The SERIOUS Wheel & Tire Thread

[The Dark Side of Will]

Sorry for the threadjack, this is more of a moderate tire setup versus a SERIOUS setup

We won't make you start The MIDDLING Wheel & Tire Thread.

[pmbrunelle]

What is your target suspension frequency?

Well as described above, I was thinking more in terms of the minimum stiffness needed to stay off the bumpstops, given a certain load (which was the big mystery). So the frequency would have been a consequence, not a target I was shooting for. I was not prioritizing the reaction time of the car to my inputs.

So from what I know of the Moogs (guesstimated front ride frequency of 1.65 Hz), I would most likely need 325 lb/in rear springs to "match" the front with a 15% higher rear ride frequency.

However, I will wait until the Moogs are on the car before I attempt to get a matching rear spring.

Sometimes it's not always clear in my head what kind of modified car project I want to have, so I can inefficiently bounce between paths/ideas before I converge on something. For now, the project direction is kind of defined because of the Moogs I was able to find on Rockauto...

[draven]

Totally understand bouncing around and having to go with something ballpark, i.e. the moog fronts and then designing from there given the limited spring selection with the front suspension, pre 88 AND 88's and not relying on a "kit" that someone else thinks is the best setup....i.e. steven snyder's endeavors. 1.65hz is very respectable and should be a nice compromise as long as the suspension travel is maintained... Speaking of suspension travel, are you going with a rear 88 cradle or sticking with the pre88?

it's been a minor PITA to get coil overs on the 88 front to get 2.5" springs without going mustang II conical and maintain as many stock parts as possible. Have two koni solutions I'll be going over in my build thread. I'll bow out with further suspension questions as to not cloud this thread...

[pmbrunelle]

1.65hz is very respectable and should be a nice compromise as long as the suspension travel is maintained... Speaking of suspension travel, are you going with a rear 88 cradle or sticking with the pre88?

I'm planning on having my Fiero at a stock-ish ride height. Not a trendy look per the hellaflush/stance crew, but staying off the bumpstops is always in.

Actually, I have a friend who offered me his spare 88 cradle, but for now my longer-term project goal is to roll my own A-arms (with different pivot points) for the pre-88 cradle. More unique/fun than bolting in GM's design. Also, I already have a good brake setup for the pre-88 knuckles, so I'd like to be able to use those brakes as-is.

[Series8217]

Now running 315/30/18 rear and 265/35/18 fronts on my 88. The tires are Nankang CR-S (200tw).

The wheels are Apex SM-10 18x9.5 ET35 and 18x11 ET35. I'm running a small (3 or 5mm) spacer in the rear to clear the trailing link, which is lowered by 45mm at the upright compared to the stock. Otherwise my hub-to-hub distance front and rear is within a few mm of stock.

fiero-265f-315r-apex-sm10.png (1.31 MiB) Viewed 311 times

Obviously this is quite an aggressive fitment. With ~800lb/in front springs and 500 lb/in rear springs I had to add taller bumpstops and set the ride height nearer stock to keep the tires off the fenders. The extra height is to get me by until I cut the wheel openings and add flares. It has been working mostly.. until I hit a big sharp dip on a road while flat on the gas in first and the rear left tire impacted and cracked the rear clip. In autocross I haven't had any issues. Just the severe bump on the street.

In front, the first point of interference is actually the fender liner. If that were removed I think I'd be OK with my current springs and bumpstops. There are no issues with turning fully lock to lock.

Grip is of course bananas.

[eHoward]

Looks good!

Those tires are pretty impressive in the dry: https://www.tirerack.com/tires/tests/ch ... p?ttid=315

[NoGoodFiero]

Now running 315/30/18 rear and 265/35/18 fronts on my 88. The tires are Nankang CR-S (200tw).

Haha!!! Looks awesome!!. Any static pictures?

edit: Is your track width still stock with all the suspension mods?

[The Dark Side of Will]

Now running 315/30/18 rear and 265/35/18 fronts on my 88. The tires are Nankang CR-S (200tw).

The wheels are Apex SM-10 18x9.5 ET35 and 18x11 ET35. I'm running a small (3 or 5mm) spacer in the rear to clear the trailing link, which is lowered by 45mm at the upright compared to the stock. Otherwise my hub-to-hub distance front and rear is within a few mm of stock.

fiero-265f-315r-apex-sm10.png

Obviously this is quite an aggressive fitment. With ~800lb/in front springs and 500 lb/in rear springs I had to add taller bumpstops and set the ride height nearer stock to keep the tires off the fenders. The extra height is to get me by until I cut the wheel openings and add flares. It has been working mostly.. until I hit a big sharp dip on a road while flat on the gas in first and the rear left tire impacted and cracked the rear clip. In autocross I haven't had any issues. Just the severe bump on the street.

In front, the first point of interference is actually the fender liner. If that were removed I think I'd be OK with my current springs and bumpstops. There are no issues with turning fully lock to lock.

Grip is of course bananas.

Awesomesauce that you got it up and running with those!
Do you still have Koni rear struts?

How much wheel-to-strut clearance do you have? I have C5 Corvette 18x9.5-61 rear wheels with 25mm adapter. Based on that fitment, an 18x9.5-35 would work with no spacer/adapter. Interesting that you fit an 18x11-35 and it still cleared the strut.

[Series8217]

Awesomesauce that you got it up and running with those!
Do you still have Koni rear struts?

Yeah still running underdamped Koni reds set to full stiff

How much wheel-to-strut clearance do you have? I have C5 Corvette 18x9.5-61 rear wheels with 25mm adapter. Based on that fitment, an 18x9.5-35 would work with no spacer/adapter. Interesting that you fit an 18x11-35 and it still cleared the strut.

There's enough. I didn't measure clearance to the strut because the trailing link hit first.

Remember I don't have Fiero uprights anymore, so you can't really compare to a stock Fiero.

Screenshot 2024-04-25 at 6.50.41 PM.png (51.42 KiB) Viewed 128 times

[The Dark Side of Will]

I didn't know you moved the strut connection on your hub carriers