I know there are a handful of threads of different track setups for any years that have the 20" rear wheels. I have a 2012 with the SVTPP and tossed around the relocation of the rear sway bar to fit 15's or squeezing in Nitto 305s, M/T's or other drag radial. I haven't seen much on the setup I finally chose, so I wanted to throw out what I found. I went with the Hoosier 28x10-17 slicks ($220 from Summit - link below) mounted on some 17x9 replica wheels from American Muscle ($110/each - link and specs below).
The 28" Hoosiers are only slightly smaller than the stock tires when inflated. Theoretically, the diameter difference should be 0.1", although I did find it to be slightly more exaggerated in real life. The Hoosiers were at 15 psi, and I saw about 1/4" difference from the stock Goodyear ties at 35 psi.. I obviously I not concerned about the speedo difference for a track setup, and I never had any difficulty with the traction system registering problems.
There is very little overhang, as you can see here:
The clearance from the shocks and everything else in the wheel well is also more than acceptable.
As far as performance, I unfortunately only got two runs in this week. Both were disappointing, and I still have a lot to learn about launching this car with the slicks. I can say, though, that traction was perfect without a single slip at any point. Now, I just need to figure out the best launch RPM and amount of feathering/clutch dropping. Any experience from others here would really be appreciated!
Best run: 2.01 60': 12.4 @ 116
Wheels: 17 x 9 with a +30 mm offset (6.18" backspace)
Some other pics of the setup:
Thanks for looking! I have really gotten a lot out of other's posts on this site and and happy to finally have something to add myself!