A spring rate's influence on the setup is dictated by the installation method. In a Formula car, we see a similar situation in that there is a motion ratio. The wheel rate is much different than the spring rate. In this installation, a push rod extends from the lower control arm to a rocker arm that is connected to the coilover spring. The spring moves much less distance for every movement of the push rod, which is at an extreme angle to the control arm. In a Stock Car there are motion ratios too.