Optimal Tri-4 link converging angle?

Greetings,
I was wondering if there was a prefered (or minimum) angle of triangulation in plan veiw for the lateral constraint bars in  a tri-4 link or satchel link design? I am curious because of :
... #1: any increased potential for bind during travel.
... #2: the forward forces put on an angled bar (especially the lowers in a satchell link setup)
.... #3: does a sharper angle influence how well the axle stays centered.... in other words is a 20 degree angle(where the 2 links converge at a 40 deg angle), less effective than a 45 deg angle (where the two bars converge at 90 deg).
.... #4: having the roll center (where the links converge) under the cab area about 12" from the ground. Is this an issue for handling performance in a  "nose heavy" mini?
 
I'm in the final stages of design a Satchell link with 30" long lower bars, mounted on the ends of the axle and triangulating in at about 20 degrees in PLAN view. (the forward mount of the lower bars would be around 10" from inside the frame rails.)
It will be a performance designed, coil-over rear suspenson for a 91 S10, V8, 5-spd. Bars are 1.5"x.25" DOM tubing w/ one Johnny Joint/Delrin on 1 end of each bar.
 
I hope this question makes sense?

The strongest angle were the two bars converge would be a 90 degree angle, 45 degrees at the wide end. I'm sure 40 degrees or even 35 would be fine. If you keep the bushings parallel to each other you won't have any problems with binding. As far as preformance goes it will depend on exactly what you are looking for, cornering, drag racing, etc.

If you build the lower bars out of the correct material for your application you shouldn't have flex issues. They will flex to some extent during hard acceleration, but a straight bar will too. You just need to be more cautious of it in a Satchell link, because the angle of the bars makes them more susceptible to flex.

For my application, I am curious to see how my spherical bushings w/ DELRIN hold up. This will be my first experience w/ Delrin. Has anyone used this for their daily drivers? How is it holding up? Would like to hear user's opinions.    I'm only running about a 350 hp/300 tq motor. I think I'll be okay w/ the 30" long 1/4" x 1.5" DOM tubing....should be overkill! We'll see, I guess. Thanks guys!

Ya you will be fine. That's thicker than I would run in that application.   I haven't used Delrin as a link mount on anything so far, so I can't tell you much about it. I've used it as a pivot for other things, and to attach transmission cross members to frames, but that's about all. I don't think it wears very quickly at all.

If you are that concerned with flexing I would look at running Heim joints instead.  1.5"x.250" is overkill for that, you could easily run 1"x.250" without problem.  I have been using it forever because all you need to do is chase the hole with a tap drill and 3/4x16 tap.  I have been running 1" hex aluminum bars on my truck for around 8 years without any problems with app. the same horse/torque you are.

Edited: 2/23/2009 11:08:48 PM by TwistedMinis

He said he is running a spherical bearing. That is either a rod end (Heim is a brand) or a uniball.  I did a satchell link with 1" .188 wall DOM. I am pretty sure they don't make 1" .250 wall tube. I want to run a satchell link on my new project, and I planned on using 1.5" .120 wall. The plan is for more power than you are thinking about.

Yeah, I'm using Johnny Joints... aka uniballs, super-pivots & a coupla others I can't remember. If I no likey, I will ditch them for some 3-piece Teflon Heim Style Ends. I figured they'd be worth the try. I'm probably making mountains outta mole hills w/ the lower bar flex issue, but the compound angles on the lowers had me a little psyched. Yep....overkill for me sounds about right. I wish I knew of more Satchells to take examples of (so I can learn from other people's mistakes).... I still don't understand why it isn't a more widely used 4 bar application?

I get 1"x.250" DOM all day long around here.

what's a satchell link?