Tire Size

[1987Rock]

How big of a tire can you fit into the stock wheel well with the 1987 Iroc 16" wheels? I know the wheels are 16x8 and should be able to fit about a 265 in there, but I'm not sure if the backspace would effect that.

[jaykar]

Hi,

255 on the rear, 255 on the front are probably going
to rub a little

Later

Irocing

[92BLKL98]

Originally Posted by jaykar

Hi,

255 on the rear, 255 on the front are probably going
to rub a little

Later

Irocing

I had 255's on my '92 fine on the rear slight rubbing on the front. I went back to 245's til I can afford 17" wheels

[The Project]

Good to know. I was going to put 255 on a set of 16" IROC rims I picked up for $ 100.00. But I'll stick with the 245.

[Daniel U]

I had 255/50/16 on, but what if you go with a 60 series? Can I get a bigger footprint? Just curious. I have home made slicks on the rear and I'm shopping for tires tommoro. Thanks, Daniel U

[Red92RS]

60 just means the sidewall will be bigger and the tire will be taller, 255 is the width of the tire so that is what gives the "footprint".

[Daniel U]

Very true, I suppose I should have been more specific with my ? I am only shopping for BFG's and I realize they only make certain size tires for 16's. I wonder if they make 16/285/60's if that would make a larger foot print(and if it would fit) than the 255/50's that I had. They only offer a drag radial 255 now, and this is my daily driver, so as much as I would love the traction, they aren't practical right now. I suppose I might try thier site 1st. duh

[Red92RS]

Are you looking at the BFGs for the best tire or best price? Best price for their base performance tire would be the GForce Sport, Best wearing tire would be the GForce KDWS, better gripping would be KDW, and the best gripping tire and the most expensive would be the KD. If you have a 16x8 wheel i wouldn't go wider than a 255. If you want something like a drag radial the best one I know of right now is Mickey Thompson ET Street and everybody I have talked to loves them much better than BFGs drag radials. Let me know what you want in your tire and I will try to point you in the right direction, as I sell them for a living.

[Daniel U]

Originally Posted by Red92RS

Are you looking at the BFGs for the best tire or best price? Not necessarily either. I just feel comfortable with my BFG's.Best price for their base performance tire would be the GForce Sport, Best wearing tire would be the GForce KDWS, better gripping would be KDW, and the best gripping tire and the most expensive would be the KD. If you have a 16x8 wheel i wouldn't go wider than a 255. If you want something like a drag radial the best one I know of right now is Mickey Thompson ET Street and everybody I have talked to loves them much better than BFGs drag radials. Let me know what you want in your tire and I will try to point you in the right direction, as I sell them for a living.

I guess I've always wondered what the IROC would look like with a taller/wider tire. Oddly as it may sound, performance wasn't 1st on my mind. I have ran both the top of the line BFG with both 245 and 255 and noticed little difference. I know the 255 drag radial will out perform the previous tires I've owned. I also know they wont last as long. I woud have just continued with the GForce 255, however, they only offer the 255 in the drag radial. My car gets way to much wheel spin for a tired(160k and burns 1.5 qts. of oil) stock 350(5.7) motor. I go through 1st and scratch 2nd. i know that there are obviously other issues I need to address. I have LCARBS and went through most every suspension part, minus the SFC's. I have 2 wheel peel with the 9 bolt BW rear as in my info@ left states. I plan on relocating my battery over the rear where the spare used to reside. I have removed the A/C and plan on lightning the front end as much as possible as $ provides(aluminum parts to replace iron, tubular front end, etc.). I just thought the 285/60/16 might be a nice change visually and wondered if anyone had tried it. Not sure if it would hit my inner fender. I love the look of my stock 16's. I even contimplated mini tubbing and going with 2 of the aftermarket IROC wheels, having them professionally widened by an inch or 2, and run a wider tire that way. Am I rambling?????? Sorry, Daniel U

[Daniel U]

So I went the cheaper route and had 2 new KDWS mounted in front and had the old front tires (KDWS) mounted on the rear($310 out the door). Whe my '54 truck is finished, I'll have the 255/50/16 BFG Drag radials put in the back. With these wheels I can't easily rotate my tires, so putting drags on it isn't so bad.

[1989GTATransAm]

I'll hijack the thread.

Red92RS what is a very good performance tire for the street with the 16x8" rims on my GTA? I have upped the horsepower so much now that traction is a big concern on the street. I use the MT ET Street Radials when I go to the track and hope they still hold.

Looking for rear tires only and the 255/50/16 appear to be the best size. I currently have Dunlop 245/50/ZR16's on the car now and they are not holding in the least. Thanks.

[Justin86camaro]

currently i have 86 sport coupe wheels 15x7 with 215 for the track i want to get an extra set of wheels and tires for the back only. what size will fit under the rear wheel well. i'm hopin to get a 15x 10 rim but if 15x8 is all that fits that fine. i was wanting to run the MT drag radials on the wheels. also whats the largest diameter you can fit about a 28 or 29 inch on a stock rear end?

[Red92RS]

[quote=1989GTATransAm;3208725] Red92RS what is a very good performance tire for the street with the 16x8" rims on my GTA? I have upped the horsepower so much now that traction is a big concern on the street. I use the MT ET Street Radials when I go to the track and hope they still hold. [quote]

Well, I have BFGs KDWS tires because they have really good wear compared to most performance tires and are a decent price. Now I have a built LS1 so if i get on it I roast the tires. The most popular BFG performance tire I sell is probably the GForce KDW NT( NT stands for New Tread because these have a flame like design where the TT or traditional tread looks like a normal tread design). They get outstanding wet & dry traction also, I will probably buy these after my tires wear out. By the way I am running 275/40zr17s all the way around on 17x9.5 in wheels.

[Red92RS]

Originally Posted by Justin86camaro

currently i have 86 sport coupe wheels 15x7 with 215 for the track i want to get an extra set of wheels and tires for the back only. what size will fit under the rear wheel well. i'm hopin to get a 15x 10 rim but if 15x8 is all that fits that fine. i was wanting to run the MT drag radials on the wheels. also whats the largest diameter you can fit about a 28 or 29 inch on a stock rear end?

I would think unless u have a high hp engine a 15x8 in wheel would be fine. You could probably go with a 275/60R15 drag radial. Everybody should know that if you put a taller tire on the rear of your vehicle on a street driven car it will cause your speedometer to read incorrectly and that could lead to an unexpected speeding ticket, but for the track obviously it wouldn't matter because it only matters how fast you were going on your time slip. If you want to fill up your wheel well I would suggest lowering the vehicle, I have Eibach's Prokit and believe it looks alot better than stock.

[1989GTATransAm]

Yep, that is my problem. I'm roasting the tires big time. So much so that it is now a safety factor. So you recomend the GForce KDW NT tires. Thanks I will give them a good look and most likely go with them. Hopefully they have the 255/50/16 versions. Thank you for the information.

[Red92RS]

I don't see them in that size, only a 245/50R16
http://www.bfgoodrichtires.com/specs...-a-kdw/22.html

[coolram62]

I went with Sumitomo HTR-H4 235/55HR-16 on 16x8 IROC wheels on my '83 Z28.It's the same size that came on IROC and then Z28 convertibles.MY CFI 305 doesn't give me a real problem with traction off the line but they do provide excellent responce.These are all season tires but I don't drive her in the rain so i can't attest to wet traction.

[ZONES89RS]

I have seen 295/50/16, tiiiiiiight fit, looked great, dont know how it rode, my 295/50/15 fit and ride geat on my 8.5 wide wheel.

[1989GTATransAm]

The 245/50R16 tire may be the way I go. The GForce tire looks pretty good. With a 300 rating it might well do the trick.

The 295/50R16 tires may be a little to much. From what I have read the fender wells would need some work. I don't want to do that. Thanks guys.

[Justin86camaro]

Originally Posted by Red92RS

I would think unless u have a high hp engine a 15x8 in wheel would be fine. You could probably go with a 275/60R15 drag radial. Everybody should know that if you put a taller tire on the rear of your vehicle on a street driven car it will cause your speedometer to read incorrectly and that could lead to an unexpected speeding ticket, but for the track obviously it wouldn't matter because it only matters how fast you were going on your time slip. If you want to fill up your wheel well I would suggest lowering the vehicle, I have Eibach's Prokit and believe it looks alot better than stock.

so if i buy an 15x8 rim what would you reccomend the offset to be? the rims now are 15x7 with a 4.5 inch offset maybe 5 inch or something?

[Daniel U]

There's a good article in Chevy High Performaance this month on "Drag tire Tips" for those interested in learning a bit.

[DartByU]

Just put 295/50-16's on the back of my 92 equipped with stock 16" wheels and thin stock rear spacers, just had a minor amount of rubbing that was quickly fixed with a few blows of a rubber hammer, I'm not getting any rubbing at all now even during hard turning. I enclosed a few pics of where it was rubbing and the car fitted with the tires.

[Daniel U]

Who makes the tire? What speed rating do they have?

[DartByU]

Originally Posted by Daniel U

Who makes the tire? What speed rating do they have?

Cooper Cobra Radial GT, the front 235/55-16's have a T rating and the rear 295/50-16's only have a S speed rating, that's faster than I intend to go.

[92RS702]

Man that's the widest tire I've seen anyone put on stock 16s.Do they rub on bumps at all?Not on the sides but on top.

[DartByU]

Originally Posted by 92RS702

Man that's the widest tire I've seen anyone put on stock 16s.Do they rub on bumps at all?Not on the sides but on top.

I've had no problems yet, but stuff a few fat chicks in the back and you may have a problem
I might roll the wheel well for more clearance if needed. Check the pic out, seems to be enough room to me.

[83 Crossfire TA]

There’s a few people out there that have run that size successfully. With stock backspacing rear 16’s they should fit pretty well, I tried a set on some 1/4” offset TT2’s (which puts them out almost ½” further) and I was worried that they would hit a little forward and rearward of the centerline on the outside fender lip, but I didn’t really have any problems, and this was on my formula with eibach springs on it.

[83 Crossfire TA]

I found a couple of pictures...