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Old 11-19-2013, 12:26 PM   #8 (permalink)
GSS138
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Join Date: Mar 2013
Location: Mission Viejo, CA
Posts: 769
Drives: '12 370Z 6M Sport
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It's easy to measure yeah did it myself.

Just take the length where the shock attaches to the lower arm, then divide that by the total length of the arm. There is also a correction factor that you have to make based on the shock angle from 90 degrees straight up from the lower arm. However our shock is somewhere around 80 degrees(10 degrees off of perpendicular) so the correction factor is really negligible.

I can't remember the exact lengths but the result is ~.61-.65. In our case this is the motion ratio of the spring and the shock. Since they are connected at the same places and are perfectly parallel.

Compare the front to the rear, and the rear spring perch is much further up the control arm(9"/18"- I remember this one). On the rear, our spring has a .50 motion ratio-that is why the rears have stiffer springs, car is lighter, yet the rear wheels have lower wheel rates(makes them softer). Basically the rear wheel has a very large mechanical advantage over its spring.
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