I am looking at replacing the springs on my vehicle and am trying to get stiffer springs while avoiding a major change in ride height.
With my vehicle, one of the old common ways to do this was to install springs from a special edition (88SS) of the car (either junkyard pull or order OEM). These springs are now super rare and I am considering getting a set custom made.
I have the Wire Diameter, Coil Diameter, Free Length and Spring Constant of both my original springs and the 88SS springs.
What I'm trying to figure out is, given a certain amount of applied weight, what the height of the spring will be so I can compare the specs of the two springs and see how much of a difference in compressed height there will be.
I'll provide the specs below if you'd like to answer with the actual numbers (please show your work though), or the formula itself.
OEM Springs (F/R)
Wire Diameter: 13.8 mm / 13.8 mm
Coil Diameter: 170 mm / 110.0 mm
Free Length: 294.5 mm / 336.5 mm
Spring Constant: 146 lb/in / 188.2 lb/in
88SS Springs (F/R)
Wire Diameter: 14.5 mm / 13.5 mm
Coil Diameter: 170 mm / 110.0 mm
Free Length: 263 mm / 317.0 mm
Spring Constant: 207 lb/in / 224 lb/in
1984 Nissan 300ZX Turbo 50th Anniversary
Gross Vehicle Weight: 3,490 lbs
Gross Front Axle Weight: 1,630 lbs
Gross Rear Axle Weight: 1,860 lbs
(Side Note: the front weight is down about 60lbs from removal of the A/C and probably a good 5-10lbs from replacing the OEM air box with a K&N filter)
Spring Specifications courtesy of http://www.az-zbum.com/information.springs.shtml