Also, the load on the spring is greater than the load on the tire from the weight of the car. The moment for the force on the tire is the distance from the pivot of the lower A-arm to the center of the tire times the sprung weight on that corner of the car. The load on the spring is the moment on the tire divided by the distance from the lower A-arm pivot to the center of the spring. The proper way to set the suspension components is set the chassis at the attitude you want it running at; set the X-member in the chassis so the lower A-arm is parallel to the ground and the center of the X-member is level with the ground. The spring rate is the last item to design after the other components are installed properly. My guess is to start with the springs from a 6-cylinder MII. The engine in an MII is way over the wheel center so the springs will be a little stronger than you might suspect. You won't really know the final ride height until you have the car completely done with all the pieces in place and the loads on the springs complete. Only then will the final ride height be known. Rather than trying to calculate it, I find it easier to get a few junk yard sets of springs and cut and try. If a set of springs gets you close but the car is a little high, an inch or so, just torch off one loop on the spring. Won't harm the ride in the slightest and will get you the inch drop you need.
Last edited by email@example.com; 03-15-2004 at 03:03 PM.