EXP. Lets look at how to change a spring and determine the rate and number of turns it is going to take to get where you want.
Wheel load: 375 on RR with a 150 pound spring.
Current spring height in car with no driver: 10.500" tall or 2.500" compressed.
Here we are going from a 150 spring to a 250 spring and will determine number of turn
need in a coil kit to make spring change and maintain ride height.
Load/spring rate = compressed height of spring.
Exp. 375 load / 150 spring rate = 2.5" of spring compression (spring in car)
375 / 250 = 1.500" (new spring) old spring - new spring = height change
2.500 - 1.500 = 1.00" / 8 turns per inch =.125 In this case it would be 8 turns.