URF 3 link questions

[Matt S.]

Ok Jes, Crash, and Jeff. Tell me. Do you think you could fit YOUR 3link long arms under a STOCK coiled cherokee?

I ask in the open because I am sure we will talk about this 3link and can use this for search!

 

[CRASH]

Stock height?

 

[Jeff 98XJ WI]

I don't even have my upper link on and I would say NO. I think I need to add quite a bit of bump stop to the front end (compared to stock) because the upper link will hit things if the front compresses too much. I'm ok with that though, because I needed to add bump stop to keep the 35's out of the fenders anyways. If you want as much compression as you can get (no added bump stop), then I don't think there would be room for the upper link in my AW4 equipped rig. Who knows, if you ran an upper link with a bend or two, perhaps one could make it fit? Jeff

 

[Matt S.]

Stock height?

Basically. I have really been turning the wheels very seriously on the suspension and axles. I ask because even with the cons of portals, its a viable option. I was thinking that I can run nearly a stock hieght suspension and still obtain 14+ inches of travel.

I REALLY like the way the URF 3link works, and would be worth semi-copying.

What say you?

 

[CRASH]

It's very tight. I think with the extra torque induced by the portals, the uper arm would have to be stout. As least as stout as Jes' and mine. 1.75" x .120. That's a big upper to try and fit into the narrow space between the bellhousing and tunnel. Now, with a little tunnel massaging, and maybe a very stout smaller diameter upper (1.25" x .375?) it could work.

I love the idea of portals. How about oil pan issues?

CRASH

Basically. I have really been turning the wheels very seriously on the suspension and axles. I ask because even with the cons of portals, its a viable option. I was thinking that I can run nearly a stock hieght suspension and still obtain 14+ inches of travel.

I REALLY like the way the URF 3link works, and would be worth semi-copying.

What say you?

 

[David Taylor]

I love the idea of portals. How about oil pan issues?

CRASH

Is up travel over rated for a crawler ? What about limit the up travel in the middle of the axle ? But still have travel at the wheels.

 

[Roll-over]

It shouldn't be too hard to add a bumpstop for the third link. In fact you could limit the center link both up and down to prevent unloading.

 

[Jes]

In fact you could limit the center link both up and down to prevent unloading.

No unloading as the suspension has very little anti-dive, one of the reasons this setup climbs so well.

 

[Matt S.]

It's very tight. I think with the extra torque induced by the portals, the uper arm would have to be stout. As least as stout as Jes' and mine. 1.75" x .120. That's a big upper to try and fit into the narrow space between the bellhousing and tunnel. Now, with a little tunnel massaging, and maybe a very stout smaller diameter upper (1.25" x .375?) it could work.

I love the idea of portals. How about oil pan issues?

CRASH

I know it would have to be VERY stout. Just thinking out loud here... Chromo would be the only thing I would build links out of. Do you think solid stock would be stronger? Machining is not a problem.

To be honest, after hacking the tunnel of the CAT buggy and moding it, it would be a no biggie to do the same to put an arm above or next to the DS.

The thing that is twisting my thoughts is that IF I go through all this. Because of the necessary lack of hieght in the suspension, why use 30"+ arms? I can very easily do what PaulS of Goatman has done. Equal length midarm.

Uptravel is important, but from MY experience with a few buggies I have build and help build are this. 4" to 5" is PERFECT. As most know, limiting uptravel makes the rear or front suspension WORK. My opinion on it is that it is a necessary factor in balanced suspensions.

Oil pan clearances COULD be an issue. I see it only being an issue if I dont offset the differential to one EXTREME. I would think the driver coil would almost have to be half way onto it. I suppose I could use this to get a inch or so of lift. How much travel does a stock XJ have? must be 8"s about. figure 4 up and 4 down?

I cant eliminate uptravel, I need to drive it on the road and jump it in Pismo and race in JV. So I do need some.

Can any of you remeber what CROK did when he built his subframe?
For those that dont, he cut everything from the firewall forward off. And reatached the inner fenders and front facia to it.

I think this would be a really good way to get my stuff all crammed in and make a better and stronger unibody. Just do it out of round stock.

 

[Goatman]

So how will portals work for the go fast and jumping stuff? I can see it for rockcrawling, because of the extra high ground clearance, but would they be on the heavy side for fast work? And what about the leverage when hitting rocks, holes and ledges at speed?

Personally, I like enough up travel. With little up travel, the body is forced to go higher and hence lean more when flexed out.........but I guess a case can be made for the down corner to not drop as much with less uptravel. However, I tend to think that more weight is on the corner that is high than is on the corner that is low, so decent up travel should still be an advantage. A reasonable amount of up travel should tend to make a rig more stable in the rocks, and we all know you need uptravel in the fast stuff.

 

[Goatman]

On my 3 link, with the upper mount high enough to get good angles and proper anti-dive, it gets VERY close to the frame under full compression.........and that's with 7.5" of lift. Of course, the arm angles (and correspondng anti-dive) are relative to the amount of lift, so that might not be much of an issue. But, it definitely is something to consider.

Another thing to think about is that there is quite a bit more compression when jumping and doing the fast stuff, including hitting dunes hard, than there is when articulating. Additionally, the middle of the axle doesn't stuff that much when articulating since one wheel is up and one wheel is down, and the wheels themselves don't stuff as much articulating as when going fast. I get the better part of 2" more stuff at the bumpstop and shock when running quick than when articulating, so further inside of the housing, like where the UCA mount would be, would get even more stuff (when compared to articulating).

 

[Matt S.]

You are probly right on them being to heavy to really work in the fast stuff. These are all just ideas for me and for those who are reading. BUT!!!

I suppose the only way to build a really correct suspension (front and rear) is to have the axles you want under the Jeep.

I can say without doubt that a non portal axle should run the URF kit! SEEMS simple enough and tested. Dont know where else to go with this as of now.

Matt

 

[BrettM]

leafs SUA on portals

 

[Roxtar]

The thing that is twisting my thoughts is that IF I go through all this. Because of the necessary lack of hieght in the suspension, why use 30"+ arms? I can very easily do what PaulS of Goatman has done. Equal length midarm.

That's what I've been thinking while reading this thread. Why go to longarms if you're not lifting. A huge advantage that I see with doing this is the ability to utilize the OEM geometry.

 

[Matt S.]

Here is something I have been pondering lately.

Do you guys think it could be possible to run the lowers on the outside or the "frame"? I have really been measuring and thinking about the suspension and axles.

Here are some thought. Most have changed from my prior thoughts because of some new changes in my finacial ability.

1. Run full size HP60 in front. With the extra width, i could possibly squeez the lowers on the outside. (i am aware of the bad things of full width)

This would be good for me because the ability to run them directly from my cage. As well as having a regular crossmember.

2. Not running a full on 36" long arm. Would there be any adverse effects on say a 27" arm with the URF style? I dont necessarly want to say midarm, but that may be the more correct term.

This would allow me to run the upper off just the inside of the frame.



Not sure how this would work, but i thought I should ask.

 

[Roxtar]

I was thinking that I can run nearly a stock hieght suspension and still obtain 14+ inches of travel.

Would you really get much travel?
Using portals might give you lift but the actual travel would be limited by the stock suspension.

 

[Roxtar]

What about limit the up travel in the middle of the axle ? But still have travel at the wheels.

:huh:

 

[Lawn Cher']

I think he's suggesting a giant bump stop pivot point at the center of the axle.