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Old 01-21-2004, 12:02 PM
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This might help, whether you're running a ladder bar, 4link, or even a 3link:

Consider a side view of the car. Imagine a vertical line drawn through the front tire patch. Then, a horizontal line through the center of gravity. These two lines intersect at a point above the front tires. Finally, consider a line drawn, from that intersection, through the rear tire patch. Detroit calls this the "no squat/no rise" line. If the rear suspension instant center (pivot point of a ladder bar or the intersection of lines through the upper and lower links of a 4link) falls anywhere on this line, the rear of the car will neither squat nor rise on acceleration. If it falls above, the rear will rise; if below, it will squat.

Since the front suspension links do not carry similar dynamic loads during launch, there exists no similar trick. In other words, the front will always rise. By using "softer" (lower rate) springs at the front, you can get the front to rise even more, of course. This raises the center of gravity very slightly and thus increases the weight transfer.

There is a little trick available at the front which will affect rear tire loading, however. By using a lower rate spring at the left front than at the right, the left front will rise more than the right. This then forces the right rear down (compared to the left rear). The result is a dynamic loading of the right rear, tending to cancel the tendency of the driveshaft torque to unload it. It is necessary, of course, to have adjustable coilovers when taking advantage of this trick, as the lower rate spring will require more compression to support the same load. Note that this is NOT the same as a preload. The load is applied dynamically, not statically.
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