True FRONT four link on an XJ?

[Incredible Hulk]

I just found this on the nagca forum. Sorry if it is a repost. This guy plated part of hte unibody frame, and then tied long arm mounts into those. But did it so taht it was a true four link! Here is a pic:

And another:

Just thought you guys might like to see that! It looks as though clearance would be an issue with the floorboards under full compression.
I am planning on doing something VERY similar to the plate and mounting to the unibody for my long arms mounts as well, without the four link part of it. Just wanted to see what yall thought of this.
Hope all is well.
josh

 

[Beezil]

there's really nothing to that, nothing more than a long version of the oem set-up, still using the tracbar

very easy to do, that could be built in a weekend without even trying hard.

looks like the lower links hang pretty far down, especially on the the axle end.

 

[Incredible Hulk]

Beez, alright here is my new idea:
Angle plate the insde and bottom frame rail from about 6in in front of the crossmember back past the crossmember about a foot. Leave the crossmember as it is, and then tie the mounts into the plate, whether by welding them on or bolting them through sleeved holes. I am leaning towards welding them though. Then, run some gussets back along that plate from the back of hte mount to help take the shock back further and spread the load. I am still planning on going inboard and up about level with the stock crossmember. So now the mounts are completely separate from teh crossmember but still spread out the shock back from one single point, and I think if we did it right they would be plenty beefy. I was kicking around possibly connecting the two mounts together in the middle somehow for strength as well- would that help?
What do you think of taht idea? Advantages/ disadvantages?

 

[Incredible Hulk]

Wow did I just hijack my own thread? Can I do that?

 

[Beezil]

I think what would help you is to plot the design that's in your head in a side-view to scale, snap a picture and post for discussion sake.

the design in the pictures you posted, succeeded in keeping all four links, plus the tracbar, at the SERIOUS expense of loss of ground clearance.

(ary, if you are reading this......something we need to talk about)

it doesn't look like theres much vertical seperation between the upper and lower links at the frame end. I don't know what the fabber's goals were, but it makes me wonder why he just didn't go with a simple radius arm design, and have a single pair of arms he could have tucked up more. because if you would intend to tuck yours up more than this guy, you run out of room for link seperation really quick, and more importantly, the way to FAB a bracket to attatch a link to. The unibody is a bitch in this regard.

 

[Bender]

I don't completely understand the dynamics of an IC and how it effects the vehicles handling but it would seem having both the upper and lower arm mounting so close to eachother would net virtually the same driving characteristics as a simple radius arm setup. Perhaps the only gain is from a safety standpoint with the four seperate mounts. From the pics of people rigs that seem to work fairly well if that setup in the pic above were done with radius arms attached to the inner UCA mounts while cutting off the current LCA mounts would he not get pretty much the same driving characteristics with less loss of ground clearance?

For a little education.....what effect on braking, accelerating etc would having the two arms mounted close together in comparison to a radius arm attached to the upper/inner mount?

 

[Incredible Hulk]

I think what would help you is to plot the design that's in your head in a side-view to scale, snap a picture and post for discussion sake.

the design in the pictures you posted, succeeded in keeping all four links, plus the tracbar, at the SERIOUS expense of loss of ground clearance.

(ary, if you are reading this......something we need to talk about)

it doesn't look like theres much vertical seperation between the upper and lower links at the frame end. I don't know what the fabber's goals were, but it makes me wonder why he just didn't go with a simple radius arm design, and have a single pair of arms he could have tucked up more. because if you would intend to tuck yours up more than this guy, you run out of room for link seperation really quick, and more importantly, the way to FAB a bracket to attatch a link to. The unibody is a bitch in this regard.

I agree with you on this one, I will try and mock something up and snap a pic.....
I am NOT planning on running two arms. I am still planning on running just a normal RE style long arm with an upper attached to each long arm, not trying to reinvent that part. SO, I am just planning on fabbing that ONE bracket per side to mount the long arm in, which will be mounted to the frame plating. make more sense now?

 

[MrShoeBoy]

it doesn't look like theres much vertical seperation between the upper and lower links at the frame end. I don't know what the fabber's goals were, but it makes me wonder why he just didn't go with a simple radius arm design, and have a single pair of arms he could have tucked up more. because if you would intend to tuck yours up more than this guy, you run out of room for link seperation really quick, and more importantly, the way to FAB a bracket to attatch a link to. The unibody is a bitch in this regard.

What would be a good link seperation distance and then why is that a good distance? I guess that I dont understand link seperation, time to go back and reread the god of suspension threads.

AARON

 

[Beezil]

I am NOT planning on running two arms. I am still planning on running just a normal RE style long arm with an upper attached to each long arm,

right, this is esentially, a radius arm set-up.

TWO arms to locate the axle with a trackbar, and a pair of uppers to control axle rotation.

do some searchin on radius arm set-ups, plenty of good threads....

I have not seen the RE set-up....

post a pic?

 

[Incredible Hulk]

Yes, we are saying the same thing, just when I hear radius arm I think the ford version.
This is the "RE" version I was referring to.

 

[Beezil]

gotcha.

the above is a radius arm, each arm operates in an arc with a single radius

 

[Incredible Hulk]

gotcha.

the above is a radius arm, each arm operates in an arc with a single radius

Ahhhh, sank you Beezil-san

 

[vintagespeed]

If you want a hi-clearance & strong radius arm mount, do what I did for my upper control arm. (3link + TB here)

I made a triangulated mount within the frame rail on the passenger side. The mount sits on 11" of plate that is rossette welded to the inside of the frame and fully welded in various spots.

It's very strong & would work for a radius arm setup, would keep the mounts above the bottom of the frame, keep the x-member & etc.

I used 2.5" JJs on all links.

 

[JBrobeck]

Other than the caster traveling through a constant arc (increasing/decreasing through travel) what is the disadvantage of a radius design over a 4 link, considering both being long arm set ups? I could see very little to NO on road difference, but I have not wheeled enough with either set up to know the advantage. I do understand that without unpinning or removing one of the upper links on the trail, the links will fight each other due to the caster change through travel, but is there anything else I am missing?

 

[RCP Phx]

A stock arm setup at higher lifts(w/o drop brackets) goes thru way more caster change!

 

[Incredible Hulk]

If you want a hi-clearance & strong radius arm mount, do what I did for my upper control arm. (3link + TB here)

I made a triangulated mount within the frame rail on the passenger side. The mount sits on 11" of plate that is rossette welded to the inside of the frame and fully welded in various spots.

It's very strong & would work for a radius arm setup, would keep the mounts above the bottom of the frame, keep the x-member & etc.

I used 2.5" JJs on all links.

Since that sounds exactly like what I want to do, I would love to see some pics! Post em up! Yer web site aint workin.....