spring rates (Page 2/2)
fieroguru NOV 23, 07:57 PM
Have you calculated the natural frequency for the front and rear suspension? Generally speaking you want the rear to be 0.1 to 0.3 Hz higher than the front, and the range can be from .8 Hz for a daily driver to 2.2 to 2.5 for a dedicated autocrosser.

So you might want to measure what you have currently and verify the rear is slightly higher and where in the spectrum your spring rates put your combo.

There are lots of individual adjustments to bias oversteer/understeer but these are to fine tune. To effectively use them, you need the baseline setup in range.

I find a lot of the information on this website helpful.
http://farnorthracing.com/autocross_secrets5.html

If you need them, Blooze did a great job of detailing the 88 front and rear suspensions with the dimensions for the key suspension component locations at stock ride height. I have a copy... somewhere. They help give you a starting point, but then as you lower the car, change pivot locations and increase static camber, it helps to draw everything in a cad package to get the new coordinate data.

[This message has been edited by fieroguru (edited 11-23-2016).]

wftb NOV 23, 11:13 PM
Bloozeberry's awesome drawings are still in his thread in the construction zone .He went away , sad ,but at least he left all his posts here .If you have not visited his thread , it is an eye opener .

[This message has been edited by wftb (edited 11-24-2016).]

hardrock2112 AUG 03, 08:25 AM
Hello,
I am a total newbie, and reading a LOT of posts to get an understanding of the suspension. Earlier in this thread someone said:



quote
"Stock spring rates for an 88 Fiero are 205 lb/in front, 147 lb/in rear."




I'm asking myself, shouldn't the rear springs be stiffer than the front since the rear weighs more?

Thanks in advance!
Hardrockin Old Guy
Blacktree AUG 03, 05:10 PM
Your question was answered already. Read Fieroguru's posts.
fieroguru AUG 03, 07:22 PM
It is the difference between a-arm suspension with the springs mounted halfway between the bushings and ball joints vs. a strut suspension with the springs pretty much on top of the tire. Even with the stock springs, the actual wheel rates are about 2.5 times less in front than rear, which more than takes care of the additional rear weight bias.


quote
Originally posted by fieroguru:
Stock spring rates for an 88 Fiero are 205 lb/in front, 147 lb/in rear. The motion ratios are about .5 front and .97 rear.

So the effective spring rate at the wheels are:
Front = 205 x 0.52 = 51.25
Rear = 147 x 0.972 = 138.31 (255% higher than front).

[This message has been edited by fieroguru (edited 08-04-2022).]

fieroguru AUG 04, 07:01 AM
If your car is riding rough, first thing to do is use a camera/cell phone and see where the bump stops are to their stop for front and rear suspensions. Many people lower the car w/o addressing the bump stops and end up riding on the bump stops vs. springs which makes for a very stiff/bouncy ride.

[This message has been edited by fieroguru (edited 08-04-2022).]