Best tire setup for 87 GT (Stock Wheels) (Page 2/3)
Kevin87FieroGT MAY 07, 09:55 AM
Hey Joe,

Thanks. Getting time to retire Bob’s T/A’s.
Skybax MAY 07, 10:12 AM

quote
Originally posted by AmphotEric:

the only negative I see is the lack of options + impact on my wallet.



While the negative effects are minimal, you can't simply discard them.

If going from 215/60 to 225/60 in the rear it will certainly change the following...

- 1/2" taller overall diameter
- Speedo read slightly higher
- Heavier in weight
- More rotating mass
- Final drive ratio will change from 3.65 to 3.58 (more highway gear)

When you combine added weight of all 4 plus-sized tires with increased highway gear, the stock 2.8 V6 will accelerate noticeably slower.

Will it handle slightly better? Maybe, depends on the tire, but at a cost of all the above. Doesn't seem worth it to me, but some people like bigger tires.

Re-read my first post, you will have better results going with stock size H-Rated tires that have softer compound (better grip) without sacrificing performance.

PS: After thinking about it some more, I think Radial T/A and Tiger Paw in those sizes are both T-Rated, so a slighter larger/taller 225/60 T-Rated tire in the rear might handle worse than a stock 215/60 H-Rated tire (despite the slightly wider contact patch) because the T-Rated sidewall will be taller and softer, resulting in more mush-rollout, so it might be a downgrade across the board (reduced handling and reduced performance) but you would have to talk to the Watkins Glen road course experts about the handling part.

[This message has been edited by Skybax (edited 05-07-2022).]

olejoedad MAY 07, 11:23 AM
I ran stock sized tires for years on 15" lace wheels.
One of the best things I ever did for my 85 GT and 86 SE was to switch over to 215/225 combo.
This is after running lace wheels on both cars for quite some time.
AmphotEric MAY 07, 03:30 PM

quote
Originally posted by Skybax:


While the negative effects are minimal, you can't simply discard them.

If going from 215/60 to 225/60 in the rear it will certainly change the following...

- 1/2" taller overall diameter
- Speedo read slightly higher
- Heavier in weight
- More rotating mass
- Final drive ratio will change from 3.65 to 3.58 (more highway gear)

When you combine added weight of all 4 plus-sized tires with increased highway gear, the stock 2.8 V6 will accelerate noticeably slower.

Will it handle slightly better? Maybe, depends on the tire, but at a cost of all the above. Doesn't seem worth it to me, but some people like bigger tires.

Re-read my first post, you will have better results going with stock size H-Rated tires that have softer compound (better grip) without sacrificing performance.

PS: After thinking about it some more, I think Radial T/A and Tiger Paw in those sizes are both T-Rated, so a slighter larger/taller 225/60 T-Rated tire in the rear might handle worse than a stock 215/60 H-Rated tire (despite the slightly wider contact patch) because the T-Rated sidewall will be taller and softer, resulting in more mush-rollout, so it might be a downgrade across the board (reduced handling and reduced performance) but you would have to talk to the Watkins Glen road course experts about the handling part.




I actually never really considered weight or gear ratios.

I'm honestly really torn. I live in an area with lots of mountains and twisty roads, so I think handling is my main priority, especially when I consider safety.

Could I circumvent the additional weight & get the best of both worlds (more contact and softer sidewall) by going 225 + 215 by running a 50 aspect ratio vs 60? Do people do this, or is a wider sidewall better for the aesthetics of the car?
AmphotEric MAY 07, 03:33 PM

quote
Originally posted by olejoedad:

I ran stock sized tires for years on 15" lace wheels.
One of the best things I ever did for my 85 GT and 86 SE was to switch over to 215/225 combo.
This is after running lace wheels on both cars for quite some time.



Did you notice a big increase in performance/handling or a decrease in speed or Acceleration as mentioned above?
olejoedad MAY 07, 05:43 PM

quote
Originally posted by AmphotEric:


Did you notice a big increase in performance/handling or a decrease in speed or Acceleration as mentioned above?



Not a bit of performance loss that was discernable, but the handling was greatly improved.
And you want stiffer sidewalls, not softer.

'H' rated tires are the ticket.

I would stay away from 50 series tires, the Fiero likes some sidewall. And the car looks a lot better.
AmphotEric MAY 07, 05:52 PM

quote
Originally posted by olejoedad:


Not a bit of performance loss that was discernable, but the handling was greatly improved.
And you want stiffer sidewalls, not softer.

'H' rated tires are the ticket.

I would stay away from 50 series tires, the Fiero likes some sidewall. And the car looks a lot better.



What is your reasoning for the H-rated? Same as Sky's above?

What tires are you running currently?

[This message has been edited by AmphotEric (edited 05-07-2022).]

olejoedad MAY 07, 06:44 PM

quote
Originally posted by AmphotEric:


What is your reasoning for the H-rated? Same as Sky's above?

What tires are you running currently?




Experience - I've daily driven a Fiero for decades, year around. Driven them hard, have spend a lot of time in the Tennessee/North Carolina area running mountain roads. 'T' rated tires don't handle ery well as compared to 'H' rated tires. I've used different several brands over the years, the stiffer sidewalls allows crisper turn-in and more control at the limit of adhesion.

The 15" tires right now are two different brands - fronts are OHTSU FP6000 215/60/15.
Its the same tire as the Falkan 512 (OHTSU makes Falkan) which were very good handling tires but weren't available.
The rears are 225/60/15 FUZION Touring, as I needed tires and they were the only thing available in 'H' rating without waiting. They aren't bad tires, I was surprised.
Both front and rear are 'H' rated.

The car (88 Formula 4.9 V8/4T60E) has run the Dragon several times with these tires.
You won't catch me.

The biggest thing to making a Fiero handle well is seat time. I've logged over 250,000 miles in the Fieros I've owned (85 GT stock 4-speed - 86 SE V6/4 speed stock for a while, then a bunch of suspension/brake/sway bar work, now the Formula) so I know what the car is capable of.
If you're just a weekend driver, you will never find out what the car can do.
AmphotEric MAY 07, 06:59 PM

quote
Originally posted by olejoedad:


Experience - I've daily driven a Fiero for decades, year around. Driven them hard, have spend a lot of time in the Tennessee/North Carolina area running mountain roads. 'T' rated tires don't handle ery well as compared to 'H' rated tires. I've used different several brands over the years, the stiffer sidewalls allows crisper turn-in and more control at the limit of adhesion.

The 15" tires right now are two different brands - fronts are OHTSU FP6000 215/60/15.
Its the same tire as the Falkan 512 (OHTSU makes Falkan) which were very good handling tires but weren't available.
The rears are 225/60/15 FUZION Touring, as I needed tires and they were the only thing available in 'H' rating without waiting. They aren't bad tires, I was surprised.
Both front and rear are 'H' rated.

The car (88 Formula 4.9 V8/4T60E) has run the Dragon several times with these tires.
You won't catch me.

The biggest thing to making a Fiero handle well is seat time. I've logged over 250,000 miles in the Fieros I've owned (85 GT stock 4-speed - 86 SE V6/4 speed stock for a while, then a bunch of suspension/brake/sway bar work, now the Formula) so I know what the car is capable of.
If you're just a weekend driver, you will never find out what the car can do.




Is the reason you're running different fronts and backs because the Ohtsu's aren't available in 225? I honestly can't find any tire options in the 225/60 + 215/60 aside from Tiger Paws and Radial TAs (which I believe are S rated, but I'm Actually unsure. Do you know?).

My options have been very limited. Tire Rack, Canadian Tire, 1010 Tires, etc all have the same options, or none at all. It really seems like I'm stuck going with the Radials.
cvxjet MAY 07, 07:16 PM
Just checked on Tirerack; They have the Riken Raptor HR in the original 205/60 and 215/60 sizes for a total of $380. You can have them delivered to a local shop- usually Big O. Do not go with BFG Radial TA- back in the 70s and 80s they were a great tire- but now they are for the car show guys who don't do much driving and don't care about performance.

The other good option is the General Altimax RT43....They are lighter (Which will improve performance)- but they are also more expensive by $80