Need Help With Rota 18x9.5s

[its_ok_im_phong]

Hey guys
Im sorry if this has come up before but ive been searching for a fair bit and have been on Jimmy S's thread for ages and cant find anything. I plan to buy new wheels but dont know what to choose ive been looking at the Rota Grids but dont know which size. the two sizes ive been tossing up are.

The
18x9.5 +38
And
18×8.5 +44
Im planing to run 235/40/18

i know that they will booth fit with abit of work but i dont want to run any more than 2 degrees camber if anyone has info i would appreciate the help thanks

sorry this is my first post too so please dont hate too much

[Manaz]

You'll need quite a bit more work to fit the 9.5" wide wheels.

9.5" +38 wheels will stick out 16mm closer to the guards and give you 7mm less clearance to your suspension than 8.5" +44 offset.

There's also absolutely no reason to run a 9.5" wide wheel to run 235 width tyres - in fact, I'd say that's bordering on crazy - you'd end up looking like an mad VW stretch fetishist (by which I mean the contact patch on a 235 width tyre is narrower than a 9.5" wheel, and this is both unsafe and looks stupid). For a 9.5" wheel, you'd want 245 width tyres minimum, and 255 might be more appropriate. For those widths though, you'd want a lower profile, probably a 35. And those tyres are going to get expensive...

[its_ok_im_phong]

Thanks for the info manaz hahahah goes to show how little i know about wheels and tires thanks mate i guess ill go with the 18x8.5s

[Manaz]

Thanks for the info manaz hahahah goes to show how little i know about wheels and tires thanks mate i guess ill go with the 18x8.5s

No worries. I didn't intend to 'rain on your parade', but by the same token, I think you'd only end up in trouble had you pursued the 9.5" wide wheels and 235 width tyres.

http://www.willtheyfit.com/index.php?wi ... 44#content

That's comparing 235/45R17 tyres on 17x7.5" rims (what I run) with the 235/40R18 tyres on 8.5" rims as you're considering.

http://www.willtheyfit.com/index.php?wi ... 38#content

And that's comparing my setup with the 9.5" option you were considering. As you can see, that's quite a difference.

[its_ok_im_phong]

Thanks for the info manaz hahahah goes to show how little i know about wheels and tires thanks mate i guess ill go with the 18x8.5s

No worries. I didn't intend to 'rain on your parade', but by the same token, I think you'd only end up in trouble had you pursued the 9.5" wide wheels and 235 width tyres.

http://www.willtheyfit.com/index.php?wi ... 44#content

That's comparing 235/45R17 tyres on 17x7.5" rims (what I run) with the 235/40R18 tyres on 8.5" rims as you're considering.

http://www.willtheyfit.com/index.php?wi ... 38#content

And that's comparing my setup with the 9.5" option you were considering. As you can see, that's quite a difference.

Wow they are alot wider than i thought to be totally honest again thanks for the help do you reckon there would be any rubbing issues? Because the car will be lowered on a set a billys and some sti or tein springs.

[dr20t]

I've got work kiwami 18x9.5 +38 that I'm going to run soon with 235 tyres stretched

A 245 tyre is recommended for 9.5" so it's a slight stretch to run 235.

Yes it's not ideal for performance but this is not my track setup and with the speeds you see on the street this is not insane

Stretch is a means of fitting wider wheels with concave (that you can't get on narrower rims) as the wider tyres won't clear our guards without ridiculous camber

[owen]

There's also absolutely no reason to run a 9.5" wide wheel to run 235 width tyres - in fact, I'd say that's bordering on crazy

Lol my 1'44 at Winton in my 86 was with 205 street tyres stretched onto a 9.5" rim.

[Manaz]

I've got work kiwami 18x9.5 +38 that I'm going to run soon with 235 tyres stretched

A 245 tyre is recommended for 9.5" so it's a slight stretch to run 235.

Yes it's not ideal for performance but this is not my track setup and with the speeds you see on the street this is not insane

Stretch is a means of fitting wider wheels with concave (that you can't get on narrower rims) as the wider tyres won't clear our guards without ridiculous camber

I'm surprised (but don't doubt your knowledge!) on the 245 recommendation for a 9.5" wide wheel. 225 is the standard recommendation for a 7.5" rim, people looked at me funny when I went for a 235, I was told it's too wide. A 9.5" rim is ~5cm wider than the 7.5" rim - meaning, all things equal, you want a tyre with a 50mm wider tread. From the "ideal" 225 tyre on the 7.5" rim, that means a 275 width tyre on the 9.5" rim (and to dial it back, a 245 or so on an 8.5" rim)!