88GT Road Race car build with a 3.4TDC (Page 10/18)
Frenchrafe SEP 14, 07:06 PM
Yeah, I know how you feel.
Mine is kind of wavey at high speed - very white knuckle inducing!๐Ÿ˜ต

I set my front suspension with more camber than the rear. This gives good control in cornering. Nice and tight.
However, the straights are a bit more trickey to hold.

I'm not sure the aero plays in below 150 to 160km/h, but above it will tend to lighten the front.

Again, my car gets jacked up on the rear when tackling a fast track. You don't win the shoe test for the lack of wheel/fender clearance, but you do keep the front more predictable heading towards 200km/h!๐Ÿ˜

For your bolt issues, try largeur washers.
If no good then washer with small piece of threaded bar welded to the washer. A fixed stop welded to the arm and then lock nuts to block the washer at a set distance. The threaded bar passes through the stop.
(Similar to how the rear wheel on a motorcycle is blocked for chain tension and centering.)
Alot of fabrication though๐Ÿ˜Ÿ

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. Sticky tyres. Driven hard!
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

[This message has been edited by Frenchrafe (edited 09-14-2020).]

darkhorizon SEP 14, 08:31 PM

quote
Originally posted by Will:

How much caster are you running?



I was struggling to get a good reading, but a ton, like 6-8 degrees. I try to set it up about the same as my s2000. I do notice that in parking lots it likes to push badly at high steering angles as well, which suggests that I have a bunch I believe.
La fiera SEP 14, 09:27 PM
The wondering under hard braking in my case went away when I drove it at the track with the welded differential.
Before, even letting off the gas the car started to wonder at high speeds. Even trail braking was very predictable with the welded diff.
That's why I invested in a real diff. Will warned me but like a kid I had to burn my fingers to find out the water was hot!
FieroWannaBe SEP 15, 08:42 AM
Triple check the rack body.
I've seen a few from the great north that form corrosion and cracking near the mount under the rubber.
Will SEP 15, 09:23 AM

quote
Originally posted by darkhorizon:

I was struggling to get a good reading, but a ton, like 6-8 degrees. I try to set it up about the same as my s2000. I do notice that in parking lots it likes to push badly at high steering angles as well, which suggests that I have a bunch I believe.



The shop manual says 5.5 degrees for the GT & Formula with less for the 4 cylinder. As you get more caster, you raise the outer tie rod end out of its bumpsteer sweet spot. You may want to do a bump steer sweep on the suspension.

I'm also about to test fully adjustable upper control arms for my Formula.

I assume you've tried the 3-9 and 12-6 shake tests on each wheel.
Rickady88GT SEP 15, 01:45 PM

quote
Originally posted by FieroWannaBe:

Triple check the rack body.
I've seen a few from the great north that form corrosion and cracking near the mount under the rubber.



Just a simple question, because I have never "raced": should the rack have rubber mounting? Is poly a better option or even solid?
darkhorizon SEP 16, 08:10 AM

quote
Originally posted by La fiera:

The wondering under hard braking in my case went away when I drove it at the track with the welded differential.
Before, even letting off the gas the car started to wonder at high speeds. Even trail braking was very predictable with the welded diff.
That's why I invested in a real diff. Will warned me but like a kid I had to burn my fingers to find out the water was hot!



I expect the phantom slip has given up the "ghost" already, but it technically is a little limited in the amount of slip it has. I absolutely am not ready to trail brake but some more brake bleeding and balancing will hopefully fix that soon, although I honestly dont need to trail brake at all when I get into a more "gokart" style driving habit with this car as I can always lay big power out and flick in with quick easy rotation the way its setup now.


quote
Triple check the rack body.p



I really have big doubts here. I have a legit new old stock rack with baer ends on it (one is pretty beat up and loose, but im talking a very tiny amount, will be replacing it before the last track outing this year). I will look around and probably machine up some sort of billet mounts for the rack soon.


quote
You may want to do a bump steer sweep on the suspension.



With almost no travel left in the suspension thanks to my heavy front springs and bar, i really cant imagine I get much here. However I would like to increase my droop height somehow, i really think these QA1 shocks are just a little short for what I'm doing. My front tie rod is just slightly under parallel at ride height so I cant imagine another less than 2 inches of suspension movement at the wheel is going to cause much here. The droop increase will let me gain a tiny bit less understeer out of corners due to the roll I'm building into the rear of the car over what the previous owner had. I really have the balance setup super neutral now that the alignment is coming up to my standards.


quote

I assume you've tried the 3-9 and 12-6 shake tests on each wheel.



And the results were "bad" but honestly I'm not sure how I'm ever going to get and keep a perfectly tight bearing on this car at this point. I email'd dickman and he didnt get back to me with any info on his bearings, and I'm dragging ass on doing a custom e30 M3 bearing so far.

I'm still expecting my upper control arms to come loose, so an adjustable one would be fun as I could just weld in the dog bone butteryfly nut system and run all my adjustments manually. I will be hopefully checking the old delrin bushings for failure tomorrow, but I'm really doubting they have failed considering I cant find any play in the arms by hand at all.
darkhorizon SEP 16, 12:58 PM


darkhorizon SEP 17, 10:57 AM
I'm deleting the rear scoop thing, I realized I really hate how it looks and how it functions. I am going to run some 84-esk louvers over the intake manifold.
Will SEP 17, 12:42 PM

quote
Originally posted by darkhorizon:

I'm still expecting my upper control arms to come loose, so an adjustable one would be fun as I could just weld in the dog bone butteryfly nut system and run all my adjustments manually. I will be hopefully checking the old delrin bushings for failure tomorrow, but I'm really doubting they have failed considering I cant find any play in the arms by hand at all.



Yeah, trying to keep 5x100 bearings in a Fiero race car is kind of an exercise in futility.

Adjustable control arms: http://www.realfierotech.co...php?p=159201#p159201

I should be installing these this weekend, although the car won't be back on the road for a bit.