any) wheel options for his street GT3.

Note the conical hub that is unique to that setup - street wheels wont work.

mooty

yes
I used it personally on cup car. snap on 18v

FLA997

Mooty - this one?

http://buy1.snapon.com/catalog/item....store&tool=all

911rox

Also Milwawkee v28....

mooty

yes.
and in fact, i have two more brand new ones i like to sell.
dont ask... i ended up with 4 of them.

daveo4porsche

I know of 3 incidents and have heard of more. It's my assertion that for the limited number of cars on track with them and only being on the market for 3'ish years - even 3 failures is statistically significant for a low volume production car like a GT3. Also porsche's attitude that unless they are properly maintained (i.e. you haven't followed their easy 2700 step process) catastrophic failure is just fine with us doesn't sit well with me. It's hard to find similar levels of failures for other forms of wheel attachments.

Also porsche motorsport publishes a "useful" life guidance for the cup car center locks - but I know of no such guidance for the street center locks.

I went with the cup center locks due to the availability of "spare/loaner" wheels in the group of people I run with - I have my own sets (well I do now) but others in the group also have cup cars and will be making similar modifications to their GT3's - so I will have a pool of wheels to help save a track weekend. YMMV on this sort of thing.

CRex

mdrums

Interesting that you choose cup car center locks but I read where you have some friends with extra cup car wheels.

Would the cost to 5 lug be less expensive in parts and actually many more choices in 5 lug wheels?

Do stock rotors fit or now don't you have to use even more expensive rotors for cup car hubs?

How are cup car center locks for street use?

deputydog95

I think I would have done 5 lug instead of another type of center locks. You could always buy a second set of 5 lug wheels.

tcsracing1

So, can you still use your stock center lock wheels with the Cup center lock system?

mdrums

My understanding is that the conical surface shape and size of street center locks and race center locks is totally different.