IC length has nothing to do with it. IC position (height) has nothing to do with it. But, when you divide the IC height by the IC length, then divide the result by the ratio of CG height to wheelbase, and, finally, multiply by 100, you have the percent antisquat.ccrp wrote:...what IC length and position might give the most front rise?
In other words, it doesn't make any difference whether the IC is 50 inches out and 10 inches up or whether it's 50 miles out and 10 miles up, the effect will be the same.
This is because the resultant force acting on a freely pivotable link must have a line of action which passes through the pivot points. When viewed from the side, the rear axle assembly can be considered as one big link, having pivot points at the rear tire patch and the instant center. The resultant of the dynamic forces carried through the suspension links must then act on a line which passes through the rear tire patch and the instant center. (There are also vertical forces being carried through the springs and shocks, but these can be considered independent of the forces carried through the links. And, these spring and shock forces go to zero at 100% antisquat, anyway.)
An infinite number of lines...each representing one of an infinite number of values of percent antisquat...pass through the rear tire patch. So, if you want 100% antisquat, it's only necessary that the IC be positioned anywhere along that 100% antisquat line. The exact position is totally unimportant.
An extreme example is when the upper and lower links are perfectly parallel. Since parallel lines meet at infinity, it would only be necessary that the links be parallel to the line representing the desired value of percent antisquat. The IC would then be an infinite distance forward and an infinite distance up, but the result would be exactly the same as if the IC were only 50 inches forward.
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