edfishjr

What may be the case is this: the "same" wheel on a Carrera comes at the width stated in the order guide. When you order that "same style" wheel for a Cayman, it is not as wide, with a skinnier tire as well.

So far, I haven't found anyone who got an 11" or 11.5" option wheel on a 2009+ Cayman(S) from Porsche. 10" is all I've found. I'd love to have proof of someone who did.

edfishjr

Went by my Porsche dealer to talk option wheels on Caymans & Boxsters. They had a 2006 CS in for service that they had sold. They printed out the option sheet and verified that it had been ordered with the XRR Carrera Sport 19" (10-spoke) option wheels which were on it, described in the order guides for many years as 8.5" and 11.5" wide.

They were marked as 8.5 front and 10 rear. The service manager pulled out a pair of calipers and confirmed the sizes.

sjfehr

That makes things complicated. How are we supposed to document and prove 10" rears are OEM when Porsche's documentation says 11.5"?

PedalFaster

If the order guide says that 11.5" wheels were available, then you have a reasonable case for arguing that they're legal even if no car was ever delivered in that configuration. There's precedent -- the ES Toyota MR2s to have had both ABS and sunroof delete, a combination that was technically orderable but apparently never delivered, and the CS Mazda MX-5 MS-R was likewise supposedly orderable but was never delivered from the factory.

You might want to write a letter to the SAC / SEB for clarification.

Edit: Just realized that I answered the opposite of the question you were asking. I'd put the information from edfishjr's post above into a letter to the SAC / SEB, and include links to any other authoritative refences you can find stating that the actual rear wheel width was 10". It's likely within the SAC / SEB's ability to independently do the same thing edfishjr did, at which point I'd expect a clarification from them.

sjfehr

Honestly, I don't care whether it's 10" or 11.5", just so long as I buy the right wheel! Will an 11.5" wheel even fit? That might be why 10" were fitted.

edfishjr

... and I took pictures, which includes the offsets as embossed on the wheels as 55 front and 42 rear.

PedalFaster

Well, based on what edfishjr wrote above, neither wheel width is 100% obviously legal. If you're serious about running that car, I'd write a letter asking for clarification either way.

edfishjr

I suspect your are right about that. I have seen Caymans with 11" aftermarket rear wheels, but I don't know what offset they might have had to use to get them to fit.

sjfehr

Shame Porsche had to make it this difficult.

For another Q: How competitive will 987.2 be against 981 in A Street? 981 has slightly more horsepower and optional "sport" suspension that is 20mm lower than stock and 10mm lower than PASM that I presume is also stiffer than PASM but can't confirm. Plus torque vectoring. PDK gearing is literally identical but with final drive ratio adjusted for the higher 7800rpm redline- top end speeds work out within 1mph. I'm thinking 981 may be a few tenths faster and more competitive with CR and C5, but I don't think it will be that huge a difference. (Yeah, I made the mistake of visiting Porsche's configurator... please stop me from doing something stupid I can't afford!)

Did Porsche loosen up the nannies on 981 or tighten them? I couldn't tell on the 981S I drive; Porsche dealer wouldn't let me do powerslides in their back lot to test it.

knfeparty

I recently noticed that all of the corvettes are moving down a class: super stock Vette's like the c5z06 will be in a street, even the gran sport I think. The zr1 will be in super street. Not surprisingly Porsches are all staying put. Sucks to compete against the favorite.

sjfehr

Sam Strano, Mike Johnson, Courtney Cormier and Jim Newman did some tire tests on Newman's FRC a few weeks ago and found the FRC was 2 seconds slower on a roughly 45 second course on Rivals vs A6. Extrapolate out, and that's a massive performance hit to the C5 on street tires. In my own tests in my BS 986S, I worked out about 2 seconds difference between Z1 Star Specs and Kumho V710s; I figured probably 2 seconds (give or take) between ZIIs and A6s, which is only about half the hit the vette took.

Now, Newman's FRC was optimized for A6s and the Rivals were sticker so there may be some performance to be gained back, but I really do think it will end up being course dependent with Caymans very competitive vs the vettes on most courses. Time will tell, I suppose. There may be more shuffling between classes as more is known. I daresay Porsches will never be classed as "the car to have" but so long as I'm within a few tenths of that car on avereage, I'm happy.

PedalFaster

Take a look at the Super Stock results from this year's national championships. When you're done, take a look at the Super Stock results from last year's national championships, then report back to the class.

sjfehr

Ah, touché! Of course, we all know the GT3 is tolerated because it's one of several top cars in SS; if it becomes a runaway favorite in S Street, it would be bumped to SSP with the rest of the supercars. Honestly, I fear for the future of Lotus Elise in street class, simply because it's so damned fast on street tires and has nowhere higher to get bumped to.

Also interesting from a street tire perspective is how ST* did this year and how the tire limitations impact different cars so differently. Top times for STR & STC at nationals this week:

STC 133.575 (God's chariot on cheater Toyos)
STR 133.576 (350Z on Hankooks)

abqautoxer

And no one has run the GT3 to have in SS yet though from what I heard, someone will next year.

knfeparty

I worked the course when these guys ran. All of them insane fast. The east course was designed by Sam Strano, who was of course competing in SS in a Vette. Oddly enough the viper and a gt3 took the top 2 spots on that course. In the grid, the gt3 guys were swapping tires between every run!

Take a look at the A stock results and you'll see how poorly the 996 does against the c5 Vettes...on old BFG R1s....with my crappy driving. If I go again next year, I am bringing a couple sets of new A6s. I brought a set of take offs home to try out. 255 fronts and 315 rears like the 996 gt3 guys were running.