My son has an 88 Trans Am GTA. Gen1 327sbc/th400/9 bolt. It has run low 13's @ about 100 mph with stock suspension and 2:70 gears. The 225/60r16 Goodyears are showing pretty bad weather checking on the sidewalls. We want to use the stock honeycomb wheels. Any suggestions for type and size of rear tires? I don't think the trap speed calls for front runner type tires on the front. This a track only bracket car. Thanks for any replies.

 

Being a track only car, using a street tire is a waste of money. Majority of slicks are for 15" rims. If you want to run a heavy, factory 16" rim, tire choices are very limited.

If you put some 15" times on the car, staying with the 2.7x gears, you don't want to go taller than 26".

 

Depends on what you are looking for, but a few suggestions:

3793R - Mickey Thompson 26x10.5 R16
555 R - Nitto Drag Radial

There are a few options in bias as well..

 

Thanks, we were thinking of using the stock wheels to save some money. He and his wife just had a baby. But, tire selection is kinda sparse for 16 inch rims. What is the best offset for a stock wheelwell in these cars?

 

Most third gen race cars use a 15x8 or 15x10 rim depending on the tire width. The rim width should be close to the tread width. A Race slick, the width of the tire is across the tread. A DOT tire, the width is across the section. A 10.5" DOT tire is closer to 8" of tread width while a 10.5" slick has 10.5" or tread and the width of the tire will be greater.

So technically, a 9-11" tread width should be mounted on a 10" wide rim. A 7-9" tread width should be mounted on an 8" wide rim. Factory rims are generally around 7" wide.

5.5" of backspace works well with no fender modifications.

 

Thanks for the help. Trying to get things done before racing starts.

 

Since you are trying to be as cost effective as possible, I would suggest a set of stock Z28 5 spoke aluminum wheels, wrapped in some 26 x 8.5 slicks.

 

i second the m/t 3793R. it's a 255/50/16 et street radial. hardly a "street" tire. it will work good for you.

 

Shop Craigslist or similar trading sites, Facebook has some usually area specific. Front narrow tires are more to reduce rolling resistance and diameter is according to reaction times if you footbrake. Without mods I'd say 8" rims should fit, maybe a little hammer adjustment but nothing radical. probably 4.5" back space to 5" with 9" slicks. Start saving for the rearend now.

 

Thanks for the help. He's for sure saving up for a 9 inch in the future. Are the Iroc wheels much lighter than the snowflake wheels we have now?

 

no, the gta wheel is the lightest oem wheel available on a thirdgen if im not mistaken. i would run those wheels with a 255 m/t radial.

 

I would look into the M/T drag radials. They hook hard. I don't really think that you are running the times that warrant the need for a full slick. Plus a drag radial can be used on the street.

 

How about Mickey Thompson ET Street bias ply slicks? If price is a point, there's some savings and they fit well enough on my 16" IROC rim. That might suit the OPs rim as well.








I've had the discussion on bias ply vs radial and it generally seems to be split. There are as many variables as opinions. Or is that thinking dated?

 

true stiffwall bias to a radial is about a wash. the radial is normally a little faster, but the bias is more forgiving.

the ET Street bias is not a stiffwall, and the compound is much harder than either of the radial or the true ET Drag bias for more treadwear. i don't often recommend them as they can be tough to make work.