Long arm geometry correction

[TJuser]

Ok so,

I know long arm setups aren't the preferred route here. I picked up my jeep a while back and it had the rough country bolt on long arm kit with Johnny joints swapped on.

I've read quite a bit about these having too much antisquat, resulting in hopping when climbing. As far as I'm aware, the position of the end links on the frame side adjust this, and being as the frame side joints for the upper and lower arms for the rear are level, this results in higher antisquat.

I have some weld-on brackets that the po gave me, which would eliminate the bolt-on portion and give me an extra inch of clearance on the skidplate. The brackets also position one of the end links higher in the rear. Theoretically this should lower the antisquat, right? Just trying to decide if its worth the time to install, or just continue running the setup as is.

 

[Chris]

Ok so,

I know long arm setups aren't the preferred route here. I picked up my jeep a while back and it had the rough country bolt on long arm kit with Johnny joints swapped on.

I've read quite a bit about these having too much antisquat, resulting in hopping when climbing. As far as I'm aware, the position of the end links on the frame side adjust this, and being as the frame side joints for the upper and lower arms for the rear are level, this results in higher antisquat.

I have some weld-on brackets that the po gave me, which would eliminate the bolt-on portion and give me an extra inch of clearance on the skidplate. The brackets also position one of the end links higher in the rear. Theoretically this should lower the antisquat, right? Just trying to decide if its worth the time to install, or just continue running the setup as is.

Yes, that should in theory lower the anti-squat effects.

 

[jjvw]

...

I've read quite a bit about these having too much antisquat, resulting in hopping when climbing. As far as I'm aware, the position of the end links on the frame side adjust this, and being as the frame side joints for the upper and lower arms for the rear are level, this results in higher antisquat.

...

The typical issue with bolt on long arm kits is that they create too little antisquat, resulting in the rear sinking under load, causing the front to get light.

 

[jjvw]

Yes, that should in theory lower the anti-squat effects.

Hypothetically, the goal would be to increase the antisquat effect compared to where he is currently.

 

[The4bangertj]

Ya you’d want to raise the antisquat as your long arm is much lower than 100%. Too low causes the rear to sink which makes for a lighter front end. The lack of separation that makes it such a low anti squat also puts more stress on the brackets. I’ve seen brackets get ripped off because of it.

 

[jjvw]

Ya you’d want to raise the antisquat as your long arm is much lower than 100%. Too low causes the rear to sink which makes for a lighter front end. The lack of separation that makes it such a low anti squat also puts more stress on the brackets. I’ve seen brackets get ripped off because of it.

Now the problem is verifying that 100% is a good number to chase, followed by how to go about chasing it.

 

[TJuser]

This is the rear bracket currently

and this is the bracket to replace it

I haven't had any issues with it hopping much, although I did have it happening once doing a very steep climb up a rock face. Usually I'm pretty cautious on the throttle and let off with any hopping as I don't like broken shafts.

 

[kmas0n]

Are those upper and lower control arms sharing the same bolt?
I've seen this before but not for a long long time. That's going to have a crazy high antisquat value. I've never driven anything setup like that, so I wont comment on its characteristics, but I can't imagine anything good about it. The new brackets are better. Looks like about 5" of separation between the upper and lower link which will drop you AS down significantly. I always end up making my own, because there is no one size fits all.

 

[TJuser]

Are those upper and lower control arms sharing the same bolt?
I've seen this before but not for a long long time. That's going to have a crazy high antisquat value. I've never driven anything setup like that, so I wont comment on its characteristics, but I can't imagine anything good about it. The new brackets are better. Looks like about 5" of separation between the upper and lower link which will drop you AS down significantly. I always end up making my own, because there is no one size fits all.

Yeah they are.

That's what I'd read, somewhere around 160% when typically for an offroader it should be down near 50-75%. To be completely honest, the kit has done me fairly well. Most of our wheeling doesn't involve many boulders, mainly large rock faces and dirt/mud trails, so the lesser clearance of the long arms vs midarms hasn't been much of an issue. It flexes out very well too, I could likely get more out of it with different shocks but it's not my daily and I don't offroad enough to justify putting anything more than necessary into it. I've done some pretty damn gnarly climbs in it that has blown me away with the capability.

 

[jjvw]

Are those upper and lower control arms sharing the same bolt?
I've seen this before but not for a long long time. That's going to have a crazy high antisquat value. I've never driven anything setup like that, so I wont comment on its characteristics, but I can't imagine anything good about it. The new brackets are better. Looks like about 5" of separation between the upper and lower link which will drop you AS down significantly. I always end up making my own, because there is no one size fits all.

Lots of bolt on long arms have this, or very similar, configurations. It isn't much different than a radius arm.

 

[JMT]

Now the problem is verifying that 100% is a good number to chase, followed by how to go about chasing it.

Just input your CG in the calculator. LOL

 

[kmas0n]

Lots of bolt on long arms have this, or very similar, configurations. It isn't much different than a radius arm.

I'm not really up to date on current offerings. But yeah, I think you are right, it's going to behave very similar to a radius arm

 

[jjvw]

This is the rear bracket currently
View attachment 675034

and this is the bracket to replace it
View attachment 675036

I haven't had any issues with it hopping much, although I did have it happening once doing a very steep climb up a rock face. Usually I'm pretty cautious on the throttle and let off with any hopping as I don't like broken shafts.

That bracket would benefit from more vertical separation. The upper is too low on the frame.

 

[TJuser]

I'm not really up to date on current offerings. But yeah, I think you are right, it's going to behave very similar to a radius arm

Yeah I can definitely see that

That bracket would benefit from more vertical separation. The upper is too low on the frame.

Honestly I would 100% fab up my own 4 link setup and stretch, etc. I just don't have enough time with 2 other projects on the go (superduty frame off rebuild, dentside restomod) or the money to be into it seriously enough to stress a bunch about it. Definitely in the future after I've got a house, which are 1.1 mil minimum here, I'd love to get a clean tj or lj and do a proper build. Until then, ive gotta stick with what ive got and if this gives a slight improvement for free, it's better than nothing imo

 

[mrblaine]

Yeah I can definitely see that

Honestly I would 100% fab up my own 4 link setup and stretch, etc. I just don't have enough time with 2 other projects on the go (superduty frame off rebuild, dentside restomod) or the money to be into it seriously enough to stress a bunch about it. Definitely in the future after I've got a house, which are 1.1 mil minimum here, I'd love to get a clean tj or lj and do a proper build. Until then, ive gotta stick with what ive got and if this gives a slight improvement for free, it's better than nothing imo

I strongly suspect your brackets are the ones done by UCF with permission from the company to improve that kit they deliver. Use them.

 

[TJuser]

I strongly suspect your brackets are the ones done by UCF with permission from the company to improve that kit they deliver. Use them.

Very much looks like it, good eye! Was wondering where they came from, I was wondering TMR but yeah, very likely UCF. Awesome, thank you