What are the biggest (widest) tires I can put on Ray's rims?
 

I just purchase a set of Ray's Track rims that will be delivered in a couple of days. I was wondering if I get the poleposition 03's what the maximum tire size I can get without going to far.

The rim sizes of the rays are 18"x8.0"(front)/8.5"(rear) .

I have performed a search and I have found this:
Front - 245-40-18 and rear 275-40-18.

Would that be the biggest or could I go bigger? (Wider)

Thanks for the help, I will soon have a Track/Touring fully loaded Z in the garage!

I just got a set also and put 245/45 in front and 255/45 in back. 275 are not recommended for wheels less than 9 inches in width although people have put them on, I think it is too much and if you drive hard or plan to track or autox you might have problems.

I would go with the 245/255 combo in a 40 or 45 profile.

So is that the definitive answer?

Do you have the Ray's track rims on your Z? The Ray's are 8.5" in the rear, just a tad wider than the touring 18's.

So does anyone else have an opinion?

I just want to know for sure, what is the widest rear tire size I can fit on the 8.5" ray track rims.

Thanks

Well sorry you haven't gotten much response but it is not a matter of people's opinion but more of what the tire manufacturer's recommend, I saw where people put on 275's but that is just too much for these rims, being Z rated their sidewalls will be stiff and not show too much sidewall bulge but the stress is there and it is not good for the tire or rim, trust me upgrading in tires alone will be a huge change so going from 245 to 255 in the rear will be just gravy plus the high performance tires like the Toyo's and S03's have more treadwidth even at the same sizes than the RE040's so it is not just the 10mm you will adding more treadwidth anyway.
Here are some links for spec on the manufactures for the different tires and you will see the range of rim widths for the various tires sizes:
Toyo Proxes T1S
Bridgestone S03
Kumho MX
Pilot Sports (pdf file)
And here is a pic of mine with the Toyo's
http://www.sfzcc.com/Tiresside.JPG

thanks for the info and the links.

looks like I am going to go with:
245 40 in front and 255 40 in rear.

westpak-

Since you're reducing some of the rear contact patch bias with those sizes, do you feel like the car understeers less?

Thanks,
Jason

You should really go with

245/40-18 Front
255/45-18 Rear

That's slighly closer to stock, and those are available in S03s. That's what I'll be going with once my stock tires are toast!

It does feel like it improved taking coners a lot tighter, but all I have done is normal street driving. I want to do an Autox to compare because it definetly had understeer at the Autox on the old tires.

Might want to drop the front air pressure a couple of pounds if you're still getting significant understeer at the autox :)

Alright then! There it is.

Thanks

west, another Q.

Do the 245s up front make the steering feel heavier?

They did at first, that was my first reaction when I got in but now I don't notice it I guess I got used to it.

sorry for the late post, but I've been running 245/40/18 front and 275/40/18 rear on S03 for a couple of months. no problems at all and they look and feel right.

the 9" rim thing varries from manufacture by .5 or so. I went to the outside spec and took the 275's. I autoX with a completly diffrent set, but my 275's are good even on the hard driving I put them through on the streets (Daily)

I don't suppose you have pictures to show close to the wheel? I'm curious what the tire bulge looks like.

here ya go

I love to autocross
 

just a few points

If you plan on autocrossing in Stock Class you have to use the rim size the car came with. If your Z came with 17s then you can't upgrade to the track ray 18s and still be in Stock Class.

I have a track and it seems the 245/40/18 front with the 255/45/18 rear work the best.

I am using the new Goodyear Eagle F1 GS-D3 and no longer have a understeering problem. In fact the car now oversteers. I need to find the right tire pressure now.

why is nobody mentioning 265's? seems like its inbetween conservative and ballsy...

I'm now running 275 Rs all around on my OEM track wheels, and zero problems whatsoever. Several hundred track miles on this setup and I couldn't be happier.

I ran about 15K miles on my 275s on the stock track rims, and had absolutely no problems. They felt great, in my opinion. When I had them put on, the installers at the local shop seemed a little skeptical about the size at first, but said they ended up fitting 'perfectly.' My tires were the Nitto NT 555s.

just curious all bark, how much did you buy the track wheels for? i have been considering selling mine but then i also have been wondering how wide a tire i could put on them as well. this was the exact topic i was about to start haha.

holy geez i just realized how old this thread is, can someone tell me how much track wheels are going for now-a-days?