Just like everything else, there are compromises to be made. The 3 link or 4 link locates the axle and some other item (coil-overs or air bags ) provides the load carrying portion of the suspension, as opposed to the leaf springs which do both. To allow the left and right side to go up and down on their own, the bars have to twist so some compliance has to be put into the ends to allow the twist. Rubber does a nice job of this but rubber also allows more compression and allows the axle to wind up and hop. That's why Ford put the quad shocks on the 5.0 Mustang and their compromise didn't work real well. Urethane bushings stiffen this joint up a bunch but don't allow as much twist and take their toll on ride. Solid spherical joints allow all sorts of compliance but take their toll on ride. This situation is further exaggerated with a triangulated 4 link which has the upper and lower bars swinging through different arcs on different planes. This is the delema I am facing. However this setup does get rid of the panhard rod which is a necessity on a parallel 3 or 4 bar setup.

The one thing that the 3 or 4 link allows, is movement up or down of the attachment points if multiple mounting holes are used and hence, weight transfer characteristics can be dialed in for launching. Purple's setup is certainly taking advantage of this. As well, if adjusters are added to either top or bottom or both sets of bars, pinion angle can be relatively easily adjusted.

Sorry about the long-winded reply.

 

Ah man I thought this thread was about womans behinds. What a drag.