My 1988 LFX F40 build. (Page 31/68)
fieroguru APR 03, 08:07 PM
That is a htob spacer.
mender APR 07, 12:02 AM

quote
Originally posted by Daryl M:



Finally finished the rear sway bar. I used a torsion bar from a 1989 Isuzu Trooper. Total cost came to about $65.


Do you know what the bar diameter that you used is?

Hard to believe that I started my LFX swap four years ago! I guess I'd better finish it soon!

[This message has been edited by mender (edited 04-07-2020).]

Daryl M APR 07, 03:43 AM
I believe the torsion bar I used was from a 1989 Isuzu Trooper and was 1.1 inches, but I am just going by memory. I'll go measure it when I get time and get back to you with the specs.
mender APR 07, 10:58 AM
Also measure the length of the centre section of the bar and the effective lengths of your arms.
Daryl M APR 07, 11:30 AM
Mender, the specs are as follows:
Length. 38"
Arm length. 9.5"
Diameter. .990"
Mounts are 31" apart.
Is that what you wanted?
mender APR 07, 06:51 PM
Yes. What are you using for a front sway bar? Springs?
Daryl M APR 08, 10:34 PM
As for the front suspension, I haven't done it yet.
mender APR 10, 10:58 AM
Your rear bar works out to 291.2 lbs/in, which is a lot when you consider that it is also the wheel rate (connected directly to the struts). The stock 88 GT rear bar that also attached directly to the rear struts works out to 92.4 lbs/in. You have effectively tripled your rear sway bar wheel rate.

You'll either need to attach it to the rear control arms instead to substantially reduce the wheel rate or get a rather large front sway bar to balance it.

I would have to do some measuring but I think my 1.25" rear bar has a much lower wheel rate because of where it attaches to the lower control arms ('85 rear suspension). One of the upgrades that I'll be doing is to convert to the strut mounted links and make my rear sway bar adjustable. I'll be aiming for about the same range as my present rear bar.

My Herb Adams rear bar is pretty heavy and non-adjustable.

[This message has been edited by mender (edited 04-10-2020).]

Daryl M APR 10, 12:45 PM
Mender, you are obviously more informed than I am about this issue. My 88 did not have a sway bar from the factory. What would you expect the addition of my sway bar to be? What should I expect if no other suspension changes are made?
mender APR 10, 02:56 PM
The result will be massive oversteer. You'll spend as much time looking through the side windows as you do the windshield.

I hate to say this, but my advice is to unhook it at the very least for now. You'll need quite a big front bar to balance that one, and I doubt there's one available. Best would be to find either stock GT bars or a matched aftermarket set and install those, then play with springs.

Just went to my shop and measured things, your rear sway bar is equal to a 1.35" rear sway bar on an '84-'87 rear suspension. That's huge, considering the Herb Adams rear bar is 1.25".

Edit again: have a look at this thread:
http://www.fiero.nl/forum/Forum4/HTML/043365.html

Your rear bar is just under 300 lbs/in, putting it close to the top of his performance bar and the bottom of his competition bar. Looks like his performance front bar would work with your rear bar. Not cheap though and he quit making them 5 years ago. Still might be worth a check.

[This message has been edited by mender (edited 04-10-2020).]