Georgia Fiero Club Forum

All Things Fiero => Tech Tips, Tech Questions => Topic started by: jeffwilson34 on September 21, 2015, 02:35:45 am

Title: wider rear tires
Post by: jeffwilson34 on September 21, 2015, 02:35:45 am

Anyone know what the widest rear tires I can fit without making any mods to the car?
I would like to use 18" wheels and low profile tires.  maybe 17's on the front but not as wide.
The 86GT I bought with the LX9 engine will not hook up with the stock tires.  All I do is burn the rubber off sitting still if I try an aggressive start, gets sideways going to 2nd and barks them in 3rd.

It is geared too low really.  I may have to try and find something with a much higher gear.  Right now it is redlined at 8000RPM at around 120MPH   My 4cyl SE has a higher top end speed.

Title: Re: wider rear tires
Post by: Fierofool on September 21, 2015, 12:06:11 pm

Joe Torma on Pennocks had a very comprehensive chart but all the links to it have disappeared.  If you're on PFF, you might
pm him for a copy.  You do have to be careful on the early models without coilovers.  My brother's 86 has 17-s with low profiles and he had to put spacers to end up with about 1/8 inch clearance between the sidewall and the spring boss.  Spacers wouldn't be recommended for your horsepower application. 

I'm running 245/40-17's on the rear of my 86 and there is less than 1/4 inch clearance with stock 35mm offset.  225/45-17's on the front, stock 35mm offset and they don't scrub the fenderwells. 

I found another thread and RCR posted a PIP image of the links.  Maybe this will help.
http://www.fiero.nl/forum/Forum1/HTML/058236.html

Title: Re: wider rear tires
Post by: jeffwilson34 on September 23, 2015, 02:15:41 am

looks like I will end up getting a set of coilovers.
Anyone know the best place to get them.   
I have a set of corvette wheels but the bolt pattern is not the same.
Looks like I will be getting a set of wheels and tires.
I would like something on the rear as wide as possible but want to keep the front a couple inches narrower
I want to stagger the wheel size also with 18s on the rear and 17s on the front.

Title: Re: wider rear tires
Post by: Fierofool on September 23, 2015, 09:17:44 am

Yesterday I received a new sales paper from Tire Rack.  They sell ST, KW, Bilstein, Koni and KYB.  Summit Racing also sells coilovers and wheels. 

Title: Re: wider rear tires
Post by: jeffwilson34 on September 23, 2015, 01:04:24 pm

thank you for the info
I will check on prices and see what I can afford at the moment

Title: Re: wider rear tires
Post by: Raydar on September 23, 2015, 09:29:42 pm

I posted about "traction" in the other thread, but I'll go over it a bit here.
I have 17x8 wheels with a 35 offset on the rear of mine. My rear tires are 235/45-17s. (They will also fit on an earlier car, even with stock springs / perches. I had a similar set on my 84, for a while, while I had it.) I have had 245/45s on it, for a period... 
Even the 235s seem to be plenty of tire for my car and engine, and the way I drive it. But they're fairly soft. Treadwear is ~280.