Ok here is my issue first of all, I’m polish so I have to read things like 5 times and then get it a little then read again j/k lol but in reality I have always run the wheels that came on the cars and trucks I’ve bought over the years. I have a white 88 Iroq that was given to me, there was a few stipulations on it though, which is fine by me since I mean I have pretty clean Iroq and didn’t have to break the bank getting it lol. The car has a nice pristine set of GTA wheels on it the charcoal ones, she said she wants them back when I choose to give them back. Well I couldn't stand them on the car at first and then they grew on me go figure right. Anyway here is what I have found to hopefully replace them. My issue is with the backspacing and offsets if it will work on the car or not.


I want to do Black Standards by US Mag front and back, because id like them to match lol. For the fronts (Size:15x7/ Bolt Pattern:5x4.75/ Offset:-6mm/ Backspace:3.75"/ Hub Bore:72.6mm) and for the rear (Size:15x8/ Bolt Pattern:5x4.75/ Offset:+1mm/ Backspace:4.50"/ Hub Bore:72.6mm)

 

Those 8s will fit front and rear, so forget the 7s. Or these: http://www.summitracing.com/parts/oe...4411/overview/ these are rears, the fronts are a different part number, and are 4.5" backspacing, which can be used on the rear also.

 

oops, duplicate post.

 

I know 8's will work front and rear but I'm going for the old school stance but that may change to 8's all around. I'm just worried about the offset and backspace, I have the GTA rims on the car atm but I want to go a little different I'm sure I could buy the rims that are on my car way cheaper then $200 a rim from summit :P but I think id prefer the 15's I'm looking for a old school new school cross.

 

Do the 15x8s then, with 235/60s front and 255/60s rear. Still gives you some older look, but with better performance, and definitely better handling. I'm surprised that RonUSMC? hasn't commented yet, but his car would look the same and handle better if he put 8s on the front also. Probably his 8s aren't offered with enough backspacing.

 

If you are talking about the offset on the rear wheels, I have front wheels all around on my formula so I can rotate the tires and there are no clearance or tracking probs.

 

Here you go.
To me the Old school look is a slightly smaller tire with a slightly thinner wheel as compared to the rear.
You want a smaller dish in the front and a deeper dish in the rear with a larger tire rear than the front.
If you put 8in wheels all the way around you are defeating the whole look. Besides you don't want to put the same size tire front and rear so why use the same size wheel all the way around.


235/60R15 = 26.1 Diameter and 8.1" tread width
245/60r15 = 26.6 Di. and 8.5" tread width
255/60R15 = 27.1 Di. and 9.1" tread width
275/60r15 =28.0 Di. and 8.9" tread width
295/50r15 = 26.7 Di. and 10.4" tread width

If your going to stay with 15s and its primarily a street car I would not go any larger than 235/60r15 front on a 15x7in wheel and 255/60r15 rear on a 15x8in wheel.That set up will give you a nice staggered look with a slight rake.7in.wide front wheels give you just enough dish and the 8in. wide rear wheel gives you a nice deep dish. The reason I prefer that combo for primarily a street car is IMO the larger, taller 275/60r15 look like your ready to launch a 500hp car at the track and there's nothing wrong with that if that's what your looking for , and then there's the 295/50r15s that will not tuck without major well work and are total overkill "again" for primarily a street car with 15in. wheels


Personally I prefer the 235/60r15 on 7in. wide wheels front (26.1 di) and 255/60r15s on 8in. wheel rears.(27.1 di)
That gives me a 1in. taller tire in the rear in a respectable size and that IMO is perfect for my street car.
Heres a link to a thread conserning the tires = https://www.thirdgen.org/forums/whee...er-cobras.html

 

Also the 235/60r15 is 1" smaller in diameter and that is what gives it the look I’m aiming for but it’s not a narrow tire. It is an 8.1" tread width and that’s only 1" smaller than the 255/60r15s 9.1 tread width. Hold up a ruler and take a look. That's plenty of actual tread on the ground.
Granted it’s not a monster like some are putting on the Corvette style wheals but it’s not supposed to be.
As far as back spacing is concerned the 4.5" seems to be a favorite here front and back with tires and wheels in this range. They will be 3/4" further in than what you see in the photos below.
My wheels are only offered in a 3.75 BS so that's what I run front and back and this is what they look like.
Perfect to me.

 

Not bashing Ron, but explaining what he seems to have not grasped. First, because he spent so much, and he loves the car as is, this blinds him to how his car looks. The front wheelwells look empty compared to the rears. I've run Cobras and Radial T/As in the 235/60 size, on 8s, on the same third-gen. The T/As not only have wider tread, but look better and don't drive any worse in any condition. You can't get Goodyear 235/60R15s anymore, but their STs handled the best, and their GT2s were the widest. So much for looks. Performance. To me, this is more important than looks. Wider wheels support the tires better. In '82, a new Z28 on stock 215/65r15s fitted to the stock 7 inch wheels was tested to pull 0.87g, and that's as good as the '85-'90 IROC-Zs did on 245/50R16 Gatorbacks. Putting 235/60s on 7s looks beefier, but doesn't improve that number. With mods, 245/60R15s, of the same Eagle GT, did give better numbers, but on 8 inch wheels and with suspension work. But not enough wheel width hurts everything but ride quality. There was a scientific test done, on a third-gen, back in '85, replacing the 245s with 255s actually gave worse results. I learned this from that arrogant old guy who sold me my hitch, but he dug out some damaged old magazine pages as proof. 8 inches is the right size wheel for 235/60. I've personally seen 235/60s fitted to wheels known to be 6", and as wide as 10". On 8s it ends up as square as 215/65s on 7s. Those 255/60s really need at least an 8.5 incher, and a 9 wouldn't be wrong. Some guys on here mistakenly think it's the inner sidewall of the outer tire that does the cornering, but this results in tire squirm so bad that you can't help but feel it, when driving at the limits of your tires' grip. This is why the most serious efforts always choose wheels, rules permitting, at least as wide as the contact patch of the tires. 235s on 7s doesn't match this. Cars are more fun to push hard when they're both predictable and linear in their response. I'm not saying that 7s front and 8s rear isn't the old look, it is. But that's less obvious than 235/60s front and 255/60s rear. And our cars being front-heavy, the front tires do most of the cornering. That's why it isn't as important if the rear tires are slightly too wide for their wheels. Wider tires on the rear was never factory on nose-heavy cars. The closest you'll find is the '90-'95 ZR1. Not nose-heavy, but the wider rears weren't for the power. They were for applying power sooner when coming out of corners. This isn't why we do it, we do it for looks. It's easier to fit wider when there's no steering. If we only drove straight, we could all tuck 335s on the fronts as well as on the rears. I guess you don't care about cornering if you'd consider 15x7s, but these are cornering cars. That's their only real advantage over Mustangs. Driving a Camaro and make it unable to corner is like ordering a Modern ponycar with the V6, it defeats the whole entire thing that makes the car a standout.

 

Cp88Iroq,
I believe your choice of wheels and the BS you referred to will work nicely.

cosmick,

I did not take your comments and suggestions in a negative way but just wanted to reply explaining a little bit about me and mine.

I chose this look because it fits my personality. I’m old school.
The car was built for the street focusing mainly on getting the look I wanted. What you see was not just thrown together.
The style of the wheel, the tires, the rake, etc will never change for me .I present it as it is and anyone that wants that staggered look can use mine as a template.

When you see my car setup like this its obviously showing its limitations concerning hard cornering performance but it is my DD street car not a canyon carver. Besides it says 1/4 mile car more than anything else. I push my little 5.0s Eaton posi. and 3.42s hard off the line when I see it’s clear.I bark the tires from first to second and then again from second to third. See strait line and that's fun for me.

 

call a tire shop ive had factory 8 in rim on my 88 iroc with 245 50 16 and it handels like nothing ive ever drove. the offsets are diffrent from front to back, but every time i try to buy after markect rims the off set is the same.go figure any body got a nice set of 88 16" rims

 

Although I have never seen or heard of a stock 82 pulling 0.87g on 215-65-15 tires, he has a great point.

GM did never put staggered tires on the 3rd gens at all - with 54 to 57% on the weight on the front, putting a 20mm to 40mm narrower tire up front just adds to understeer. Even a 50:50 3 series BMW handles better with a square tire setup than the staggered ones that some sport models roll out of the factory with.

But you have freedom of choice with your own car - but choose wisely as you can change the whole handling experience with a few minor choices.

Also - the wider a tire you go on a fixed width wheel will give you sloppier handling, ditto for sidewall height. Too much and you degrade handling - a 235-60-15 will feel sloppier than a 215-65-15 tire on the same 7" wheel.

That all said, if your wheels now are in good shape, why not get a nice set of BFG g-force sports in 245-50-16 and call it a day? You will have the looks, handling, and they still look old school (they did put them on 87 and on - 27 years old now).

 

i have 18in us mags on my car, see my sig

 

Thanks Ron after reading his 4 times I see your point lol. I feel pretty much the same, I like the smaller 15" wheels with more tire filling the wheel well then wheels, never been fan of that personally. This car is always going to be a street car, everything is original on it except it has B&M shifter in it, nice but dosnt make it a drag car like most people think lol. Im going for a classy look not a 20" dubs look lol. Besides I have a 89 camaro that I'm currently starting to build for the track so why fix it if it isn't broke. Pictures are in my album. In 1988 the 16" wheels became a option and standard was the 15" wheels if my research is correct and im ok with going back to 15"'s from the current GTA 16"s.

Cosmick The car dosnt corner now with the current 16"x8" GTA wheels, all 4 tires I think are the same on the car which may be the issue, but like Ron Id rather run 1/4 mile then twist and bends (again im polish lol) but again itsa street car only. The car is also a auto with a 700r4 in it so what is really the point of cornering to me? At this time taking a sweeping corner at anything above 55mph I have to grip the wheel and hold on so it is what it is. If it stays the same or gets slightly better/worse i'm ok with it. the biggest reason why is because it is not my daily driver, hell I feel bad taking the car out in the rain. I really dont do donuts or burnouts or beat the **** out of this car it has 139k or 239k mile on it. Its a hop in take her for a drive nice sunny day type of ride for me.

Ron so you think the Offset and Backspace below will work and look correct with the right tires you mentioned on the car without rubbing hammering beating and or sticking out of the wheel well lips/flares?
15"x7"s Front 15"x 8"s Rear
Offset:-6mm/ Backspace:3.75" Front (Tires 235/60r15?)
Offset:+1mm/ Backspace:4.50" Rear (Tires 255/60r15?)
I'm worried because if I order these wheels at somewhere around $155 per wheel with taxes I'm gonna be a little upset if i screw the pouch on it.


86iroct5 The look and work really well on your car, although way to much wheel for my taste. I like a little more tire personally but then again to each his own right. If you dont mind me asking where you got them, price and what not thank very much

 

thats what i figured, just figured id post to give you an idea of how they fit on the car since the offsets are nearly the same.

as far as price i forget what i paid. but i got them off www.carid.com

 

OK,
If you insist I will play the game only because it might be fun.
We are talking about 15in wheels only.

235/60R15 = 26.1 Diameter and 8.1" tread width
245/60r15 = 26.6 Di. and 8.5" tread width
255/60R15 = 27.1 Di. and 9.1" tread width
275/60r15 =28.0 Di. and 8.9" tread width
295/50r15 = 26.7 Di. and 10.4" tread width

Lets break this down to the actual amount of tread widths compared to the others. Then we can see what all of the fuss is about.

First if you look at the chart above you will see the difference in the tread width of each tire.

The 235s 8.1" tread is only .04 thinner than the 245s.Thats 0.02 on each
side of the wheel.

Also its only 1" thinner than the 255s.
That a whopping 1" difference at a staggering 1/2" on each side of the wheel.

Its thinner than the 275s 8.9" tread width buy 0.8" that's 0.4 each side.
Even the 295s tire width is only 2.3" difference than the 235.
That big boy is only 1.15" on each side of the wheel.

I took all of this information into consideration when picking my wheels and tires.
As far as the wheel width goes concerning the proper fitment of a 235 and 255 ,they fit exactly in the middle of the suggested widths at Tire Rack.


If I went down any further than the 7" width or any wider with the 235 tires I could see there could be a problem meeting your concerns about my DD street car that is obviously set up for the 1/4 look.
I believe any one with an opinion should post photos of their cars so we can get a look at what you are running.


This is my first build and started as a wreck and have been working on it for about 9 years now.
The car was on its way to the junk yard. I took a chance and payed $500.00 for it. Needed a paint job, fuel pump ,water pump , power steering unit ,new steering column ,intake manifold gasket, front windshield ,new front bumper cover and lower valance, new rear hatch motor, some of the interior including head liner ,door skins.Etc

 

Cp88Iroq

As far as fitment go’s I will say yes they will fit fine but you must be the one that has the final say. Look at the photos you see and do the math.
Your fronts will set exactly like mine but your rears will be in the well a 3/4" further than mine. That's the best I can do.

 

check out my pic of my rear wheels, granted my tires are a bit wider, but the rears you are looking at will sit 5mm towards the outer lip, which is spot on for fitment IMO

 

You used to be able to copy and past photos on this forum.

86iroct5,
Any way I love your car and the way it sits.
Those wheels look great.
The OP is going to be happy he picked them because they incorporate the old school look with the new.

 

Thanks Im looking to fill the rear wheels well as much as possible but not sticking out so its clean and not gaudy Your wheels fill them wells perfect as well as Rons both different style but very good looking non the less

Man you hit it spot on, when 86iroct5 posted his car I sat back and said damn now they look good on his car and mine is white so its really gonna make the car stand out and become its own

 

Ok, I decided that when I paint my car I'm going to buy new wheels (The AR 23's). It might be a little while until then. Now not to bring up this subject as if I'm keeping the GTA wheels on my car, because I am not. I remembered that on my 89 camaro I have had since I was 14 (I'm 25 now) There is/ was a half decent set of cragars on it. Well folks that's what I'm going to use for now just need new tires lmao because as you will see they are very shot, still hold air but shot non the less. These wheels Ive had for years took me a while to get off since I didnt have any cap locks or lug locks that fit lol. I'm going to post before and after pictures since they required alot of attention. I'll also post the stamping on the back of them for everyone to check out. I feel like im reviving the dead because no one around here has them nor has most ever seen these wheels b4. The size of all 4 are 15x7/ -11mm offset/ I measured 3 9/16" backspacing which I'm pretty sure is just 3.50" or 3 1/2" but I'm meticulous lol.

 

These are before doing anything to them, I'll post a few.

 

This is after etching them with wheel etching spray or acid etching them. I got it from Autozone.... They had no clue what it was for lol.

 

Left on the first picture is after using Goo Gone Automotive Formula steal wool 00 Grit and heavy duty turtle wax rubbing compound. Right is what they looked like after just etching with steal wool 0 Grit. The second picture is the finished product of all 4 wheels.

 

The next 2 post since they only allow 3 Pictures a shot are the wheel stampings.

 

The rest of the stampings.

 

I think I'm going to go with the same tires and size as Ron U.S.M.C. Is using which is 235/60R15 for the fronts and 255/60R15 for the rear Cooper Cobra's if it is still possible whithout sticking out of the wheel wells and without rubbing. These wheels are all 4 the same so I'm not sure just how thats going to work. Any thoughts or suggestions.

 

Sorry forgot to add this, The tires that are on the wheels that worked fine on my 89 camaro are 215/65R15's I know that tire would fit but its a little to skinny for my taste so with the huge tire size change would it work is what I'm asking thanks