Saw this at a local car show and had been turned off by 18's until I saw em 40 series tires, just what they needed, a little more meat... But I would get them polished, im not a huge fan of chrome on our cars..... anyways, is there gonna be a prob with rubbing, or anything at all?

Will

 

yeah...

https://www.thirdgen.org/techbb2/sho...wheels+rubbing

http://www.iroczdesigns.com/

 

im running 18x8" Eagles with 225/40r18s in a BFG euro T/A, and with my car slammed (im running bags) i can steer lock to lock with no rub.

 

Depends on the width of the wheel IMO. I'm running 18x8's on the front with 245/40/18 tire and no issues at all. The 40 sidewall on the 245 was the best choice as far as maintaining the overall OEM wheel/tire dimension (as or close as possible). But because the rears are 275 (on a 9.5" wide wheel), I had to go with 35 series sidewall to retain OEM overall diameter (or as close as possible). So if you ran 18x8 front and rear and a 245 wide tire, the 40 sidewall should be fine. if you went wider, the sidewall might need to go down to 35.

 

oh 40 series...I was thinking 45 for some reason.

I think those wheels look so awesome polished and painted in 18". Got anymore pics of that car you saw at the show?

 

245/40/18 is the proper tire for an 8" wheel. that's what you should be running, now different companies and makes will effect how it looks overall though.

 

Correct me if I'm wrong (as I'm sure you will anyway! ), but I'm under the impression that the overall tire diameter on our cars was 26" (at least it was on my 89 RS, which had stock 215R65x15, which gives ya a 26" diameter..the optional 235R60x15 gave 26.1"). A 245R40x18 tire has a 25.7 diameter... what you really want is a 255R40x18, which gives a 26" diameter (assuming you actually WANT a replacement with the same diameter).

 

But how do you go from a 45 series with a 16" wheel to a 40 series with an 18" wheel. Shouldn't it be 35 series? I mean I'm all for the 40 series, the 35s are way to skinny. Just wondering

Heres one more pic for you all....



Will

 

at least in my own instance and most iroc/z28 optioned cars the correct tire that came from the factory using factory speedo calibrations and the like was a 245/50/16. If in fact this is the correct tire that came on your own particular vehicle that would in fact mean that to keep the correct specs running an 18" rim you would in FACT want to run a 245/40/18.

that's of course if you actually want the REAL replacement size tire.

now if you had the standard optioned iroc/z28 235/55/16 factory performance tire then the 235/45/18 would be the correct option.

if you had an rs with a 215/65/15 touring wheel then in fact you would want to adjust accordingly.

from gm their ideal performance tire size for the 8" wheel is a 245/50/16 which is the same for most tire manufacturers. now if you want to upsize your 8" wheel to a 18 then it would be only right if you planned to keep the specs and run a 245/40/18. then again obviously just about any of these combos can be ran.

 

good to know man, thanks. I think I am sold on these now!

Will

 

I'm requesting pics if you get them

 

Front wheel (40 series on 18's):



Rear wheel (35 series on 18's):



Wish they were both the exact same angle, but notice that even though the sidewalls are different, they look pretty much the same from the side of the car. It all depends on how wide the wheels are. In my case the fronts are 245's (on 8" wide) and the rears are 275's (on 9.5" wide). If both wheels were 8" wide, I'd be running 245/40/18 on all corners.

 

I run 235/40/18 in the front, 255/45/18 in the rear, the rear wheel looks great! looks like I need no lowering spring....but 255/45/18 will rubs in the front, I think you should run 245/40/18 in the front if you wanna to go wide!!

 

love that car..

 

I just got some 18x8 IROCs and went with 245 40 18's on front and a 265 40 18 on the back. They look good. I was afraid the 265 on the back would be too wide for the 8 inch wheel, but I think it's about perfect. It gives the car a little of a rake too. The 265 is actually about an inch taller than the 245. I haven't really taken any pix, but will post them as soon as I do.
Todd

 

What do you guys think?

 

not my cut of tea.

It dont match the car veyr well for some reason. Might just be the light, no shine on the car but plenty of shine on the wheels. Try to wax the car and take more pics. Something. I'm sure they look really nice in real life as most people dont brag about stuff if it dont, but in the pics its not looking right.


Just my $0.02



Shane

 

I'll agree on the wax, I haven't done it this year. But, the lighting was all wrong. Here's a pic with the old wheels and you can see the shine in it.
Todd

 

i think it looks great except you have poor camera angle for lighting position so it naturally throws it off. beyond the fact that your need to lower the car alot more to run that large of a wheel and look ok i think it's good. you should have parked the car so the sun was against the side not the nose...

 

looks awesome... just lower it and wax it.

 

Ok, this is a better angle and shows that it does shine. You guys and your wax.....

I can't really lower it too much because I have the southside rear setup. The crossmember drags the ground every once in a while right now. I think I might section the crossmember a little and get it closer to the bottom of the car so I could get it down a little though.

Todd

 

it really looks like it's a huge lift on the car....maybe get a reference picture by putting your hand in between the fender and tire. if you can fit more then then 3 fingers it definately needs to go lower. looks really nice and clean though, almost 17's in the pic. i don't see how anyone can say 18's are too large as it fits nicely.

what brand and how do you like the ride?

 

ROFL...when I first read that, I thought it said "put your HEAD in between"
Todd..where'd you get the wheels? Do you know what the offset is? I'm thinking of the same ones for mine, just not sure tho. They do look a little bigger overall than stock..and yet..with 245/40 on there, the overall diameter is actually 3/10's of an inch less, so I can't quite figure out why they look big. Maybe its the offset..maybe it's just that there's so much more metal. I'll likely go with a 1" drop, but still...I'm just not sure...
Thanks

 

I can assure you the car doesn't have a lift kit. I'll take some more pictures with a better angle and see what happens.

I got the wheels on ebay. homeboyzrimz has some good prices on them. They seem to be a good company too. Mine are 18x8 with 0.0 offset. The offset is about perfect.

The tires are BF Goodrich KDW . I can't remember the exact specs, but the fronts are about 25.5" tall and the rears are about 26.5" tall. The ride is a little rough but not bad. I just feel more of the patches and stuff on the road.

Todd

 

I too run the 18" Chrome IROCS
245/40/18 on the front
275/35/18 on the rear
1" eibach drop springs
KYB AGX Shocks
no rubbing
no problems

 

thats hood actually looks pretty cool on your car

 

IRONNParts....got any other pics at different angles? I'd like to get a good look at how those wheels look with the drop. Thanks

 

not sure how old this post is but did you have a better side shot of the car? what size tires are on it?

 

Hmmm...in my opinion, the 40 series tire look too skinny on the car....eventhough they may be the 'right' tires to get technically.
I think the 45 series is the best way to go...again..just my opinion.


Here is a good comparison. First pic is the 40 series, second is the 45 series. I think the thicker tire just adds more substance to the wheel, and gives it that extra pizzaz. Also, thirdgens are large cars. You need to offset the look of this big body with some meat on the tires.

<img src="http://images.cardomain.com/member_images/2/web/314000-314999/314746_151_full.jpg">

<img src="http://www.iroczdesigns.com/Links/baersnew3.JPG">

 

ok , im gonna ask , im sick of the 35 series in the back , i want to run 275 40 18s , are they gonna hit , It looks like they might but im not positive, I have 18x9.5 with 5.5 bs . The stock tires are too short , want something in the 275 40 18 . I think a 285 35 18 is also too short too . So with a 275 40 18 fit , with 5.5 bs and a sportline drop , you can see the pics in my sig .

 

damn this is an old thread

 

some good info on here..

 

Nice !!!!! IM building an 89 IROC Now !!!!