long travel rear: 4 link with panhard bar vs wj style 3 link?

[yotatake2]

Hey guys, so I'm planning on making my truck long travel in the future and for the front I'm probably going to go with the total chaos LT kit. But for the back, I'm planning on something more home brewed. My concern is the panhard bar. Under stock travel numbers, the parnhard bar probably does just fine, but anything past that and I'm worried that the axle will swing out to the side too much just due to the geometry of the bar and throw off the balance of the truck. My proposed solution to this is replacing the upper control arms with a triangular control arm like the one in wj jeeps. For those not familiar with this design, it's basically a triangle that attaches to the frame at two points and the top center of the axle at the third point. But unlike the wj arm, mine would use rod ends for more articulation. I looked under the truck and it seems like if I cut the exhaust before the axle (right after the muffler) I should have plenty of room to fit a triangular linkage.
Thoughts?

P.S. I understand that this option would require that I make new mounting points on the axle and frame. I am planning on running a tundra rear axle to match the width of the front and more easily fit shock hoops on the side of the frame in the fender without hitting the wheels. Plus a stronger axle won't hurt.

 

[UnderFire]

The only true long travel rear set-ups I've seen are on leafs in the rear, but I've seen very few, If I ever ending up going long travel like i want to, I plan to use leaves and a cantilever shock set-up, or possibly outboarding the shocks to the inside of the wheel wells like you mentioned.

 

[yotatake2]

The only true long travel rear set-ups I've seen are on leafs in the rear, but I've seen very few, If I ever ending up going long travel like i want to, I plan to use leaves and a cantilever shock set-up, or possibly outboarding the shocks to the inside of the wheel wells like you mentioned.

Just out of curiosity, what would be the advantages of leaf springs over a linked setup with coils? Cuz I have considered them. Is it mainly simplicity?

 

[Asaspades93]

[MENTION=92884]snivilous[/MENTION]

 

[UnderFire]

Just out of curiosity, what would be the advantages of leaf springs over a linked setup with coils? Cuz I have considered them. Is it mainly simplicity?

Yes, mainly simplicity and cost, a properly set-up linked rear will outperform leafs, but is not easy to achieve, especially with the added constraints of an SUV.

 

[IBallEngineer]

I think both designs would work, I like the idea of the center link, but the panhard rod will actually give you more flex. Sounds like you want more of a high speed set up anyway so that could be better. How long will your lower arms be? Most of the JK long travel setups retain the panhard rod and do just fine. I haven't been on Pirate 4x4 for a while, but they have some really cool calculators for this sort of thing. Of course it's jeep centric, but the geometry works anywhere.

 

[Andy in Pa]

A triangulated upper is the way to go for flex, the stock WJ setup is still a bit restrictive. The aftermarket replaces the TRE type setup with a johnny joint or heim. Do your research though if you plan to drive it on-road. This type of setup has a tendency to feel very loose at speed. Many run a Currie Anti-rock sway bar with this setup to gain some flex control back.

 

[yotatake2]

A triangulated upper is the way to go for flex, the stock WJ setup is still a bit restrictive. The aftermarket replaces the TRE type setup with a johnny joint or heim. Do your research though if you plan to drive it on-road. This type of setup has a tendency to feel very loose at speed. Many run a Currie Anti-rock sway bar with this setup to gain some flex control back.

I have also heard of that looser feeling on road with this setup. Either way, I plan to get stiffer sway bars front and back since long travel basically increases the moment arm acting on the sway bar.

 

[yotatake2]

Yes, mainly simplicity and cost, a properly set-up linked rear will outperform leafs, but is not easy to achieve, especially with the added constraints of an SUV.

I'm actually planning on doing the same V8 swap that singtoe did a while back so I would be installing/fabbing all the long travel components while the body is off the frame so it should be alot easier to work with.

 

[absalom]

There was that guy who built a cantilevered 2nd gen ... thing was amazing. He had a full IR setup for hunting rodents at speed during the night.

 

[snivilous]

Within the next few weeks I'm gonna begin designing my LT rear. After a lot of research and thinking I'm currently settled on doing an "inverted" triangulated 4-link and cantilever. So the uppers will run straight and then the lowers will be mounted as close to the diff as possible (not under it so I don't lose clearance) and then angled out. This will be because the gas tank and muffler are in the way of having the uppers triangulated. You could then run shocks up to a cage inside of the truck (easiest method) or run them outside of the frame etc, but I think a cantilever wouldn't be too bad and have the shocks/coilovers where the spare tire is (can't fit a spare anyways). Because of the high travel numbers anything besides a coilover would get hairy with the length of spring needed.

Some guys on dezert rangers told me just running some good shocks outside the frame would work surprisingly well. I don't really care for that approach since my front suspension is kick ass and I want the rear to be super cool too as well as pull more travel than my front will (so I want 18" or more rear travel ideally); not to mention the rear has always been the limiting setup for me, so I'm gonna go to town on it and hopefully never look at it again.

[MENTION=75445]4Running Daily[/MENTION] WAS :boxing: going to go LT and he was going to do a triangulated rear with shocks into the body, or was playing with that idea. [MENTION=84548]NoHair[/MENTION] is the guy with the 2nd gen who did the cantilevered rear, though as I recall he has leafs.

EDIT: Oh and then I might run an anti-rock bar, but I would rather integrate an unlockable sway bar into the cantilever if feasible. Really want a sway bar since people have recommended it and I'm gonna probably be running 100-200lb/in spring rates on all corners so it'll body roll like a SOB.

 

[4Running Daily]

Within the next few weeks I'm gonna begin designing my LT rear. After a lot of research and thinking I'm currently settled on doing an "inverted" triangulated 4-link and cantilever. So the uppers will run straight and then the lowers will be mounted as close to the diff as possible (not under it so I don't lose clearance) and then angled out. This will be because the gas tank and muffler are in the way of having the uppers triangulated. You could then run shocks up to a cage inside of the truck (easiest method) or run them outside of the frame etc, but I think a cantilever wouldn't be too bad and have the shocks/coilovers where the spare tire is (can't fit a spare anyways). Because of the high travel numbers anything besides a coilover would get hairy with the length of spring needed.

Some guys on dezert rangers told me just running some good shocks outside the frame would work surprisingly well. I don't really care for that approach since my front suspension is kick ass and I want the rear to be super cool too as well as pull more travel than my front will (so I want 18" or more rear travel ideally); not to mention the rear has always been the limiting setup for me, so I'm gonna go to town on it and hopefully never look at it again.

[MENTION=75445]4Running Daily[/MENTION] WAS :boxing: going to go LT and he was going to do a triangulated rear with shocks into the body, or was playing with that idea. [MENTION=84548]NoHair[/MENTION] is the guy with the 2nd gen who did the cantilevered rear, though as I recall he has leafs.

Still planning on it

But I have tons and tons of information on linking the rear. I'll post it up when I get time this weekend.

 

[yotatake2]

So I've done a little more research and now I've just come up with more options lol.
Here's what I have so far:

Geometry options:
triangulated 4 link
inverted triangulated 4 link
WJ style 3 link

Shock/coil options:
cantilevered shocks w/ coils in stock locations
cantilevered coilovers
side shock hoops w/ coils in stock locations
side coilover hoops

I really like the idea of the coilover hoops on the sides but i don't know if I'll be able to fit a coilover capable of going through 18 inches of travel in the fender well, especially since it would be a 1:1 motion ratio. I don't think I'll have an issue with fender to wheel space because that should be well over 6 or 7 inches with the tundra axles. With that said, i'm wondering what is the max travel I can get out of a non-cantilevered, 1:1 setup. And I really don't want to cut into the cab since I still want to be able to camp in it.

 

[ARC]

I have very limited knowledge on this sort of thing... but always thought a 1st gen Tundra axle with a triangulated 4 link would be the way to go. Never seen it done and I am sure there are a million complications I am not thinking of...

I say all that basically to subscribe and live vicariously through you brave souls that figure this stuff out.

opcorn:

 

[JamesDean91]

I was looking at something like this

 

[JamesDean91]

This also figure instead of the bar just brace it in the wheel wells and cap over the towers.

 

[4Running Daily]

This also figure instead of the bar just brace it in the wheel wells and cap over the towers.

Any more pics of this setup?

 

[yotatake2]

I was looking at something like this

are you referring to the mounting method or the air shock? I didn't think of that. Any thoughts on air shocks in the rear? they would be a bit more compact than coilovers. but I'm guessing they're pretty pricey?

 

[JamesDean91]

Any more pics of this setup?

Not from the side. Wish I did lol.

 

[JamesDean91]

are you referring to the mounting method or the air shock? I didn't think of that. Any thoughts on air shocks in the rear? they would be a bit more compact than coilovers. but I'm guessing they're pretty pricey?

Both. It's what I planned on running on my runner, ori struts and french shock towers. I have the clearance if I measured right to do it now with my stock rear axle 1.25 wheel spacers and stock offset wheels.