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Discussion Starter #1
I know this has been visited before but I can't seem to get a straight answer:

Is there a standard angle required to eliminate a trac bar?

I understand that the more angle the better b/c the angles are fighting each other at a greater degree. But, I also understand the longer the angle the less resistance put on the suspension.

It seems that any decent angle going to near the same point will fight each other to keep the rear tracking straight. I do understand the lowers need to angle out towards the tires, but can't figure out the uppers. (working on a 4-link)

Why do some guys have such short "triangles" and others use much longer? <IMG SRC="smilies/skull.gif" border="0">
 

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<IMG SRC="smilies/rolleyes.gif" border="0">

[ 09-06-2001: Message edited by: Qbert ]
 

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Discussion Starter #3
What happened to all of the "suspension Gods" out there? Someones got to have an answer. <IMG SRC="smilies/sleep.gif" border="0">
 

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Say what? <IMG SRC="smilies/rolleyes.gif" border="0">
 

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First, I have seen it done, but personally am dead against the redesign and removal of a front track bar for a vehicle that sees the street. The loads that are present during steering, IMHO, are too great to justify this. The rear is can be done if done correctly.

Now, to answer your question:
There is no magic, standard angle that can be applied to the control arms to remove the track bar. There are too many factors, some of them being:
- user/driver tolerance to loose suspension/handling, poor handling on the street
- use of joints, play in the joints (heim vs. poly vs. rubber vs. ...)
- compound angles, lengths of joints
- amount of suspension travel that you want

A properly designed suspension does not need to induce any "fighting" or loading between the links throughout the range of suspension travel that the suspension is designed for, regardless of the angles. Often, though, offroad high-travel suspensions have little of no consideration for on-street handling (and good or bad on-street handling just kinda happens).

I suggest picking up a good on suspension design, it'll answer some of your questions about link lengths and what-not.

--Rob

Originally posted by P&T jeeps:
<STRONG>I know this has been visited before but I can't seem to get a straight answer:

Is there a standard angle required to eliminate a trac bar?

I understand that the more angle the better b/c the angles are fighting each other at a greater degree. But, I also understand the longer the angle the less resistance put on the suspension.

It seems that any decent angle going to near the same point will fight each other to keep the rear tracking straight. I do understand the lowers need to angle out towards the tires, but can't figure out the uppers. (working on a 4-link)

Why do some guys have such short "triangles" and others use much longer? <IMG SRC="smilies/skull.gif" border="0"></STRONG>
 

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Discussion Starter #6
to be more specific:

I am talking rear suspension only and plan on using full bushings on tera style arms...
 

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If its gonna see any street driving...DON'T remove it..
off road do what you want!!
If your gonna remove it and drive on the street let me know where you live and I'll stay away when your out there!!!
 

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Discussion Starter #8
Sorry, I just don't buy that. There has to be some geomtery to make it streetable. If guys are doing it in trucks that go a hundred mph something has to make it track straight! <IMG SRC="smilies/skull.gif" border="0">
 

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I run SOA w/37" boggers and when I hit 100mph...let me tell you,its not something you want to do daily!!! I could run 80-90mph and feel very comfy, but I got leafs not coils. Without a track bar your gonna have lateral movement unless everything is mounted solid!! And thats not good for flexin! With 8"+ I would def run track bar front and rear....I assume (hate that word) you run a Skyjacker system?? If so give Ken in tech dept a call and see what he says.
 

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Discussion Starter #10
No Skyjacker, no thanks... I prefer combining different componets one at a time. I've got a conglomeration of stuff under there. I've got a custom rear susp. but its time to redo it. Don't have that damn ME degree.

I know it can be done. There might be some lateral movement but not much if you use standard bushings, kick the lowers towards the tires, and the uppers to the diff.

I just want to know how important the actual measurment of degrees on the uppers are...
 

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Discussion Starter #11
Does anybody know if CJLagos uses a rear track bar? I don't think he does.
 

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I have Currie's triangulated rear on my TJ. I love it. They use bushings at the frame end and Jonny Joints at the axle side. Why are you saying the lowers need to be pointed to the tires? Mine aren't. I think the bushings at the frame for the uppers are wearing a little because I do notice a LITTLE lateral movement. But it is totally safe. If it is even there. Really it's a Jeep I don't think I would ever want to go much faster than 80 But i'll bet it would be stable at that.
 

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Originally posted by P&T jeeps:
<STRONG>Sorry, I just don't buy that. There has to be some geomtery to make it streetable. If guys are doing it in trucks that go a hundred mph something has to make it track straight! <IMG SRC="smilies/skull.gif" border="0"></STRONG>
If you can design it so track bars are not needed on a TJ's quadra-coil suspension with front and rear solid axles, Jeep will be on your doorstep in the morning with a big-money job offer. You may see trucks without trackbars going 100 mph but they're not running a quadra-coil suspension with solid axles either. Those guys are either running IRS or solid axles in the rear with leaf springs and IFS in the front. Not even close to a TJ's suspension design that requires track bars to keep the axle centered and provide the proper alignment required for good steering.
 

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Discussion Starter #14
Thanks TJpwr, finally someone seeing where I'm going w/ this. And, I have no desire to go 100mph, I was just making a point.

Jerry, I'm not trying to make a production vehicle here. I know there will be some adverse handeling characteristics and am ready to deal w/ them. I am just trying to minimize them, I know this can be done!

The truck that I refrence do run solid axle rears w/ coil suspension; coil-over b/c of speed, dampening, and travel requirements; but never the less coil. I have no concern for the front right now, so if it is tracking straight then all I need to do is get the back to do the same, with NO track bar.

<IMG SRC="smilies/skull.gif" border="0">
 

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P&T - I don't have an answer for you as I'm working out how to do it on mine still. You'll have better luck searching and posting the Gen 4x4 board on this one.

I gotta ask though.... Did anyone really read the question? Or did they just spout off the first objection that came into their heads? <IMG SRC="smilies/rolleyes.gif" border="0">

Paul
 

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Originally posted by nasvik:
<STRONG>P&T - I don't have an answer for you as I'm working out how to do it on mine still. You'll have better luck searching and posting the Gen 4x4 board on this one.

I gotta ask though.... Did anyone really read the question? Or did they just spout off the first objection that came into their heads? <IMG SRC="smilies/rolleyes.gif" border="0">

Paul</STRONG>
yeap, spouting id have to say... <IMG SRC="smilies/rolleyes.gif" border="0">

i believe once you get the correct angle of the uppers it WILL work, i too have been givin this some thought... it almost easy to visualize as to why it would work... in fact i think if done correct will keep it there just as good, but it will not have the binding characteristics of the typical 4 link tj set up... imho thats a good thing
 

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Discussion Starter #18
Thats exactly what I'm thinking... Logic tells me that any decent amount of angle will hold it well, especially if the lowers are angled out a bit too.

I think I'm gonna go w/ the lowers and uppers almost the same length. Both of them mounting at almost the same place on the frame, but about 7" difference on height b/c that is the difference of the two mounting locations on the axle. Gonna try to keep them parallel so they move symmetrically to keep the pinion at the same angle.

Best I can come up with...
 

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I hate to say it but I believe both the Liberty and WJ have triangulated rear susp. w/o the trac bar. Or is it they use a 3 link... Hmm.. it's one of the two but I do believe the trac bar has been eliminated.

TmbrRtlr
 

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I too am redoing my suspention. I,m adding D44,s to my 97 TJ. I am toying with the idea of doing a 3 link. What do you think of a wishbone upper on a 3 link. I think a wishbone will allow me to do away with the rear trac bar ? I,m gonna do alot more research before I jump into this one ! <IMG SRC="smilies/biggrin.gif" border="0">

<IMG SRC="smilies/jeep2.gif" border="0"> __(OIIIIIO)__ rOkOn
 
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