eisenfaust

So. I'm attempting to size and determine fitment for a nice set of rims on my S2000. The ones it came with suck balls, I want them gone.

Now, I'm all set as far as the front wheels go, I've got no fitment issues there in my chosen wheel.

However, the rears area a bit of a PITA.

Now for the wheels I'm looking at, the vendor-reccomended rear size is:

17 x 8.5 +42 offset, with a 255 tire.

Thats all fine and dandy, but I'd kind of like to run an 18 x 9.0 +43 offset, with a 255 tire.

Vendor says he doesnt think it will work. I'm scratching my head over this.

Going up half an inch in width (13mm, roughly), and 1mm in offset, should move the outer rim lip about 6mm outwards, and the inner rim lip about 7mm inwards. The centerline of the wheel will move inward by 1mm.

A 9 inch wheel is 228.6mm wide. Consideribly narrower than the (nominally) 255mm wide tire I plan on running.

Now, I'm told that the *TIRE* of the 17x8.5 wheel, at that offset, can cause clearance issues when the car is lowered, solved by a fender roll. It fits, but just so. The rim face on the smaller wheel is a few CM inboard of the tire face.

Given that the tire is in exactly the same place, and has exactly the same clearances, why shouldnt the larger wheel fit? Here's a diagram I did:



Stock wheel is in faded blue, to illustrate changes over stock.

Now, my inclination is to trust the vendor, but I also trust my math skills, and if the rim wasn't having clearance issues in the smaller size, it shouldnt in the larger size either, especially once I roll the fenders.

What do you guys say?

SOHCmyDOHC

Ummm... You forgot that 9" wheels are actually 10" wheels. 9" refers to the inner bead. Your pic is pretty big too! might wanna shrink it a bit.

HTH

https://www.rsracing.com/tech-wheel.html

Jim@tirerack

A 9" wheel with a 42mm offset is going to stick out of the wheel well even with a 245/35R18. The 255/35R18 is going to be even worse. I don't see them fitting without some work to the fender and or some more negative camber.

eisenfaust

Really? I thought measurement was at the lip!

Well shows you what my dumb ass knows.

Like I said, I'm inclined to agree with the vendor, but I still dont see why the marginal increase in wheel width will change anything if tire width remains the same.

silentdancer

they will fit with rolled fenders.

eisenfaust

How much negative camber am I going to need to run? I'd like to keep it in the sane realm. I've read tha the S can benefit from a touch more rear camber than front camber (or so a few alignment threads say), but I dont want to be running 3 degrees of negative camber out back. If it came to that, I'd just go with the smaller wheel.

I do have to say that your wheel/tire/drop combo looks just about perfect. What sizes???

silentdancer

17x8.5+41, 215 front, 17x9.5+41 rear 245.

with rolled fenders (rolled all the way flat) you should be able to fit easily with 2 degrees of camber.

eisenfaust

But 255s are right out?

Ubetit

Yes

eisenfaust

Awesome. To be honest, the more I drive my current non-staggered setup (225s all around), the more used to it I'm getting. The car doesnt feel tail happy. It WILL oversteer, but not without provocation.

I think a 225/245 setip might be cool.