General triangulated 4 link numbers

Is there any general rules to follow with 4 links, I have read another place that the uppers should be atleast 70% the length of the lowers, and around 40* angles on the uppers, things like that.

What about the bar ends? Best to have parallel with the rear, or perpinduclar to the bar? Does that make sense as a question?

i've done 30" lowers and 33" uppers on the last 2 setups i've done.. both mounted to the same crossmember (not at different lengths from the rear end.. but at the same) and no pinion change throughout the whole range on either setup.

In most cases, the upper bars should be equal to or shorter than the lower bars, but there are a few cases where a longer upper would net the results that you are looking for...But that's not that often. There is no set number for upper to lower ratios, so usually what determines the lengths is your confines. If you can only fit a 12" upper bar, a 36" long lower isn't going to be necessary. In the all to common case where you are limited to a short upper you can run the lower bar as long a twice as long as the lower, but you would need to spend the extra time calculating out the pinion angle. On most minis, the confines are not very restricted so nearly equal lenth bars is easy and preferred (by me.) Keep in mind though that the effective length of a bar is calculated by the front to rear length not the actual length of the bar. For example on a triangulated system, the triangulated bars would be longer because they are angled. Make sence?

As for how to orient the bushings, that is completely preference. I prefer them to be parallel to the rearend instead of perpendicular to the bar. At some point the bushings that are in line with the bar will bind so that would need to be taken into consideration.

thats sorta what i thought, with the bushings. parallel with the bushings (at some point) would bind after the perpindicular to the bars.

as for effective length, i didn't know that, so that's new to me.

so if you have your uppers and lowers mounted at the same points, just higher/lower than each other, your uppers will be a tad longer, yet act as the same length....

...sorry, I almost forgot...

The ideal amount of triangulation is 45deg, so that the triangulated bars are actually 90deg from each other. Anything less than that starts becoming less effective. Not every vehicle has room for that so the acceptable amount of triangulation depends on how compliant the bushings are and how rigid the mounts are. But in every case, run as much triangulation as possible.

Max as far as your last post goes concerning triangulation and the bushings go, would it be better to run heim joints so that would elimate the flex of say a poly bushing if you couldn't get 90 degrees of triangulation?

Posted by Max:
At some point the bushings that are in line with the bar will bind so that would need to be taken into consideration.

You could also eliminate this, to a point, with heim joints as well right?

72bumpside- yeah, assuming that your uppers bars are triangulated.

Chris- Heims are great, they are just expensive and are also rough riding. They aren't too bad, but you can tell a difference and on a daily driver they are probably not desireable. Like I said, I run the bushings so that they are parallel to the rearend and that seems to work really well.

I guess that I never noticed a difference because I have always run heims so I don't have anything to compare ride quality.

Don't get me wrong, I would prefer heims over anything, they're just not as "user friendly" as a compliant bushing. Ferrari built a car that was all heims and it got a lot of complains about how harsh it felt. There is a reason that manufacturers don't run them, besides cost.

Understandable, I have read in some books that it can be harsh but you can eliminate play and keep tolerances tighter. I guess you could compare it to solid mounting a motor in the chassis.