mvs1

Scored an incredible deal on a set of 17×9.5 35 offset Enkie GTC01's from a race team... $750 shipped. These were the back up set and were never even taken out of the boxes, only thing wrong was 4 of the 8 lightweight valve stems had been lost. Went with Nitto NT 555 255/40 17 front and 275/40 17 rear. Because of the slight difference in offsets from my "track" setup (Enkei RPF1 w/NT05) had to raise the ride height .5" which is fine since she was lower than I'd preferred anyway. Rained on and off all weekend so didn't get any good pics out in the sun.

Johnny Kommavongsa

iTrader: (13)

very nice, thxs for sharing

lOOkatme

iTrader: (19)

You will get better results with a 245/40/17 front and a 245/40/17 or 255/40/17 rear set up.

I have been working with a local Miata racer here who was fitting large tires to his 8" wide wheels, I told him about stretching the tires onto the wheels and we dropped from a 225 width to a 205 width and said the difference was amazing and he didn't realize how much of a difference the stretched tire mattered due to the better mechanical grip of a stretched tire.

mvs1

I understand what your saying, that the narrower the width on the same sized rim will act to reduce the profile therefore conceptually reducing the amount of the sidewall flexing. The difference between 255 and 245 is minimal so I would have to drop at least two full sizes before I'd see any significant benefits, go to the link below and check the numbers. You'll also see that for my rim width they don't recommend going below 245, I know I could but it's not recommended. If you put the numbers you mention into the calculator you can see that 225 is oversized for an 8" rim, he needed to have a minimum rim width of 8.5" running a 225. 205 is the maximum width recommended for an 8" rim, so actually he wasn't stretching the sidewall, he just went to the recommended size.
Custom rims, wheel tire packages for your ride - RIMSnTIRES.com

When I have marked my sidewalls to gauge how far the tire rolls onto its shoulder under hard cornering, I have found that the proper air pressure makes all the difference.

gracer7-rx7

iTrader: (16)

Looks very nice. Good color too.

Too bad about your engine though.

lOOkatme

iTrader: (19)

Next time you purchase tires, try a 245mm width, measure the bead to bead width, you want a wheel width slightly wider than the bead to bead width.

for exmpale, a 265/35/18 RE-11 I have sitting in my garage measures 10.1", you want to run it on a 10.5" wheel width. it puts the sidewalls under slight tension or stretch and maintains a great contact patch when turning.

Flyweight

iTrader: (1)

lOOkatme has a very different perspective on tire sizing.

Is a 245/40 17 faster on a 9.5 inch wheel than a 9 inch wheel? Of course.

But that is not the question.

Is a 255/40 faster than a 245/40 on a 9.5 inch wheel? Yes! Just look at what HPDE/Autoxers run.

You are also LS powered so you need some beef in the rear. I am willing to bet the house that a 275/40 like you are running is faster than a measly but stretched 245 with all that power that the LS produces.

Nice set of wheels BTW!

mvs1

Honestly guys the difference is miniscule and I can promise you that a 245 on the back of my car is absolutely useless as the 275 has hard enough time retaining grip, especially while cornering under throttle.
Another issue that can occur when trying to "cheat" your way to a lower profile sidewall is that under extreme conditions you will end up pushing the tire past the shoulder and onto the sidewall earlier than if you had not deflected the sidewall.
You can kick this ball back and forth and each side has benefits and draw backs. Not too seem arrogant, but I know exactly what I'm doing when it comes to setting up my car and this is as close as I could get to the perfect set up for what I wanted which was a good street set up.
Appreciate and unvite everybody's inputs but please don't turn my thread into a debate.