BioMax's 4-link Article

A longer upper bar would (assuming the i.c. is set up properly) make the pinion point up towards the ends of it's geometric limits. And the i.c. would start to move behind the vehicle under bump (the wheel moving closer to the frame) instead of just getting closer to the rearend. A system where the upper bar is shorter will do the opposite. The i.c. will move behind the rear end under droop (when the axle moves away from the frame.) and the pinion will point down at the end of the travel.

When addressing the i.c. with a carrier bearing... That is my favorite! I have actually had a driveshaft made with a 6" long front section just so that I could install a telescoping rear section and move my carrier bearing where I needed it so that I could involve the driveshaft into my i.c. With 24" of wheel travel the amount of driveshaft "plunge" was only 3/4" of an inch. On an off-road truck, that is important in order to keep the driveline from destroying itself. You would address it just like the diagram above (on pootytang's post) the driveshaft would replace the tierod.

max your the man. i just stayed up all night reading all 7 pages.

hey max, im haveing problems with an ex-cab s-10 i bagged for my girl, its a trianglulated superlift four link from suicide, i set the topand bottom bars level at ride height. the top bars are an inch longer than the bottom. the problem is that the trianglulation is not aggresive enough and getting side to side movement. whats is the best way to set this up from start? how do you figure i.c. with this setup( has carrier berring)? how can you figure this with out pyhsically stretching a string to the front of the truck? fixing to do another one and want it to be right, for safety sake, plus i dont like haveing to redo poo.

how do you figure ic on a 4 link setup where there are two toward the front and the triangulated bars to the rear? Are you even able to.

Originally posted by kannedintegra



how do you figure ic on a 4 link setup where there are two toward the front and the triangulated bars to the rear? Are you even able to.

I'm afraid that is a whole lot like asking how to find the ic of an improperly set-up suspension. It can be found, but has little to no bearing on what you are doing. A 2-forward 2-reverse 4-link will never work for anything other than holding the truck off of the ground, reguardless where the ic is.

Hey Max. Is there any particular way to set up the triangulated top bars to maximise articulation for a bag over bottom bar set up??

I'm not exactly sure what you are asking.

If the upper bars are at least at 30

Thanks Max for that information pretty much what i was looking for.

hey max, with respect to instant center, what height should it be set at?   IE; if the lower bars are parrallell to the ground and the top arms are angled down the IC will be roughly the height of the lower bars, is this correct??

thats a good question...I have been figuring mine up near the headlights, with my lower bars facing slightly up at ride height.