ex10psi

I know... did this guy use the search feature????

Yes, I did and was not able find much info about the 255/35 front and 315/30 rear, toyo R888's fitting on stock OEM 18 inch wheels. What I was able to find in my search was that this combo seems to keep the rolling diameter of the 6GT3 close to stock, and worked well for some running wider, aftermarket race wheels. But anyone try this size combo on the stock GT3 wheels??

Also, I found conflicting information about running the 245/40 and 305/35 RA1 combo. We know that the 305/35 is really tall in the back and will net me even taller gearing. But, will it really NOT work on the 6GT3 due to ABS issues or other issues like stability? Has anyone REALLY tried this combo and care to share experiences?

Thanks!

ex10psi

Thought I'd post a follow-up to my original question here in case others have wondered the same.

I tried the 245/40 and 305/35 RA1 combo on the stock GT3 wheels last weekend, on track after five 20 min sessions I had NO issues with this combo. No ABS issues, no issues with stability, everything was spot on and I was very happy with the car's performance, level of grip, it was an awesome HPDE day. Track was Portland International Raceways (PIR).

Yes this set-up is tall compared to stock rolling diameter but I did not notice any significant gearing changes (and I'm very familiar with PIR). Honestly, for a simple guy like me (not a race car driver) I have no complaints.

TurboCup87

THanks for the info. I'm still trying to figure out my track tires for an O/W stock suspended 6GT3. I'm going to use CCW wheels. Still haven't figured out the best width for these, but there has been lots of discussion. I'd like to get as much front tire as will fit, to try to dial out as much understeer as possible. Leaning towards 305 or 315 on the rears. I am leaning towards Nitto or Toyos R compound tires. Any others with expeience or advice on fitment for this scenario?

roberga

ex: thanks for the info. It was great meeting you and look forward to lots of track day this year. The new surface in Portland is going to make it harder to put up with Seattle.

ex10psi

Hi roberga, nice meeting you also! You were really moving out there on your street tires! I'm still a little new to tracking GT3's so you'll have to give me some pointers, and/or maybe I can ride a long one of these DE days?

Anyway, I'll definitely see you out at the next event!

DanH

What is the advantage in running oversized tyres? Toyo make 888s in OEM sizes...

ex10psi

I do not see any advantage in running oversized tires. In fact, it is not recommended BUT... does not cause any adverse issues based on my 120 miles of track experience.

My next set will be the R888's either in stock sizes, or go wider but keep the rolling diameter close to stock as possible.

I went with these RA1's as they were readily available with a low price point due to just a couple heat cycles on them. But ideally, I would have gone with the R888's at stock size or close to stock rolling diameter.

DanH

Oh fair enough. I asked because the wheel arches are tight on the 996 and even with stock R888s I had to have the arch liners shaped and moved to provide clearance.