djm68

Hello,

I am researching this seasons tire choice. As I run in an organization that follows SCCA Solo rules, I will fall under the new "Super Street" class, formally "Super Stock" when R-Comps where allowed. This year tires choice will be limited to tires with a TW rating of 200 or higher. I have my selection narrowed down to either the Dunlop Direzza ZII or the BFG g-Force Rivals. My intended use: a track day or two, a few autox events, but mostly I run in hillclimb series: essentially two mile, up hill, time trials.

My current setup:

OZ Alleggerita HLT
8.5 x 18" - 53mm
10 x 18" - 40mm

Nitto NT01
245/35/18 F
275/35/18 R


The BFG's are supposedly the hot ticket in tw200 range, but as they are new, they are unproven. If I were to go with the BFG's I'd be limited in my size choices to:

245/40/18 F
275/35/18 R

Where as with the Direzza ZII, I have a much broader size selection:

245/35/18 F
255/35/18 F
265/35/18 R...or F?
275/35/18 R
285/30/18 R

The additional sizes are quite tempting as I'd like to trying running a bit more rubber up front this season to see if I can dial out a bit of understeer. Has anyone had luck fitting 255s up front with a 987 and similar wheel offsets? How about 265s?

BTW, my class rules are very limited wrt mods; you can change shocks, one sway bar F or R, brake pads, and max out your alignment but not use LCAs or camber plates. I can use 5mm wheel spacers as well, since this was a factory option.

Appreciate your thoughts.

Cheers,
DJM

Formula43 Wheel

I would recommend the 245/35-18 for a 8.5" or 9.0" wide wheel. The new BFG Rival run wide so they could create a clearance issue depending on alignment/setup.

Good Luck!

DOUGLAP1

I have run the Z2's in a 255F / 285 R combo on my Boxster S on the same OZ wheel combo that you are using, so I would expect that they will work on your Cayman. At one point I did reduce my caster setting which helped with scraping the inside wheel liner at full lock, but when I had that issue, I was running an insane caster amount (9.5 deg), and am now a better 7.5 deg caster. I do run -2.8 deg camber, so you may have some rubbing on the outside front fenders if you dont have better than OEM camber.

By the way, a new Z2 compound is coming in the fall, so try to get a deal if you buy some now.

One more caution; some of those Z2 sizes (the 275 for example) have a really large tire OD, which will hurt gearing for acceleration.

fluxwrap

Hey DJM, what did you ultimately do on the fronts? I'm contemplating going from a 245 to a 255 for the same reason - see if I can dial out a bit of understeer here in the rainy NW.

djm68

Well, this is a ridiculously late follow-up, but if it still helpful:

I've been running Potenza RE-71R in 255/35-18 F and 285/30-18 R on 18x8.5 and 18x10 OZ Allegeritta wheels. Combo works quite well, no problems with ABS or other electronics.

Cheers,
DJM

Apex Wheels

Though the thread is old, this is still a frequently asked question. As a reference point, please visit our 987 fitment guide.

Brian C in Az

I just ran the same tires but on 18x9 up front. The turn in response is amazingly quick. Totally transforms the car.