Ok after some further investigation on my truck getting ready to race again I found that I have started to bend the axle housing (I also bent my upper coilover crossmember) so I got to thinking that since I am going to have to replace the axle housing anyway, and I figure the bent axle is from the coilovers bieng mounted inside the frame rail I would remount them outside the frame, and switch to the triangulated 4 link setup.
So first I need to design it before I get crazy on doing that and thats what I want help with, I know the basics of coarse but one how to determine upper bar length to keep from binding (I assume based on lower bar length) 2 how solid side to side is this setup, would I be advised to go ahead with leaving my panhard bar in place? 3 how heavy steel do I need to worry about getting IE is 1" .140 wall DOM strong enough or do I need bigger (figure on using 3/4" rod ends)
I have looked at skipped links setup and don't know that I will get that fancy on the bracing for the housing but then again who knows. So give me some ideas guys, I know this is the smartest bunch around.

 

If you have microsoft excel, or access to it sown load & try this out,

http://www.pirate4x4.com/forum/showt...ink+calculator

The link above will take you to the thread on pirate, there you can find the calculator.

You will be able to take measurements from you truck & base a link design, then alter it to work the way you want, all the while keeping it within the limits of the truck.

With a trangulated 4-link, you will not be able to use your pan hard bar, if used it WILL, cause binding,

As for side to side stability, the greater the angle between the upper bars (with in reason) the more stabe it will be, according to all the info I have read, My uppers are a bit shy of what is recomended, With that said I have no issues of latteral stability,

If I were building your set up, I would use 1.5" .120 wall, H.E.R.W. tubing, & 3/4 rod ends, proper fabbing & welding & you should have no issues there,

Now what to watch for with the triangulated 4-link, Rear steer, this can be changed & tuned, just keep an eye on this when designing, the link calculator will show you what % roll over steer your set up has,
The reason you need to watch this is, when one rear tire or the other is lifted up, ( one rear tire is in a hole or the engine is twisting the truck up) it will try to drive the truck in one direction or another, Belive me, this can be very UNhandy,

I'll see if I can find more info on off road style 4-linking for you to check out,
I have but loads I've collected, but it's all in paper form.

 

no input, just wanna follow, sounds like it's getting better and better

 

Me too. Post lots of pics It would seem to me that if it is designed properly, you wouldn't need the track bar. I don't think monster trucks use them.

 

I replied to this thread at around 3:00 this after noon & it still has not put the post up,


If the info I posted is not here by tomarrow after noon I'll post it again.

 

I think thats a real smart move Rob. I wish I had first hand experience to share with you, so the following is only from second hand experience and observation. You should have no worries with side to side slop. They can feel a bit "odd" on the road but for your uses I doubt you'll even notice. As far as the sizes your tossing around, I really think that 1" .140 wall DOM with 3/4 heims is on the light side. Now, granted, I tend to over-engineer, and you DO have a relatively light rig; but with your level of horsepower, airtime prone tendencies, and your typical mudrag whoops......well, I think its best to go with heavier links/heims. On the plus side you won't be coming down on rocks which is usually one of the biggest link eaters, so you don't have to go super stout like .250 wall. I wouldn't skimp on the heims either. I really like Evolutions heims, plus they are rebuildable. Just my two cents, we'll see what the other folks have to say.

 

You do know your the one person I was hoping would chime in here (no offense to anyone else but his is the baddest truck on FTE IMHO) I look forward to what you have to say about this, and probably will have plenty of questions as I go along for you.

 

Well I can't believe that the first post I put up did not show up here, I had linked to the 4-link calculator thread, maybe that kicked it out,

Any way, for what you are doing I would use 1.5" .120 wall, H.E.R.W. tubing, or D.O.M. if you want,
A good quality 3/4 hiem should hold just fine, I am running the $30.00 jobbies on my truck with no issues so far, A good piece of mind would be to run the evo joints like Pro suggested, they make them in several sizes now & there 3/4 joint is much stouter than the ones I am runing,

Latteral stability is not a problem with a properly set up triangulated 4-link, the thing you have to watch for is the % of rear steer, which can be changed while building & tuned when complete, rear steer becomes more of an issue in articulation, so if your not droping a rear tire in a big hole you probably will not have a problem, The issue I have with it is my engine twists the truck so hard it will actually rear steer like it is articulated, this in turn drives the truck to the left, Like I said this can be tuned to a point, & I plan on working on this (just been busy trying to get a tranny to work)

I'll find the link to the 4-link calculator & post it up, if it does not let me I'll email it to you,
You can mess with the calculator & try different ideas to see how differently the truck is suppose to react,

If you have any particular questions Just shoot, I'll do what I can to help,

 

Crap, it just booted the last post with the link to the 4-link calculator,

I'll just emai it to you,

 

I got the emial, and I see why it booted it off. Thanks, I will play with it and ask if I have questions.

 

This statement in conjunction with your horsepower and pretty sheet metal gives me major butt pucker. I've seen pictures posted of those heims completely torn out (end split right open) and I really have a feeling that on your truck or Rob's truck it would only be a matter of time. That's cool that Evo is doing smaller heims now. Do you know what the cost is?

The flatter your links are (as in near parallel to the frame) the less rear steer you'll experience. This is part of the reason most pro MT's use low mounting points for the links. It will cost you some ground clearance but that shouldn't be an issue with mud drags anyway or if it is you need bigger tires. My only other helpful tip I've pulled from MT's is try and make your upper and lower links the same length if at all possible. This will keep your pinion angled properly throughout the entire cycle of the suspension and will also help keep the rear steer to a minimum.

Btw, if you linked the calculator from Pirate it won't post. All Pirate links have been . . . uh . . . pirated by FTE.

 

I learn somthing new everyday.

About the 3/4" joints the Evo joints are $70.00 a pop.

I do check my joints reagularly, I believe there will be some warning, (streaching of the eye, & getting loose) before tearing the end out.

I am also aware that there could be NO warning, but feel that chance is slim.

I will agree that the $30.00 joint is inadiquate in a lot of situations, but I have run them in two seprate rigs, both relatively heavy & respectable horse power levels & niether had issues, I would not suggest just anyone run them, but I have a feeling that Rob is up to par with preventative maintenance, & could get several years of service from the $30.00 joints. especially in his application,


Ivan has brought up a good point in the fact that the cheaper 3/4" joints are NOT the way to go in rougher applications, so the guys reading this thread for ideas on there rock crawlers, & huge mud bogging tractor pulling rigs, keep in mind I'm suggesting components for a light wieght smaller tired rig with a lot of power, just not a lot resisting it,

My reasoning for running the 3/4 joints is,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Curiosity,

 

Thats a point worth stressing, both of our rigs may be running lots of HP, but both are A. lighter than the typical offroad rig, and B we don't go trail running with them, there is a huge difference in what you can do and get away with in a mud drag or even bogging truck than what the typical offroad use truck does. Basically skipped's truck and mine are more akin to a prostock drag car then to something like Ivans, or Pro's trucks.
So basically this falls under "Don't try this at home"

 

Hey look my origonal post from yesterday finally dicided to show up. now it looks like I can't even remember what I already posted from day to day,

 

After some thought, I agree with Ivan that flat link bars will help with the rear steer issue, but I think it will put your anti squat in a less desirable range, when you play with the link calculator you'll see what I mean,

Any way, just thought I'd throw that out there,
If I do not get back to a computer later today it wll be sunday night before I get back to this thread, I'll be bogging in Reno tomarrow night.

While your researching here's another good read, if you havn't already read it,


http://www.4wheeloffroad.com/techarticles/suspension/131_0307_four_link_suspension_part_2/index.html