I get what's involved with installing/removing these CL wheels and even the conversion to five lug, but what I never see is anything about aftermarket options and their specs.

Besides members or sites listing wheels for "Porsche WB center lock", is there another spec that these wheels go by? How do you know if a CL wheel of another manufacturer (O.Z., ATS, BBS, etc.) fits the GTS? I see some wheels online that claim they fit a wide array of p-car applications, but when looking at the flange shape/size/surface (flat vs banked ~45 degrees) I can never be sure.

Are there specs or measurements for CL wheels like there are for traditional wheels (e.g. 5x130). Every listing I see for CL wheels is very ambiguous about the actually mounting.

 

For what precisely are you looking? A 5x130 indicates a 5 bolt pattern with a diameter of 130 mm. I guess a centerlock equivalent would be the diameter and depth of the center hole. Of course, there is the offset, too.

 

Precisely my point. When centerlock wheels are listed for sale, there is never a mention of the center hole specs.

Along those lines, what are the specs of the hole in the OEM RS Spyder wheels for that matter? Does anyone even know? Widths and offsets aren't the issue but the actual hole/flange size. It seems the only thing we can go off is that the seller states "for Porsche." But how can we verify it will mount up to the GTS?

 

See https://rennlist.com/forums/porsche-...rque-spec.html

 

Thanks for the link but that covers the size of the actual lug nut, not the flange/hole spec.

Let's keep this as simple as possible, will these fit the 997 GTS?: http://www.ebay.com/itm/ATS-Centerlo...53.m1438.l9372

Let's not get hung up on widths and offsets because those are subjective (and I've already determined that those are too low of offset for my GTS), but how would you personally determine/validate whether they'd fit the GTS (other than the seller listing "Porsche" and "997" in the title?)

Does that make more sense? There are many centerlock wheels for sale online, how do you determine if they will fit the GTS? Is there a universal unit of measurement to compare against/validate (e.g. 5x114mm for stud systems)?

Hopefully that's more clear.

 

Sorry, can't help you. I know just enough to be dangerous. But, offhand, i would be especially leery of any wheel that purports to fit 993/996/997. Plus these are 18" wheels while the GTS have 19", so, more translation of specs needed.

 

No, those won't fit a stock 997 GTS or any other 997 that uses the street centerlock system (GT3, RS, Turbo, etc). Those are for motorsports centerlocking systems which are not the same as ours. Typically when you see 18" centerlock wheels that are "centerlock" for Porsche they're for the 996/997 cup cars which use the motorsports centerlock system.

I've not found an exact spec for which centerlocks fit our cars, but since no other manufacturer really pushes centerlocks, most people just talk about either the motorsports spec or the street spec. I'm pretty sure all street spec centerlock wheels are cross compatible at the lug, but obviously the offsets will have to be checked for clearance. I've seen people mount 991 centerlocks to 997's, and vice versa (not that I'd recommend it). The smallest Porsche centerlock for our cars are 19". The way you can kind of tell is by looking at the center of the wheel where it should have a concave shape where the lug fits over it. The ones you've linked have a flat face which is what the motorsports centerlocks mate to.

 

scorcherjf is right plus those offsets are not ideal for 997 fitment unless you are looking for stanced/weird fitments

 

Thank you, that's the exact answer I was looking for in regards to differences in mating services (flat vs banked) and locking system. So my suspicion is correct, there is no real "standard of measurement" that us GTS guys can use to determine whether a set of CLs will fit or not. Bummer...