Rear wheel rate vs spring rate

[TobyB]

Gustave says it's .45

http://www.e30m3project.com/e30m3performance/tech_articles/susp-tech/eff_rate/eff_rate2.htm

which seems a little low based on the real numbers I got from some stock car
parts I used. But not out of the realm of believability- calculating the
real rate of a 5" spring compressed in a vee is not trivial. Nor linear, it seems.

Anyone here have real- world numbers they'd be willing to share?

Mine: 600# 5" dia by 5 1/2" long spring gave a rate of 300# per inch at the wheel, measured with scales and a tape measure. 200# preload, 7" to 6" rocker height.

(yes, I tried to search, but failed.)

t

[TobyB]

Huh. It's not linear. At all. A shorter, stiffer (by about #50) spring had a #50 softer
wheel rate. Looks like quick and dirty isn't going to work... but I hate having to get methodical...

t

[Jean]

How did you measure?

[bmwguy325is]

I paid someone to set up my car. 5 inch spring 750#
This may help you

http://www.racingaspirations.com/?p=292

[TobyB]

How did you measure?

with a jack under the wheel, and scales under the jack. The springs are by math only-
but they're Eibach, and 'should' obey reason...

t