Rubicon Express Long Arm Replacement?

[Temecula TJ]

There is a practical argument to move to the mid arm because the overall project to eliminate the existing long arm would require new brackets and arms.

I'm not opposed to going with another long arm set up. I realize new brackets, arms etc. are in order but it doesn't make sense to me to go back to SA. I've heard alot about the mid arm so I thought that might be a good alternative to LA especially if it can be done without replacing the belly pan. A new LA would likely require a new belly pan. Seems the consensus is the shocks will have the biggest impact on ride quality. Not sure I would weld anything to my Dana 30. I'd probably replace it with a Dana 44 from Currie.

 

[jjvw]

...

And I’ve learned that saying “outboarding,” assuming folks would go with Fox 2.0 shocks or coilovers, also isn’t the correct way to communicate that message.

Anything surrounding bringing shocks that aren't 5000x or simple bolt on is a potential disaster. I haven't found a reliable way to do it.

 

[MikeE024]

For open desert and more high speed stuff he would benefit from the long arm

What’s the reasoning behind this.

Why would long arm do better at speed over a mid arm?

Shock fade is an issue at speed as shocks begin to overheat so a 2.5 with remote reservoirs is generally a good recommendation.

I haven’t heard anyone complain about shock fade with their Fox 2.0 w/res.

At what level of driving does a TJ need 2.5” shocks? I haven’t heard of a practical scenario where that’s necessary.

 

[jjvw]

I'm not opposed to going with another long arm set up. I realize new brackets, arms etc. are in order but it doesn't make sense to me to go back to SA. I've heard alot about the mid arm so I thought that might be a good alternative to LA especially if it can be done without replacing the belly pan. A new LA would likely require a new belly pan. Seems the consensus is the shocks will have the biggest impact on ride quality. Not sure I would weld anything to my Dana 30. I'd probably replace it with a Dana 44 from Currie.

At the end of the day, you need to come to terms with what you are trying to address with whatever you are thinking of replacing. Typically, we discussing control arm length with regard to suspension geometry and specific behaviors that geometry creates in specific scenarios.

 

[jjvw]

What’s the reasoning behind this.

Why would long arm do better at speed over a mid arm?



I haven’t heard anyone complain about shock fade with their Fox 2.0 w/res.

At what level of driving does a TJ need 2.5” shocks? I haven’t heard of a practical scenario where that’s necessary.

To a certain extent, he isn't wrong about 2.5 Foxes, as they allow for more precise valving and control than a smaller piston. The issue for most is packaging on stock width axles. He doesn't have a solution for that. The rest about arm length and high speed is more ignorant nonsense.

 

[PNW_LJ]

At what level of driving does a TJ need 2.5” shocks? I haven’t heard of a practical scenario where that’s necessary.

@Trevlaw and @NashvilleTJ are two that come to mind that’ve found the limits of a 2.0 shock.

 

[MikeE024]

The issue for most is packaging on stock width axles.

That’s how I understand it as well, so why add a fitment problem (w/ stock axles) if OP doesn’t need 2.5” performance?

I’m not saying he doesn’t have the need btw. I’m am curious to know if there’s a general scenario when moving to the 2.5” does make sense.

 

[mrblaine]

Shock fade is an issue at speed as shocks begin to overheat so a 2.5 with remote reservoirs is generally a good recommendation.

It is apparent you have never tried to tune a set of 2.5's for the rear of a TJ.

 

[MikeE024]

@Trevlaw and @NashvilleTJ are two that come to mind that’ve found the limits of a 2.0 shock.

Good to know thanks. Nashville has a big and heavy rig so I wonder if that’s more of the reason for the need to move up.

I’d like to hear from them regarding what scenarios their 2.0s failed to adequately perform.

 

[PNW_LJ]

There can be a minor insignificant difference in the angle of the upper shock mount depending on when the mid arm goes in, but it has no real impact on anything.

So does this angle difference come from the need to position your shock perpendicular to the lower CA, the angle of which changes when going to a midarm?

 

[mrblaine]

Good to know thanks. Nashville has a big and heavy rig so I wonder if that’s more of the reason for the need to move up.

Big and heavy does not equal go fast. They are mutually exclusive.

I’d like to hear from them regarding what scenarios their 2.0 failed to adequately perform.

 

[PNW_LJ]

Good to know thanks. Nashville has a big and heavy rig so I wonder if that’s more of the reason for the need to move up.

That’s what I was thinking as well.

I’d like to hear from them regarding what scenarios their 2.0s failed to adequately perform.

This was Trevlaw’s ROTM pic. Safe to say most of us aren’t doing this with our TJs

 

[jjvw]

So does this angle difference come from the need to position your shock perpendicular to the lower CA, the angle of which changes when going to a midarm?

Yes, a very small difference in angle that may or may not be noticable to the eye depending how even and precise the prior angle was. The shock does not care, though.

 

[IPerkWVU]

These threads get so theoretical sometimes… OP wants to move on from an old long arm system , has the budget to do it right.

Why not just reccomend a known quality system, I.e the savvy mid-arm and the outboarded fox racing remote resi shocks and be done?

 

[PNW_LJ]

Yes, a very small difference in angle that may or may not be noticable to the eye depending how even and precise the prior angle was. The shock does not care, though.

Thanks, that question has been at the back of my mind for some time now.

@JMT we were talking about exactly this the other day.

 

[mrblaine]

To a certain extent, he isn't wrong about 2.5 Foxes, as they allow for more precise valving and control than a smaller piston. The issue for most is packaging on stock width axles. He doesn't have a solution for that. The rest about arm length and high speed is more ignorant nonsense.

You can tune the 2.5's for a TJ, you won't do it easily with an off the shelf shock though.

 

[jjvw]

That’s how I understand it as well, so why add a fitment problem (w/ stock axles) if OP doesn’t need 2.5” performance?

I’m not saying he doesn’t have the need btw. I’m am curious to know if there’s a general scenario when moving to the 2.5” does make sense.

I forgot about weight for the shock to react against, as Blaine is pointing out.

 

[mrblaine]

These threads get so theoretical sometimes… OP wants to move on from an old long arm system , has the budget to do it right.

Why not just reccomend a known quality system, I.e the savvy mid-arm and the outboarded fox racing remote resi shocks and be done?

Because recommending is not the same as fixing as much BS as there is need to fix.

 

[jjvw]

These threads get so theoretical sometimes… OP wants to move on from an old long arm system , has the budget to do it right.

Why not just reccomend a known quality system, I.e the savvy mid-arm and the outboarded fox racing remote resi shocks and be done?

The recommendation isn't easy to make in good conscience. It isn't simply one modification or one discrete project. Just ask me about a transmission swap or a highline install. None get done without it cascading into a dozen other cats to herd back together.

 

[mrblaine]

I forgot about weight for the shock to react against, as Blaine is pointing out.

Or, and this is a big OR, you spend the time with a good tuner, get some pistons reworked for the appropriate bleed so a good tune can be developed and then spend time with them in the desert to dial it in. Most stop with that effort about the time they pull the shock box off the shelf and open it. It takes time, money, and a good level of committment to make a TJ go fast.

In this case, I'd leave the long arm alone, tune it up, and then get with someone to dial in uptravel, outboarded well tuned shocks and then spend the time and money to figure out how to make them work.