Project Air Springs ? 97 TJ (large post)

[Daless2]

Air up / Air Down, Effects on Roll Over Potential

In an earlier post I tried to explain some of the considerations in raising or lowering any side of the Jeep (via air pressure in the air springs) when it is off camber or going up or down a steep incline. This is difficult to explain using just words so I did a few simple drawings that may help.

Here is another attempt.

Physically ?Lowering the High Side? (Front, back, left or right) of the Jeep by lowering air pressure in the air springs will always improve (reduce) angles and assist in preventing a roll over.

Where things get interesting is when you ?Raise the Low Side? (Front, back, left or right side). Raising the Low Side can indeed make matters worse, causing an otherwise stable Jeep to Roll.


Level Ground

When the Jeep is on level ground and you raise the rear the entire Jeep rotates around the front pivot point. In this picture the pivot point is the front tire patches on the ground.

When you do this the movement of the C of G (Center of Gravity) is not in a straight line, but rather along an arc in two directions!

Take a look at this picture to understand what happens when the back (or side) of the Jeep is raised by increasing the air spring air pressure on level ground.




Raising the rear with the Jeep on level ground causes the C of G to move Up AND to the Left or front of the Jeep.

Why?

Because it is moving along an arc, pivoting around the front.


Incline

What happens if the Jeep is on an incline (or off camber)?

If the Jeep is on an ?Incline? and you raise the low side, the C of G will also ?rotate? around the front pivot point (tire patch of front tires).

As long as the C of G is Horizontally Higher then the front Pivot Point the C of G continues to rotate along the arc, Up and to the Left (or front of the Jeep).

Here is a drawing to illustrate this:





Severe Incline

The ?RISK? in raising the low side of the Jeeps occurs when the C of G horizontal location falls Below that of the Pivot Point.

IF the C of G is Horizontally Below the front Pivot Point and you raise the rear, the C of G will move UP, AND TO THE RIGHT,or toward the back of the Jeep. This is in the direction of the Vertical Plane of Gravity.

If the C of G passes through the Plane of Gravity, an otherwise stable Jeep will Roll!!!

Why does this happen?

It happens because the C of G is moving on an arc and not a straight line.

Think of the tip of the hands on a clock. They are moving in two directions at all times; Up and Right, Up and Left, Down and Right, or Down and Left. The same movement pairs can and do occur to the C of G of the Jeep while artificially raising and lowering the air springs.

Take a look at this graphically.




If the C of G is below the front pivot point, as it is in this example and you raise the air pressure in the rear spring you can (potential to) cause the C of G to pass through the Vertical Plane of Gravity.

Why?

Because the C of G will move Up and TO THE RIGHT (or rear of the Jeep)!!

This will cause an otherwise stable Jeep to Roll.

Steep inclines, be they forward or backward, and off camber angles that are severe can and will cause the C of G of the Jeep to fall below the high side pivot point. When this condition exists the low side air springs should be aired up cautiously.


The Rules:

Lowering air pressure on the high side of the Jeep can and does always reduce Roll Over angles.

However, raising pressure in the Low Side air springs must be actively managed.

If the C of G is ABOVE the High Side Pivot Point , then raising the pressure in the low side air springs will Reduce Roll Over Potential.

If the C of G is BELOW the High Side Pivot Point, then raising the pressure in the low side air springs will INCREASE Roll Over Potential.
If the C of


I hope I was able to explain this better.

Frank

[Daless2]

It?s been a while since I have been able to add any notes of value to this post. Sometimes life just gets in the way.

I will be updating my Air Spring AiRock system to G-2 (second generation) hopefully in the not to distant future. I thought I?d post a few pictures showing the major component changes in G-2.

Here is the In-Cab Control System



As you can see this is no longer just a set of momentary run switches to control the air pressure in the air springs. This unit, in combination with the new Air Manifold contains Logic and Memory Logic that will enable the ability to set up multiple suspension profiles. A profile can be any height setting that can then be put in memory and then activated simply by pushing a button. I believe 6 or more profiles will be able to be stored.

The new air manifold looks like this




I will also be implementing the tilt sensors that will enable the AiRock system to attempt to manage my Jeep into the most level (Least likely to roll over) position automagically!

I do not have any current experience with the self-leveling, but hope to be able to provide some feedback soon.

Frank

[BlueJeeper]

Frank... too cool. I can't wait to hear how it works out.

[MNClimber]

Hey guys...someone on the local forum here just installed the Second Gen Airrock. He took some pictures, and there is a picture of the sensor that goes on the control arm...

Here's the thread if you're interested:

http://www.tristanroux.com/forum/vie...102&highlight=

Also, I got to go on a trail ride about three weeks ago with the guys from ORO. Great bunch of guys with some awesome Jeeps. Sadly I didn't get to see Steve's Jeep with the gen 2 system in action too much, it was pretty chilly out..no pictures up from that trip yet either...

Mike

[Daless2]

Hi Folks,

I have had the upgrades to my original AiROCK system to bring it up to the current G-2 (Generation 2) system now for four or five weeks. It has taken this long to get it all installed. Not because it is that complex, but rather simply because life kept getting in my way.

Over the next few days I will document and share this installation here. Perhaps some will find it useful. Here are my initial thought and an anouncement to those who may be going to Moab for the Easter Jeep Safari this year.


I find it rare for most things I buy to live up to the marketing hype, let alone exceed my expectations.
This AiROCK G-2 Suspension System is one of the exceptions.

The original AiROCK System exceeded my expectations. Now after upgrading to the new G-2 System I find my expectations have been far exceeded.

The quality, engineering, functionality, materials, and workmanship imbedded in the system are in my opinion "world class" down to the smallest detail.

Any "Bean Counter" could find dozens of ways to cut corners, lowering costs and increasing profits on the AiROCK System. Full use of stainless steel bracketry and hardware, heat sheathed wiring harnesses and waterproof connectors go beyond anything an original equipment manufacturer would use, and beyond what I would expect is necessary. I tip my hat to ORO for their commitment to "over building" the AiROCK system. I really like that!

In my opinion this is a great product that performs ever bit as well on and off road as advertised and beyond.

It has been a pleasure doing business with the folks over at ORO. Soon after I purchased the G-1 system I learned that the new automated G-2 system was fasting coming down the pike. At first I was a bit disappointed, but my disappointment was soon resolved with a phone call from Steve at ORO.

ORO offered to upgrade my G-1 system to the new automated G-2 system for only the price difference between what I paid for the G-1 and the current price of the G-2 system. I thought this was very fair. Once I received the upgraded system components I realized this was far more then fair, leaning very heavily in my favor. I could not be more satisfied with how this upgrade was handled.



AiROCK G-2 System Give-A-Way At Easter Jeep Safari, Moab, UT

Those of you going to Moab for this year Easter Jeep Safari might have an interest in this. I have no problem putting this announcement up as I feel it is beneficial to the Jeeping community, The Red Rock Four Wheeler Jeep Club and the Boy Scouts of America.

Off Road Only will be contributing a complete AiROCK G-2 System to be raffle off at the Boy Scout Dinner during the Easter Jeep Safari weekend in Moab.

In order to be eligible for this raffle you must register and pay your registration fee to the Red Rocks Four Wheel Jeep Club. This club sponsors EJS and is directly charged a fee, by the land management folks, for every Jeep that uses the trails around Moab, even those Jeeps that are not registered. This is a major cost to Red Rocks that really shouldn?t be theirs to bare.

It would be nice if everyone who shows up in Moab for the Easter Jeep Safari weekend would register and pay their fee so that the Red Rock Jeep Club can cover their cost for land usage and we can all carry our share of the burden for the fun we are having.

Perhaps the addition of a raffle for a complete AiROCK G-2 System will encourage more folks to register. And perhaps more folks will then support the Boy Scouts by participation in the dinner.

Someone will win this new AiROCK G-2 System as well as a number of other donated vender products. I hope it?s you!


I will be putting up a lot more in the next day or two.

Have a great night,

Frank

[Daless2]

Hi Folks,

If you have kept up on the earlier parts of this thread you know that the AiROCK G-1 System consisted of a set of four Bilstien 5100 Shocks having built in bump stops, four Identical Air Springs (Only the mounting bracketry varies), a set of Air Hoses, an under hood Air Valve / Solenoid Manifold and an In-cab Control Unit consisting of switches and a display.

This setup allow me to air up or air down any one, or more then one air spring based on what I wanted by manually selecting the cab switches.

The G-2 System is quit a bit different.

While it does allow for the same full manual selection of any or all air springs from the new in-cab control unit, the G-2 System is now fully automated as well.


To upgrade my G-1 to the G-2 system the Air Springs, Bilstein Shocks, and Airlines Remained in place. All else was replace with new sub-systems to include:

(ACU) AiROCK Control Unit (Air Valves/Selonoids /CPU)
New In-Cab Controller
Four Control Arm Sensors
Main wiring Harness
Speed Sensor Harness


Here?s how the installation went with some pictures.


ACU (AiROCK Control Unit)

The original Air Valve / Solenoid Manifold (see below) was an off the shelf industrial unit which was modified for use in the AiROCK G-1 System.




In G-2 it has been replaced with a propitiatory (made by Off Road Only) ACU (AiROCK Control Unit), which incorporates the solenoids, valves, pressure sending units, manifold, and the Computer Brains used to automate the system.

Here is a picture of my ACU installed on the underside of my hood.




I had to make a minor bracket in order to mount the ACU to the underside of my hood. The ACU is designed to mount on the Anti-lock brake plate located on the driver?s side of the engine compartment, next to the master cylinder. I have my hydraulic winch solenoids mounted there so I had to find another location.


The wiring for the new ACU couldn?t be more simple. There is one red and one black wire that get connected to the positive and negative battery terminals. There is also a rather large plug on one end of the ACU. The main wiring harness connects to the ACU at this location. That?s it.


In-Cab Controller

The In-cab controller changes from the manual switch setup which was rather large and bolted to the center section of my dash;




to the new In-Cab control unit which has 6 illuminated touch switches and a two line display to control the entire operation, both automagically and manually.




The new in-cab control unit mounts to the center dash section using 3M trim mounting tape. The bottom of this unit is machined to the contour of the dash for an exact fit on the TJ dash.

The only wiring to be done for the In-cab controller is to plug in a six-wire ribbon cable into the back/ This cable has a modular connector similar to a phone jack or a network Cat-5 cable jack.

The new ACU and In-Cab sub-systems were simple replacements for the original G-1 counterparts. The next sub-systems are new to the G-2 system.



Height Sensors

Each upper control unit on my Jeep now requires a height sensor to be mounted. These sensors are used to determine the angle of the upper control arms relative to all the other control arms and the actual flex limits (extremes) of my Jeeps suspension.

Here are two pictures of the front and rear height sensors, which mount to the upper control arms.

Front



Rear



The sensor brackets and all hardware are made of stainless steel. These brackets are designed in such a way that they bolt directly into existing holes in the frame of the TJ. No drilling is required.

These brackets actually bolt to the Jeep?s ?control arm brackets? where they are welded to the frame.

You can see the linkage, which is hiem joint style on both ends to eliminate any binding in the linkage. The remote end of this linkage attached to a bracket/clamp, which is attached to (around) each control arm.

(NOTE: If you have stock control arms as I do in the upper front, then a simple L-shaped bracket (supplied) needs to be mounted to the control arm. This is done by drilling a 3/16-inch hole in the control arm and mounting the bracket with a SS screw. If you have aftermarket control arms, this linkage mount is a simple bracket that clamps around the control arm.)

Here is a picture of the drivers side front height sensor mounted to my Jeep. Sorry about the poor quality. I think you can see the L-shaped bracket mounted to the control arm, and the linkage connected to the height sensor.




(Sorry, all my pictures of the rear height sensors are too dark to see them. I will try to get better pictures tomorrow.)

Each height sensor has a waterproof potentiometer and a short wire lead going to a waterproof connector. Each is color-coded and plugs into a corresponding color-coded connector on the main wiring harness. It is almost impossible, considering how the main harness is physically set up and the color-coding to plug these height sensors in in any way but the correct way.


Folks I have a lot more to go with this, however it may have to wait till tomorrow. I will put this up now and work on the rest ASAP.

Frank

[Daless2]

Main Wiring Harness

The main wiring harness is a work of art. I wish my Jeep wiring harness was made up to this level of quality. Every connector is waterproof, and the entire harness is clad in a metallic braided heat shield.


Here is a picture of this rather long (about 18 feet) wiring harness rolled up on the table at my favorite coffee hole (The Waffle House).




And here is a much better picture, which I am borrowing, so you can see all the connectors, and I can describe the mechanics of installing this harness.




Someone put a lot of thought and measurement into this main harness. It fits perfectly and connects everything up in a plug ?n play way, BUT you have to install this harness in a certain way. It also helps a great deal if you have someone helping you or you make more then a few trips under and over your Jeep to lay it out properly.

See the section of the main harness labeled ?Main Junction??

This gets placed in the engine compartment right on the center of the firewall. If you do this, everything else falls into place.

The harness leg that contains connectors H1, H3 and H4 is then run on the firewall, above the master cylinder and then down to the underside of the Jeep.

Connector H1 plugs into the height sensor on the front drivers side upper control arm.

The harness is then run to the back of the Jeep along the driver?s side frame rail. The H3 connector then plugs into the driver side rear height sensor, and the remainder of the harness is routed above the fuel tank cross member to get it over to the passenger side rear height sensor. This fits perfectly. All I had to do was cable tie the harness in place.

The harness leg labeled H2 is routed across the firewall to the passenger side and then down to connect to the passenger side height sensor. Again, all it takes are a few cable ties to hold it in place.

Coming out of the main harness is the ribbon cable that plugs into the in-cab controller. It is labeled ?controller? in the picture. I routed this cable through the oval shaped rubber grommet in the firewall and then up through the defroster vent in the dashboard. Then just plugged it in.

The ACU plug looks like a Centronics plug like you would use to connect a printer cable to a printer. This plugs directly into the under hood ACU.

There is a plug labeled ?Speed Harness Connector?. Keep this connector near the center of the firewall. It will be plugged into a short wiring harness that will be run down to the Jeep?s speed sensor located on the transfer case.

The 12 Volt wires connect directly to the battery terminals.

The remaining Aux and Data connectors are not currently being used. One will be used for the Tilt Sensor, which I do not have yet. The others will be used for future additional features that may be added to the AiROCK system later.


Here is a picture of the main wiring harness inside my engine compartment after completing the installation.





Speed Sensor Harness

There is a second, small wiring harness that will connect the main harness to the speed sensor located on the transfer case.

As far as I can tell there is one and only one way to rout this wire. From the center of the wire wall go down on the passenger side of the bell housing. From there route the harness to the back of the Jeep Over the Top of the T-case. I found this almost impossible to route until a friend recommended using a tape steel measure as a snake to pull the speed harness through. Piece of Cake!

The Speed Sensor wiring harness has two connectors on the t-case end. All you need to install it is to unplug the wire currently going to the speed sensor on the T-case and plug the new speed sensor wire in its place. You then plug the original (Jeep) speed sensor wire into the second connector on the AiROCK speed sensor harness. (Life is simple!)

Here?s a picture of the Speed Sensor Harness at the T-case end.




The other end of the speed sensor harness plugs into the main wiring harness inside the engine compartment.



That?s it for tonight folks. Tomorrow I will tell you about automagically configuring the G-2 System to your Jeep suspension and share some of my limited knowledge of how it all operates.

Have a great night.

Frank

[ChrisK]

Keep posting the good stuff Frank. This setup has me thinking.......

Chris

[Daless2]

Completing the Installation

After installing the new ACU, In-cab controller, height sensors and wiring harnesses the next task I had to do was to configure the system.

To do this I needed to start my Jeep?s engine as my compressed air comes from a York OBA system. After pressurizing my OBA system I installed the inline fuse and the entire system came to life.

Everything from this point forward is controlled from the drivers seat via the in-cab control unit. This unit has a group of 6 buttons. During the completion of the installation the UP and DOWN buttons on the in-cab controller are used to reach the appropriate menu choices. There are two tasks that are needed to complete the installation.

NOTE: The In-cab controller will often present you with a choice, something like
Y:Select X:Cancel This means, if you want this choice(Yes) Press the key with the CHECK on it on the In-Cab controller. If you don?t want this choice press the X Key on the In-cab controller.



Seating the Air Springs

IF my (your)installation were a new installation, including the Air Springs, I would need to seat the air springs with 25 PSI of air.

This step is necessary to seat the air springs to the axle perch so that the bolts can be torque down. (I did not have to do this as I already had my air springs installed prior to this upgrade.

All you need to do this is page the In-cab controller, using the Up or DOWN keys until the display reads:

Install AiROCK
Spring to 25 PSI

Then press the CHECK key.

This will bring up a display that will allow you to select any air spring and bring it up to the needed 25-PSI so you can tighten the air springs bolts down.



Calibrating the AiROCK G-2 System

Again using the page UP / page DOWN keys I had to select the screen which says
Calibrate U/D
Y: Select X: Cancel

When I selected the CHECK the AiROCK system started an automated process to calibrate the entire AiROCK Suspension System to the Jeep?s Suspension LIMITS.

During this procedure the ACU Computer (CPU) takes and records reading from all four height sensor during various extreme configurations of the Jeep?s suspension.

The first thing that happens is that all the air springs are air completely down and the ACU Computer records the height sensor values. Then all four air springs are aired up to maximum height.

After Max Height the system airs down to the middle position of the air spring travel and then begins to roll the Jeep to the Left extreme and then the Right extreme.

At each extreme the height sensor reading are recorded in the ACU. Having this data in the ACU enable the unit to manually or automatically control the ride height or ?attitude? of the Jeep.

The configuration process is complete, the Jeep is automatically set to a mid-level point of travel based on the extreme travel of the suspension as just recorded and you can then begin to set ride height preferences for both the Off Road and Highway modes.


Three Modes of Operations

The new G-2 System is automated, yet it still provide 100% manual control, just like the G-1 system when used off road at low speeds. Here is a brief explanation of how these three modes work and how each is automatically transitioned into.


Off Road Mode

My Jeeps always starts out in this mode. Start the engine and it is in Off Road Mode and will stay there until the speed reaches 20 MPH.

In Off Road Mode I have complete control of the suspension. I have the ability to set a specific off road height and then modify it by pressing the touch switches on the in-cab controller.

Here is a diagram showing how some of these suspension adjustments can be made from the in-cab controller.




As I say before, my Jeep is in Off Road Mode until it reaches 20 MPH. Above 20 it automatically transitions into Highway Mode. It will also transition from Highway Mode back to Off Road Mode once the speed drops below 20 MPH again.


Highway Mode

My Jeep is in what is called Highway Mode beginning at 20 MPH through 50 MPH.

In Highway Mode the AiROCK system brings my Jeep to what I have set as Normal Ride Height. This is important because this ride height is where I have set up the steering geometry to be for normal and safe driving.

During Highway Mode (20 to 50 MPH) I have the ability to manually adjust the ride height to a small degree.

Also while in Highway Mode the AiROCK system will automatically air up or air down individual air springs, as needed to compensate for body roll while driving. This is evident when cornering and has a very positive effect on my Jeeps handling. Kinda like adding a virtual sway bar. I like this a lot.


Freeway Mode

The system transitions into Freeway Mode once my Jeep reaches 50 MPH. The Ride Height for freeway mode is the same as that for Highway mode, however, in Freeway mode I have No Ability to adjust the suspension height, and automatic adjustment to ride height to compensate for body roll are minimal.

My Jeep will stay in Freeway Mode until the speed is reduced to approximately 35 MPH, where it will transition back to Highway Mode.




Setting Preferences

There are more then a few preferences that are user selectable from the In-cab controller. Here is a brief list of these preferences and what you can set, display or do with them.

Off Road Height
This is the height you want your Jeep to be set at, as the default when going off road. It is also the height your Jeep will be at from 0 to 20 MPH.

Ride Height
Ride height is the height my Jeep goes to for both Highway and Freeway modes. This is the height I have my steering geometry set for. In my case I set the Ride Height for something lower then the Off Road Height simply because I do not need higher Off Road height for tire clearance while traveling above 20 MPH.

This ?lower? Ride Height makes my Jeep more stable at high speed and improves on-road handling considerably. I like a lot this too!


Speed Calibration
The AiROCK G-2 System comes from ORO fully calibrated for speed sensor on the Jeep TJ. This function is only used if the system is installed on another vehicle. If you have a TJ you will not use this function.

If you need to use this function it is rather simple. You enter the function and drive your vehicle to MPH. When you reach 20 MPH you press the check button on the in-cab controller. Then you bring the vehicle up to 40 MPH and once again record this speed in the ACU by pressing the Check button. That?s it, the vehicles speed is then calibrated into the ACU.

Once again, if you have a TJ, you don?t have to do this.


Service Mode
Service mode is used to lower the air pressure in all four air springs to 35 PSI. This enables the Jeep to be safely lifted on a Frame Hoist for service.


Egress
If you want you can set an option that will automatically lower the Jeep whenever you turn the ignition key off, making it easier to get in and out of. This is a simple menu selection choice.


Set to 0 PSI
This function does exactly what it says, it brings the entire system down to 0 PSI to enable your ability to safely service any part of the system.


Button Menu
This feature allows you to select or assign what functions you want performed by the in-cab controller touch buttons. You can set individual and multi-press button function from here.


Show Installed Options
This menu selection will display what options and preferences you have set for the AiROCK G-2 System. It will also indicate if you have the Tilt Sensor installed.



I am sure I will e putting up a few more notes on this over time. I hope some of you find this info useful. Later I will try to address any comments or questions that I can.

Have a great day folks.

Frank

[Darrell C]

Frank,

Great write up. Very detailed and informative. You have piqued my curiosity with this system.

Like others, I'd also be interested to hear your impressions of both on-road and off-road driving...when you get to that point.

One question, if I may: how are you managing the shock situation? With that much suspension travel, I would think the shocks would limit either suspension compression or extension...in essence not allow full travel to the extreme limits of the air suspension system.

Again, great write up.

Darrell

[Daless2]

Originally posted by Darrell C
Frank,

Great write up. Very detailed and informative. You have piqued my curiosity with this system.

Like others, I'd also be interested to hear your impressions of both on-road and off-road driving...when you get to that point.

One question, if I may: how are you managing the shock situation? With that much suspension travel, I would think the shocks would limit either suspension compression or extension...in essence not allow full travel to the extreme limits of the air suspension system.

Again, great write up.

Darrell

Hi Darrell,

The AiROCK Suspension comes with a set of custom-built Bilstein 5100 shocks. The custom part is that they have a set of build-in bump stops. The AiROCK system eliminates the stock bump stops entirely. So far this has not be a problem for me at all.

The rest of the shock appears to be right off the shelf, correctly sized, 5100 for a 4-inch lift. (I would rather these be the Edelbrock IAS shocks and I am working on getting them to fit with some custom bump stops.)

I do not have the worlds most sophisticated suspension system. It is a five-link rear with only adjustable upper control arms and a relocated track bar. The front has adjustable lower arms and a Currie track bar.

In my case I find these shocks work great with the air springs and my suspension travel limits. On the up travel the bump stops are just touching as they should with 35 inch tires on and just prior to the limits of the suspension being reached.

On the down travel my suspension linkage reaches it max travel before the shock bottoms out. There is about 1/2-inch of additional travel left in the shock before it would bottom out.

Like I said, for what I have this is working great. If you had a setup with more flex to it this may be a problem but I don?t know for sure.

I have had the AiROCK system installed on my Jeep since October of last year so I do have some off road experiences with it (not enough). So far I really like it. It is so soft, and gets my jeep into flexed positions in a way that sometimes I cannot even feel it happening.

What I am really looking forward to is the ?Tilt Sensor? which is coming soon. My motivation for doing all this was to better be able to control rollover angles. I am very pleased with the additional angles I can ?buy? via this system but now want to have these angles automated with in reason.

I should have the tilt sensor in a few more weeks. I?ll let you know how that works out.

Have a great evening,

Frank

[William]

The new control pannel makes it a lot less intimidating. Much prefferable to the toggle switch style that's out there. Honestly, the toggle system looked to be too much for someone...

Well, shoot, for me, I don't even put my GPS in the Jeep because I get distracted.

So the new controller seems to be pretty cool.

I'm wondering, what the projected cost of this sytem is?

And do you set drive line angles for the highway mode I guess?

And do you find that highway handling at the outer limits, that you could get some kind of lift outboard side of a turn?

Will they offer something besides billsteins, or do the airbags' softness make up for the stiffness of billsteins?

[Daless2]

Hi William, how are you doing my friend?

Yes I agree, the new In-cab controller is a lot nicer, and it certainly takes up a lot less real estate.

This system is pricey, about $2,500 plus cost for an OBA system and any other suspension components needed to a 4 (or 6) inch lift. In my case that was limited to a Currie front track bar and a relocation bracket for the rear. I already had adjustable rear upper control arms and adjustable front lowers.

My system is designed for a 4-inch lift, but in reality I only set it up for 3-inches of lift. I just don't need any more for my 32-inch tires. I set my drive line angles for the 3-inches of lift. The rear pinion is within 2 degrees this way.

When the system goes into Highway mode it lowers to just under 2 inches of lift. At this height the rear pinion angle is 0 degrees, which obviously is perfect for high speed travel.


Yes the air springs adjust themselves via the ACU when traveling at highway speeds and cornering. It works very smoothly yet it sounds like a mini ARB locker going on and off and on in 1/4 second increments. Part of the sound issue is were I have the ACU mounted on the bottom of my hood. I may run an exhaust hose to relocated the exhaust port under the Jeep if this noise starts to bother me more.

In a turn at speeds over 20 MPH the outboard side of the Jeep gets some additional air pressure while the inboard side of the turn gets a decrease in pressure. Then when the turn is completed everything again self adjusts. It actually is a very smooth and quick transition.


The Billstein seem to work OK, and in truth becuase of the requirement for a built in bump stop I am stuck with them for the time being.

I have taken them off and put my old Edelbrock IAS shock on and MUCH preferred them. The difference in on road handling was significant. I did this only to test it and found I could move my Currie AR links all the way to the highest off road setting and still the Jeep performed better in cornering then with the Billstein Shocks and the more conservative AR settings. I had to put the Billsteins back on for the bump stops, but I'm working on a set of Edelbrocks with built in bumps stops now.

I can't say the Billsteins are "hard" at all, and I think that is becuase of the inherent softness of the air springs. I would just prefer the Edelbrock IAS shocks. They work great off road and on road they clearly control body roll on my Jeep much better.

Have a great day

Frank

[TJeeper]

I was wondering how interactive the height adjustments are. When I load up my Jeep for a long trip, and put about 400 lbs in the back, it sags about 3 inches, and gets real tail happy. Will the system recognize the rear is lower and adjust accordingally, or is the normal height just set, and you have to adjust it manually?

Note: I posted this on JU, before I realized this would probably be a better place.

[Daless2]

Hi Patrick, (TJeeper)


Yes all four air springs will compensate automatically for weight placement, or weight shifting in the Jeep dynamically and bring the Jeep back to the ride height you have selected.


The way it works is actually quite simple. After installing the new G-2 system the microprocessor is calibrated to read and record the sensor positions of the suspension at the extremes of travel. This is done while by cycling the air springs and suspension to their fullest minimum and maximum extent of travel.

In other words, the air springs are aired up to maximum, and the control arm sensors (one on each of the four upper control arms) are read and the resistance value recorded. Then the system is aired completely down and the sensors read and recorded. This is followed by airing up only one side, then airing up the other side, then only the front, and lastly only the back.

The microprocessor then has the resistance reading from all the sensors and using these readings as reference points, the microprocessor knows (relatively) exactly where the suspension is at all time.


Once the min/max suspension travel readings are recorded during this calibration process, the system then prompts you to set the "Off Road Height" and the "Highway/Freeway Height". This is where you manually (one time) set the height you want your Jeep to be at while going off road, and the ride height you want while traveling over 20 MPH (Highway/Freeway height.)


Once you set these heights, the system will maintain these heights automagically.

In your example, adding 400 # of stuff to the rear of the Jeep would only be noticeable in ride height with your Jeep sitting in the driveway with the ignition system off. As soon as you start it up the system will automatically level your Jeep and bring it to the Off Road Height you have set it at.

The same thing is true while driving the Jeep.

The system will maintain (within a reasonable degree of accuracy) a level ride height by airing up or airing down individual air springs as you drive. This is particularly evident when driving under 50 MPH. You can hear the air valves controlling the air springs as you go around corners. (Sounds like a ARB air locker going off rather quickly, but faintly in the background.) This is compensation for weight which is constantly shifting as you drive. Particulalary while cornering. It is actually a very nice feature and improves the high speed handling of my Jeep dramatically.


Hope I have explained this adequately,

Frank

[ChrisK]

Great explanation Frank. This then begs the question that if it adjusts automatically, does it do it fast enough that you could run without swaybars?

Chris

[TJeeper]

Frank-

Yes, your explanation was more than adequate.

Thanks-

[Daless2]

Originally posted by ChrisK
Great explanation Frank. This then begs the question that if it adjusts automatically, does it do it fast enough that you could run without swaybars?

Chris

Hi Chris, Good Question!

Not sure I know the answer to it though. I would think not, but I do have a bit more info to go with that thought.

The auto air up/down of the individual air springs is rather fast, but it is also somewhat digital. Meaning the air solenoids open and close rapidly and repeatedly. How much actual air is going in (or out) during each cycle is unknown to me. I would think without the benefit of the sway bars the air cycling needs would be greatly increased.

For my set up I have the Currie AntiRock in the front, and stock sway bar in the rear. When I installed the first AiROCK system I had to swap out my Edelbrock IAS shocks for the Billstien 5100's which have the built in bump stops needed for the AiROCK System. I found the handling around corners to be more "Leany" then what I was accustom to. I wasn't sure what the cause of this was. So I did some testing by swapping the Edelbrock shocks back in and testing different setting with the AntiRock sway bar.

With the Edelbrock shocks I could put the AntiRock sway bar in the softest setting and it still handled better around corners then the Billstien shock did with the AntiRock set in the middle position.

Since putting the AiROCK G-2 system in, I can now run the AntiRock (and the Billstiens shock) in the softest setting and do not notice any perceived difference in on road handling.

Obviously the system is able to compensate for the extra or easier movement allowed when the AntiRock is in the softest setting, but I don't know if it could react fast enough to do so without the sway bar connected at all.

I would think the speed needed would also be a function related of how much reserve air is available as well. In my system I have 2.5 gals. of reserve air available plus the York OBA compressor.

Perhaps this weekend I can do a bit of seat of the pants testing. I'd like to know myself.

Frank

[ChrisK]

Dang I wish I had the coin for this system. The more I read about it, the more I like it.

Chris

[Daless2]

Recently I had the opportunity to install a new AiROCK ACU with BETA Test Code in my 97 TJ.

I thought I would post up a few notes of what is about to be coming down the pike. (Yes indeed I do have Steve?s permission to share this with you.)



The New ACU looks on the outside to be exactly like the original unit. All the changes are inside in the code.

Here are some highlights or improvements and new features as I see them.


New Menu Tree

The In-Cab control unit has a completely new menu tree to it. In my opinion this menu tree I far more intuitive to use then the original design. (You really don?t need an instruction book to figure it out.)

Pressing the up and down arrows causes you to select a menu choice,

and then,

choosing the right or left arrows causes you to perform a sub-function menu operation.

This works a lot like my Garmin GPS menu/button interface. Now that I think about it, it work even more like the interface on my Nokia cell phone. I really did kinda fall right into using it.

The display unit also prompts you much more nicely as to which buttons you need to press to do which things.


KUDOS to Steve and crew for taking the customer feedback positively and letting it override the M.I.T. engineering at least for the ?end user interface!?



Off Road to Highway Mode Transition

The transition point from off road mode, where the driver has complete manual control over the system, to Highway mode where manual and automatic control takes place has been changed from 25 MPH to 30 MPH.

While this has never seemed to be a problem for me I believe some folks thought 25 MPH was too close to a shift point on their Jeeps. Thus the change.



Modes of Operations

There are now two modes, Off Road 1, and Off Road 2, and each of these modes comes in two flavors, Standard Preset Maximum, and Continuous Mode.

I really like this.

Now in order to change from one mode to another there is no need to go into the menu system at all. Simple press the X button at the same time as the Right arrow and you switch to Off Road 2. To get back to Off Road 1 all you do is press X and the left arrow and you are right back to Off Road 1.

Regardless of what mode you are in, 1, or 2, you can enter the ?Continuous? mode by pressing the X and Down Arrow, and exit Continuous mode by pressing the X and Up Arrow.

This is instantaneous and can easily be done at any time.

In Continuous mode, any operation you select with the control buttons will be performed for as long as you hold the button down.

Let the button up and it stops instantly.

As I said I really like this.

I like being able to get to it fast, and be able to manually perform any function the AiROCK system is capable of, to whatever degree I WANT IT TO GO! (Read that, Full Driver Control, made much easier and intuitive to perform on the fly (or on the Rocks!).)



New Air Management Algorithm

In the original ACU the solenoids cycle on and off (digitally) until an operation is performed. This is particularly evident when traveling at speed in the Highway or Freeway mode and the system is automatically compensating for body learn and weight transfer when going around corners.

Those of you that have this system know what I am talking about when I say you here the ?machinegun like sound? coming from the under hood ACU. This sound is caused by the solenoids operating the air valve in an On/Off pattern until the proper pressure is reached for the giving condition.

The new air management system does this in a much smoother, analog sort of way using logic control.

The solenoids no longer cycle on and off continuously.

The ?duration? of a single on/off cycle is calculated and the solenoid then performs that function. Suspension adjustment seem much smother and far faster with this new air management algorithm and logic control. This also causes a continuous Hisssss type sound.



Suspension Lock Control

When in both Highway and Freeway modes the In-cab control unit presents you with an option to ?lock? the suspension at the current height.

In effect this is turning off the automatic adjustments when you select this.

The ?lock? mode only remains active until your speed drops down below 30 MPH. At that point, lock mode is canceled and would have to be re-selected by pressing a single button again. (Left Arrow Button.)



Power Management

I do not have any first hand info to share with you in this change, but I do know that changes have been made to reduce power consumption (draw) from the Jeep?s battery when not running. I never had an issue with this so didn?t have anything to compare performance improvements against.



Diagnostics

The new code in the ACU comes with a complete set of diagnostics.

I am not going to tell you how to get into this diagnostics, as that is not my information to share. However please know it is designed to be able to help a customer out should a problem ever occur.


Simply call ORO and they will tell you how to get into it. Then be prepared to read a lot of 1?s and 0?s over the phone to them so they can tell you what the cause of the problem is.

From what I have seen in doing some pre-release testing of the new ACU code, the diagnostic feature worked flawlessness.



Summery

I have always been very pleased with the AiROCK suspension system, and I am even more pleased with what is coming down the pike in improvements.

What I have in my Jeep right now is a pre-production release that in my opinion is indeed ready for prime time. However Steve tells me he is not satisfied with the level of testing. He will be finishing up the final testing efforts soon.

It is my understanding that the Enhanced ACU?s will be going out, on an exchange basis, to all existing AiROCK customers once the code is finalized, for a ?Nominal Shipping and Handling? fee. I don?t know what this fee will be, nor do I know for sure if that is how this will be handled.

For those who have this AiROCK System I would give Steve and crew another month or so before expecting an email from ORO explaining the exchange program. I am confident it will be worth the weight.

Have a great evening folks.

Frank