View Single Post
      10-18-2012, 08:54 AM   #1
Brigadier General
jphughan's Avatar

Drives: '16 Cayman GT4
Join Date: Mar 2011
Location: Austin, TX

iTrader: (0)

Impressions/Pics of 265 or 275 square setup?

Well, thanks to helpful information on M3Post as well as some absolutely outstanding assistance from David@ApexRaceParts, I've got almost all of the information I need for my next mod: dedicated track wheels. At this point I'm just hoping people running what I'm considering can chime in with their subjective impressions and possibly even pics.

I'm going to go with the new APEX EC-7 wheel, running a square setup of either 18x9.5 ET22 with 265/35/18s or 18x10 ET25 with 275/35/18s, preferably the latter. This is going to start out as a dedicated track setup, but in case I decide to make this my full-time setup (since I'll also be buying Vorshlag adjustable camber plates), I'm also considering aesthetics a bit.

David@Apex tells me that the 10" wheels with 275s should only rub when using certain extreme performance/R-compound tires, and even then only slightly and briefly against the liner under very hard cornering, which I can live with; there's apparently no rubbing against the strut even at steering lock. However, most of the setups I've seen at the track have used 265s (maybe because it was easier since the rears were already that size?), so I'm curious if anyone here has experience with a square 275 setup, especially if they used to use 265 and especially if they're running camber in the -2.5 to -3 range as I'm planning. How does it handle? Does putting that much extra rubber up front negatively change the steering feel? Is it worth using 275 rather than 265? I'm mostly interested in track feel, but as I said may consider this as my road setup (with camber plates set for -1 to -1.5), so road impressions would also be appreciated. I know that both wheel sizes I'm considering will handle both tire sizes, but I want to pick the optimal pairing.

Also, does anyone have pics of a square 275/35/18 setup on 18x10 ET25 wheels (not necessarily the EC-7), ideally without spacers or any other appearance-altering suspension mods? From doing the math on the offsets I can tell that a square 10" ET25 setup will make the front wheels stick .89" farther out than my stock 220M setup and the rears stick out only 0.16" farther. It looks like everything will still (just) fit inside the fenders, but if anyone has pics of the setup I'm considering, I'd love to see a few. Hopefully the fronts don't stick out noticeably wider than the rears.

And lastly, since it seems 265/35/18 opens up more tire choices than 275/35/18, are there any issues running 265/35/18 in the rear even though OEM spec is 265/40/18? And if I wanted to be able to run either tire size on a given wheel size (even though I know I can't optimize for both at the same time), would it be better to run a 275/35/18 tire on a 9.5" wheel or a 265/35/18 tire on a 10" wheel? I'm thinking the latter since the ZCP rear wheel is 19x10 and BMW is running a 265/35 tire there, but I thought I'd ask.
'16 Cayman GT4 (delivery pics, comparison to E92 M3 write-up)

Gone but not forgotten:
'11.75 M3 E92 Le Mans | Black Nov w/ Alum | 6MT (owned 5/2011 - 11/2015)

Last edited by jphughan; 10-18-2012 at 12:02 PM.