Setting up links for variable height suspension

[MtnClimber]

Okay maybe that got you interested. So here is the deal.

I have a ORO AiRock air bag system that I want to install a 3 & 4 link suspension on. When driving on the road it has a 3-4" lift and then when off-road it is between 4-5" of lift. So how do I try and setup my links? I know it would be a lot easier for me to switch back to coil springs or coilovers but I need the variable height that the air bags allow me. I am a lower right leg amputee and being able to lower the rig down helps in getting in and out.

This is on a 1997 TJ and I am going to stretch the rear 4-5" and the front 2-3". I know some say this much stretch isn't enough but I have watch TJ's that were stretched out to about 100" WB and felt they worked better off-road and so did those owners.

But what are all these height changes going to do with my numbers? Do I just build it to work at the off-road height and not worry about on the street? I am not wanting to build this with really long arm but more of a mid arm type suspension. I'd like to try and keep my arms 30" or less.
I am running a Ford HP44 in the front and a Tera CRD60 rear. So both axles are high pinion which will help with the driveline angles. I'm currently running a TSL SX 38x12.5x16.5 which once mounted work out to be a 37" tall tire.

For those of you who have not seen the Off-Road Only AiRock system here is some shots of the main parts.
View attachment 85576

This is the computer that does all the controlling of the AiRock system. The plug on the side is for the wiring harness that goes to 4 height sensors, in cab controller and to the battery for power. The one air fitting on the side is the input and from there the air goes out thru 4 ports on the top that control the air in the air bags.
There are also solenoids inside that send the air to the bags.

View attachment 85577

You can see the 4 air ports on the top which go to the air bags that have replaced the stock coil springs. This is the side where the solenoid valves are located.

View attachment 85578

The computer is on this side. It is a active air bag suspension so it will level the Jeep if you have gear in the back or a trailer hooked to the rear. In highway mode which is from 20-50 MPH it will also put air into the airbags to help control body roll. Above 50 MPH it goes into freeway mode it will keep the Jeep level.
Below 20 MPH you are in manual mode. You can adjust the height, lean left or right and so on. In off-road mode your have full control of the air bags and can rock forward where the rear is raised and front lowered for climbing hills. Or rock back where the front is raised and rear lowered for going done steep inclines.
When on sidehills you can lean to the left or right to make it not so bad.

All this is controlled with dash mounted controller.
View attachment 85579

And on the rear of the controller is 3 plugs. The one on the right is used to connect it to the computer. The serial port is for updates. Not sure what the other is for.
View attachment 85580


Here is a video of the AiRock in demo mode going thru it's paces.


I have looked at the Savvy mid arm kit and would love to be able to use it but Savvy and Blaine have spent a lot of time to make this kit work within certain parameters and I don't think from what I have read that it would be a good fit. I wish it was as I feel it is a GREAT suspension kit. Also because of the stretch I am wanting to do I think I would just end up ruining this kit.

Now I know it has been discussed a lot that the 3 & 4 link calculators only give a baseline to go off of. But once the vehicle starts moving all those numbers get thrown out the window. But they do help in the design but until I get it built and try it out there isn't anyway of knowing if it will work. I've been looking at using either the GenRight brackets or the TMR brackets for the links. On the frame end for the lower links I have to use a end that will not allow the tube of the link to roll very much to not damage the height sensors. So either a bushing or a Johnny Joint will work from what ORO has told me. On the axle I can use whatever I want and the same with the upper link ends. This is a height sensor on the Nth Degree longarm.

View attachment 85581

View attachment 85582


View attachment 85583
The complete AiRock system

View attachment 85584
6" lift airbags. They also offer a shortarm 4" kit.


Lets hear your thoughts and ideas.

Wildman - Do you have any better pictures of the AiROCK height sensor mounts that you used with you Nth Degree LA that you could send me as I recently picked up the NTH LA and need to see what the sensor mounts look like.

 

[Wildman]

Wildman - Do you have any better pictures of the AiROCK height sensor mounts that you used with you Nth Degree LA that you could send me as I recently picked up the NTH LA and need to see what the sensor mounts look like.

Off Road Only makes them. I'll try to get you a picture of one in the next few days. I have a few spare mounts.

 

[MtnClimber]

D

Off Road Only makes them. I'll try to get you a picture of one in the next few days. I have a few spare mounts.

Do you have an interest in getting rid of the sensor brackets that you have as I am in the market for some if they are different than the ones I already have (currently have two different sets, 1-set for a TJ SA and 1-set for a JK SA)?

 

[MtnClimber]

Off Road Only makes them. I'll try to get you a picture of one in the next few days. I have a few spare mounts.

I ask as I’m currently in the process of putting together an AiROCKed Nth LA on my LJ and need to figure out if I have the correct brackets and sensor arms for the Nth Degree arms.

 

[Wildman]

Sorry it's been a busy week for me since I got home.

Off Road Only makes and sells the brackets and height sensors. I'd think it would be easier and cheaper to just get the stuff from them. Are you going to get the ECM and controller from ORO? Once I find one I'll take a picture of just the mounting bracket and sensor.

 

[Wildman]

The mount is a little bent but here are the pictures.

 

[MtnClimber]

@Wildman are you willing to let go of the 4 sensor mounts as I could definitely use them?

 

[Wildman]

I'm not at that point yet where I can say I am not going to reuse them with the new suspension I install.

 

[MtnClimber]

I'm not at that point yet where I can say I am not going to reuse them with the new suspension I install.

@Wildman - The sensor brackets you have look pretty specific to the NTH LA Gyro Joints. I do have two other sets of sensor brackets that may work better for your application depending on what direction you go with your new suspension. Also it's only the sensor brackets that I am in need of as I already have the sensors themselves.

 

[Wildman]

Okay I am bringing this thread back up because I have questions and hope I can get some help here.

I am ready I hope to buy parts for my suspension redesign. I have tried to read everything I can the @mrblaine has written about the Savvy mid-arm kit and as much as I would like to use it I don't think it's applicable to my needs.
I'll try to explain my thinking and you all can shoot holes in it.

1) I really don't want to use a fuel cell. I had thought I was ready to go that route but I've decided not to. So I am back looking at the GenRight tanks. Yes I know they won't allow me to push the rear axle back as far as if I went fuel cell. I'm only looking to get 4-5" of stretch out of the back.

2) If I am understanding everything that I have read from Blaine the way he stretches the rear I HAVE to lose the tank so if I am correct then right here is the #1 reason I can't use the Savvy kit.

3) I'm going to try to stretch the front 2-3" using the TNT Customs front stretch kit. So again if I read everything that has been written I can't use the Savvy kit.

Please if I am mistaken someone correct me.

So my questions are this:
Who's brackets do I want to use if I am not using the Savvy kit?
1) TMR
2) GenRight
3) Ruff Stuff
4) Other?

Pretty much decided I'll use Johnny Joints all the way around but then my question is what size shanks for upper and lower joints?
What size tubing do I use for upper arms? What size do I use for lower arms?
I know I need 7 left hand thread & 7 right hand thread joints and tubing adapters.

What other items am I forgetting?
What other advise can others who have done a 4link rear and 3link front offer up?
Going to take the engine to the machine shop next week I hope and get that part of the process started. I have thought about just getting it running and driving again and wait to mess with the suspension until next year but am thinking I'd rather get it all done now.

So fire away and help me figure this out so I am only stumbling thru this with only one eye closed instead of both...

@Wildman - The sensor brackets you have look pretty specific to the NTH LA Gyro Joints. I do have two other sets of sensor brackets that may work better for your application depending on what direction you go with your new suspension. Also it's only the sensor brackets that I am in need of as I already have the sensors themselves.

If you are still interested in the Nth Degree sensor mounts let me know. Also what other mounts do you have? Interested in a trade?
Sorry for the delay in replying.

 

[jjvw]

Why can't you use the Savvy kit? Because you want to do a small stretch? What is the target wheelbase?

 

[mrblaine]

Okay I am bringing this thread back up because I have questions and hope I can get some help here.

I am ready I hope to buy parts for my suspension redesign. I have tried to read everything I can the @mrblaine has written about the Savvy mid-arm kit and as much as I would like to use it I don't think it's applicable to my needs.
I'll try to explain my thinking and you all can shoot holes in it.

1) I really don't want to use a fuel cell. I had thought I was ready to go that route but I've decided not to. So I am back looking at the GenRight tanks. Yes I know they won't allow me to push the rear axle back as far as if I went fuel cell. I'm only looking to get 4-5" of stretch out of the back.

2) If I am understanding everything that I have read from Blaine the way he stretches the rear I HAVE to lose the tank so if I am correct then right here is the #1 reason I can't use the Savvy kit.

Doesn't matter how I do it. The problem is simple physics. Two objects can not occupy the same space without some sort of interference. If you move the axle back it will contact the gas tank. That has nothing to do with how I do a stretch, it has to do with me doing a stretch that moves the axle back far enough that the tank can not live in the space left so it has to move. If you don't want to move the tank, then you have to use a small tank or get less wheelbase. That also has nothing to do with whether or not you can use the Mid Arm.

3) I'm going to try to stretch the front 2-3" using the TNT Customs front stretch kit. So again if I read everything that has been written I can't use the Savvy kit.

Something has to move, where it moves determines what else has to move. The only thing the Savvy Kit limits is how far you put the brackets from the axle. If you are moving the axle back, figure out how far that is, move the brackets on the frame that amount and now you have a stretch with Savvy brackets. I won't do it that way because I like the axle centered in the wheel arch and I will spend more time doing things to make that happen than others will.

Please if I am mistaken someone correct me.

So my questions are this:
Who's brackets do I want to use if I am not using the Savvy kit?

1) TMR
2) GenRight
3) Ruff Stuff
4) Other?

Doesn't matter, pick one and solve the issues they may have.

Pretty much decided I'll use Johnny Joints all the way around but then my question is what size shanks for upper and lower joints?
What size tubing do I use for upper arms? What size do I use for lower arms?
I know I need 7 left hand thread & 7 right hand thread joints and tubing adapters.


What other items am I forgetting?

Uppers only need the 1" shanks. Lowers have to have the 1 1/4" shanks.
2" .250 for the lowers and be aware it isn't as resistant to bending as 2" solid 7075 T-6 aluminum.
1.5" .120 wall for the uppers.
You are forgetting jam nuts. Get FK or similar high quality. The cheap ones wobble on the threads.

What other advise can others who have done a 4link rear and 3link front offer up?
Going to take the engine to the machine shop next week I hope and get that part of the process started. I have thought about just getting it running and driving again and wait to mess with the suspension until next year but am thinking I'd rather get it all done now.

So fire away and help me figure this out so I am only stumbling thru this with only one eye closed instead of both...

Pick your tank, mount it, mock up arms to axle cheaply by taking a jam nut and tacking it to the end of some ERW to push the axle back and cycle it until you figure out where it can live.

 

[Wildman]

Okay the reason I was saying it wouldn't work was becasue my understanding of how the brackets mount the rear brackets are where the frame just starts to bend so they couldn't move back more. And by the way kit is designed adding any length to the arms would defeat the design. Am I not understanding this correctly?
From what I remember in another conversation you had said you cut the frame in front of where the bracket mounts and then add the needed length for the amount of stretch you want.
Since I am trying to push the rear axle back some to get rid of some of the rear over hang but keep the frame so I can mount a tank I don't see how this would work for me.

Why can't you use the Savvy kit? Because you want to do a small stretch? What is the target wheelbase?

As close to 100" as I can get and if I can squeeze out 101-102" I'd be even happier. But I am also fighting the need to have fender flares that cover the tires to be street legal. Which is why I am only trying to go back 4-5" and then push the front forward 2-3".

 

[BuildBreakRepeat]

Okay the reason I was saying it wouldn't work was becasue my understanding of how the brackets mount the rear brackets are where the frame just starts to bend so they couldn't move back more. And by the way kit is designed adding any length to the arms would defeat the design. Am I not understanding this correctly?
From what I remember in another conversation you had said you cut the frame in front of where the bracket mounts and then add the needed length for the amount of stretch you want.
Since I am trying to push the rear axle back some to get rid of some of the rear over hang but keep the frame so I can mount a tank I don't see how this would work for me.




As close to 100" as I can get and if I can squeeze out 101-102" I'd be even happier. But I am also fighting the need to have fender flares that cover the tires to be street legal. Which is why I am only trying to go back 4-5" and then push the front forward 2-3".

For legal stretch flares check out TNT. There is a considerable amount of straight frame where you can push the brackets back. Here is a picture of @jjvw Jeep.

 

[jjvw]

Mine is pushing lightly into the GTS at full bump. A little further back than Blaine prefers. With both ends pushed outward as far as they can go, the wheelbase is 94".

 

[Wildman]

For legal stretch flares check out TNT. There is a considerable amount of straight frame where you can push the brackets back. Here is a picture of @jjvw Jeep.
View attachment 147187

Okay I guess I had some information wrong. I thought I had seen pictures of the brackets installed at almost the point where the frame starts to curve up.

Mine is pushing lightly into the GTS at full bump. A little further back than Blaine prefers. With both ends pushed outward as far as they can go, the wheelbase is 94".

Well it looks like I need to get my rear axle disconnect and then move it back to here I THINK I want it and measure how long the arms would be. It'd be AWESOME if I could make this work.

 

[BuildBreakRepeat]

Okay I guess I had some information wrong. I thought I had seen pictures of the brackets installed at almost the point where the frame starts to curve up.



Well it looks like I need to get my rear axle disconnect and then move it back to here I THINK I want it and measure how long the arms would be. It'd be AWESOME if I could make this work.

It is possible the pictures you were seeing were of a mid arm that had been stretched by moving brackets already, if you were to use a stretch tank and trim the body for clearance, I think the only other issue you would have is needing to notch the frame to fit an upper spring bucket without losing uptravel, or back half kit to remove the frame radius after the axle.

 

[mrblaine]

Okay the reason I was saying it wouldn't work was becasue my understanding of how the brackets mount the rear brackets are where the frame just starts to bend so they couldn't move back more.

No, not where the frame bends up for the rear wheel arch, they are pushed forward into the lateral bend right before the belly skid. You could easily lay out the mount, find the center of the mount, cut the frame there, add a 4" section, and move the frame back that way. Keep the rear of the mount marked if you wish and that will put one end of the frame splice inside the C channel of the mount for extra reinforcement.

And by the way kit is designed adding any length to the arms would defeat the design. Am I not understanding this correctly?

A couple of inches won't hurt. The TJ arms are shorter than I would like by about 2" and you could easily use the TJ Unlimited arms which are 2" longer. That would automatically get you some of what you are after.

From what I remember in another conversation you had said you cut the frame in front of where the bracket mounts and then add the needed length for the amount of stretch you want.
Since I am trying to push the rear axle back some to get rid of some of the rear over hang but keep the frame so I can mount a tank I don't see how this would work for me.

I cut in front when they are already installed. I cut other places when starting from scratch with a new install that includes a stretch.

As close to 100" as I can get and if I can squeeze out 101-102" I'd be even happier. But I am also fighting the need to have fender flares that cover the tires to be street legal. Which is why I am only trying to go back 4-5" and then push the front forward 2-3".

Not saying it can't happen, but I want to see 102 in a TJ with a tank under the back. I've done it, I won't do it again and I doubt that folks will go to the lengths I did to get that.
This is what the top looks like after we customized the crap out of a tank.

That was pushing and tweaking everything possible to get the front and back as far apart as possible.

 

[Wildman]

It is possible the pictures you were seeing were of a mid arm that had been stretched by moving brackets already, if you were to use a stretch tank and trim the body for clearance, I think the only other issue you would have is needing to notch the frame to fit an upper spring bucket without losing uptravel, or back half kit to remove the frame radius after the axle.

Yes my paln was to notch the frame and move the upper spring buckets and if I'm going to try to use a GenRight tank I've got to keep the rear frame.

 

[mrblaine]

Yes my paln was to notch the frame and move the upper spring buckets and if I'm going to try to use a GenRight tank I've got to keep the rear frame.

I'm out.