A great place to start would be the original spring rate - which is calculable with just 4 numbers: Wire Diameter, Outer spring diameter, Free length, and the Number of active coils. Make sure you use the right units of measure, and give it a go with this on-line calculator I quickly found: http://www.acxesspring.com/spring-stiffness-calculator.html

Unless there is a strong reason to change the spring rate from the original (ie, suspension bottoms out, too much suspension travel for some reason (perhaps bad geometry you want to avoid) or you want to increase carry capacity or roll stiffness at that end of the car, there should be no reason to mess with the OEM spring rates if they generally work well.


Last edited by truckin-on; 04/01/17 03:14 PM.