How do you tel what rear springs you have? Options

[Tdskip]

Time to educate myself on the rear suspension, it seems that the rear springs and shocks have quite a bit of options. Also seems that rear springs are the way to lower the car (seems obvious when I type that) and will have a big impact on ride stiffness.

Is there a way to tell what spring you have, maybe starting with ride height? Are the springs unique colors (common on Alfa’s) to make identification easier?

Thanks!

[barefoot]

Easier way:
Calculate the spring rate from a few dimensions you can make, then use the link:

https://www.acxesspring.com/english/compres...lculations.html

I measured my spare set (assembled), so free length is a guess, but spring rate not affected.
Wire diameter = .387"
Coil OD = 4.1"
Number of coils = 10
Free length = 15

That yielded a rate of 62 Lb/inch

[Mark Henry]

Easier way:
Calculate the spring rate from a few dimensions you can make, then use the link:

https://www.acxesspring.com/english/compres...lculations.html

I measured my spare set (assembled), so free length is a guess, but spring rate not affected.
Wire diameter = .387"
Coil OD = 4.1"
Number of coils = 10
Free length = 15

That yielded a rate of 62 Lb/inch

I just used the calculator for my set of unknown springs and a set of Weltmeister SP100 100 lbs springs.

Specs unknown springs from the late 80's/early 90's bought at AA IIRC.
Wire diameter = .475"
Coil OD = 4.125"
Number active of coils = 9
Free length = 12.5"

= 160 lbs (159.5)

Specs Weltmeister SP100 (100 lbs), springs are about 4 years old.

Wire diameter = .425"
Coil OD = 4.250"
Number active of coils = 7
Free length = 15"

= 120 lbs (119.64 lbs)

So either the calculator is wrong or Weltmeister SP100 advertised as 100 lbs are actually 120 lbs springs.
My unknown springs 160 lbs sounds about right.