This is on an 89 IROCZ with the stock 16x8 IROC wheels all around. Thanks for the info in advance.

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1989 IROCZ28, 5.7 liter TPI, 700R-4, 2.77 Rear, Gutted Air Boxes, Flowmaster 80 series muffler with dual 3 1/2" tips, Clarion 8575 Head, Infintiy Kappa 4x6 plates, Stock 6x9's, Alumapro 10" Aluminum Sub in sealed box, Orion 400 watt amp

 

I also would like to know what the widest tires you can fit on a 16X8 IROC rim are too.

Can we fit somethign cool like 255/45/r16's or anything?

 

The 255's will definately go on the back there is no problem. You could possibly go 265 on 16's. But the front is a different story. I have 235's on the front and they are rubbing on my sway bar when ever I make tight turns. The sway bar is a suspension tecniques sway bar and is condierably bigger but even with a stock one I don't think that you could get 255's on without some modification down there.

Cristos,

Hey I saw you're from aliso, you should email me some time. I've been trying to find other people around here with thirdgen's.

Late,

Jim

 

I have 255/50/ZR16 all the way around on my stock '91 wheels which are the same size as the IROC's. The rear has no problems but the front will occasionally rub on the inner fender well during high speed turns. Nothing extreme though.

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1991 Z28 - 350 TPI, T56, McLeod street clutch, ported plenum & runners, AFPR, Holley Annihilator ignition box and wires, Hooker shorty headers w/o AIR, Flowmaster muffler, homeade ram-air, SSM subframe connectors, Kenny Brown STB, Global West steering box brace, Steve Spohn adjustable torque arm and T56 crossmember

 

I have 245/50/16 on the front and 255/50/16 on the rear. You could put a 265 on the rear, but you wouldn't get the full amount of traction out of the tire until you get a different rim size like a 17x9.

 

For road racing I use 255/50/16 GSCS eagles all the way around, no rubbing using stock IROC 16/8 wheels. 92 RS

 

I've had 255 gatorbacks and 255 firehawks on the front of my IROC = a very little rub now and then.

 

i was talking to a guy at a local tire place yesterday,a nd he said he had 255s at all 4 corners on his 86 IROC with no problems at all. i guess they fit ok. i am probly going to go with them when i get my comp ta-zrs.

-brian

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1991 Camaro RS - Ultra Blue Metallic, T-Tops
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255s all around and they only rub the plastic fender liners when I turn the wheel to lock.
not something I do over 5mph

 

How are you guys running 245's and 255's on the front when my 235's are rubbing on my sway bar? Are you using a differnt amount of back spacing? I would really like to know because 235's aren't really cutting it right now . Thanks.

 

I've got 255-50-zr16 all for corners front only rubs on the front plastic inner fender a little when I turn the steering wheel lock to lock.

Camaroguy99, if your car didn't come with 245-50-16's on it the steering stops are set further in and let you turns the wheels more.

 

I concur with Evil and 88305. I only slightly rub on a fully locked steering wheel with my 255/50/16 IROC rims.

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1989 IROC-Z 5.7L

 

Hey camaroguy, something doesn't seem right if your 235s rub a lot. All of the Z rated 16" tire thirdgens came stock w/ 245/50/16s.
As for me, like the others, my 245/50 fronts rub a little in full lock parking lot action, but they are a pretty wide 245. 255s in teh back are fine.
...ed

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Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

255s front and rear on my Formula. A little rubbing on the plastic liner when turning lock to lock. I'm running stock 16" GTA wheels with stock ride height.

 

91 LO3 has 245/50 r-16's no rubbing at all, car craft ran a guide on how to soup up 82-92 f-bodys, you can go 255's on the front w/o rubbing and with out a diff. offset. you can go 275's all the way around if you order rims with a custom offset (5.5" instead of 4.5")with the 275's they said they rub the tie rod going through slow long corners but if you have a good front suspension it shouldnt be a problem

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1991 RS LO3
mods: 14" chrome air cleaner, straight-piped after cat exhaust with one chrome dual tip on the left side.
future mods: headers, removing smog equipment, and as many cheap mods as i can find
aol s/n: budman8503

 

damn 315? thats wider then my IROC!

im sold, if anyone out there has 335's/10/R20's tell me, ill fit them on my IROC asap!

 

so did you guys end up having problems with the 255's up front?

 

no prob,back in 89 when the formula was new we got a set of take-off comp t/as from a vette 255/50/16 all 4 for 300.00 killer deal they had 12mi.they provided 1.91 60' times and never rubbed..............

 

There won't be a problem running 255 up front. You won't run into any major problems until you increase the backspacing with different wheels. I wouldn't go any bigger than 265 on an 8" wide wheel, anoy more just buldges out too much. The 255/50/R16 is a good choice, but personally, I prefer to run BFGoodrich G-Force T/A KD or KDW tires, which only come as large as 245/50/R16. So I would stick with them on 16 x 8 wheels.

 

245/45-16 Front,
255/50-16 Back,

Looks great, no problems.

 

any pics?

 

so you're saying they won't rub in the front?

 

No, it is only 5 more milimeters on each side, it shouldn't be enough to rub.

 

I have 245/50/16's on the front of my 89 T/A on GTA wheels. They rub when i turn it all the way. I remember reading somewhere that the cars originally equipped with 16 in rims, the gear boxes where different, something about how far they would go lock to lock.

 

Sorry,no digital camera, so no pics!
245/45-16 is quite common on fast cars overhere, like Porche's and Ferrari's, so I got Pirelli P-Zero at the front, and the 255/50-16 is originaly a Corvette dimension,and is also well available overhere, 245/50-16 is VERY rare here!!
(BTW I got Cooper brand).
The front of the car is slightly lower, and the back slightly higher than stock, all in all it looks good I.M.O.!