Does anyone have a stock 84-87 front spring they can measure? How long is it, and what is the inner diameter? Is the coil the same the entire length of the sprig, or does it get thinner towards the bottom and/or top?

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1984 Fiero SE

The springs have a slight taper. The only spring information I've ever found is this chart. But spring ratings aren't given on GM's chart.
Why couldn't they include them to make things "easier"?? http://calgaryfieros.com/OSGdocs/springs.html

I have 4 sets of front springs out and put them in this calculator
http://www.proshocks.com:80/calcs/coilsprate.htm

These are the numbers for FRONT springs that I have.
I used a nominal diameter of 4.125" for all the springs (varies slightly).
Wire diameters were 12.5mm (.49213") and 13mm (.5118")
It is predominantly the number of coils that affects spring rate.

1984
CODE Length Spring/OD Wire/OD Coils = Calculated Spring Rate (lbs)
DMF 13.5" 4.125" 12.5mm 9 = 191 lbs
DMN 13" 4.125" 13mm 8.75 = 234 lbs

1985-87
FJA 14" 4.125" 12.5mm 10.5 = 164 lbs
FJH 13" 4.125 13mm 9.75 = 210 lbs

If any one else has loose springs (and Codes from RPO sheet in front compartment), we can start a database for these things. While not ideal, it may at least give some kind of reference as to different spring stiffnesses relative to each other by Code and can help those swapping stock springs around.

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World of Wheels Winners
My 3.4L S/C 87 GT
& Super Duty 4 Indy #163

[This message has been edited by fierosound (edited 11-16-2009).]