Rear Air Bags for Dummies

[66-PMD-GMC]

OK,
I have been searching and searching through the forums for pics and how to instructions, so to speak.
I am not into frame scraping lowered trucks and this truck is not going that route but I have zero experience with airbags.
Here is what I am doing.
This truck will be for my wife.
She wants it to sit lower than stock, have fat hides out back and have a "lopey" idle like my trucks and cars have.
What I have,
Stock frame 63 Chebby so I have coils now. I am squeezing 18.5" tires under this truck and the wheels I found will have the tires rubbing on the springs. I would like to give her a decent ride quality and get her to handle so coil over shocks are pretty much out.
My neighbor has talked a lot about air bags with shader valves and it sounds like an option that could work well. They are apparently small enough in diameter to clear the side walls so here are my questions.
1-Photos of installations?
2-suggestions on what to use?
3-Best place to find parts?
I am not interested in C notching or adjustable ride height. I want to set this and go..... simple and minimum maintenance.
I am also using the 3" wider fenders on a step bed.
I know there is a mountain of people in the know here... any words of wisdom?

[SCOTI]

Originally Posted by 66-PMD-GMC

My neighbor has talked a lot about air bags with shader valves and it sounds like an option that could work well. They are apparently small enough in diameter to clear the side walls so here are my questions....

A properly spec'd air bag that is installed in place of the coils will be similar in diameter as the coils. I'm wondering what bag he was referring to?

As far as installing them.....
http://www.67-72chevytrucks.com/vboa...d.php?t=129463

[BR3W CITY]

If he's referring to a narrow diameter bag, I might assume something like a Firestone Sleeve bag or similar. They don't bellow out like many bags; which is both good and bad. It maintains a narrower profile to squeeze in those bigger tires without rubbing. They often aren't considered as strong, but take into consideration the usag for what you would want, they may work out well.

You could also run a "helper" air bag setup, the kind summit or the type would carry.

[tincan1966]

My first air bag suspension was made up from an Air-Lift over-leaf kit from Amazon.com, for about $250 shipped to my door. You can modify the plates that come with the kit, and it has air lines and schrader valves.
The bags are very similiar to the D2600 style bag alot of people seem to use, and about 1-1 1/2 smaller diameter than the stock rear coils
Just my 2 cents worth.

[66-PMD-GMC]

Originally Posted by SCOTI

A properly spec'd air bag that is installed in place of the coils will be similar in diameter as the coils. I'm wondering what bag he was referring to?

As far as installing them.....
http://www.67-72chevytrucks.com/vboa...d.php?t=129463

As I said, I have no airbag experience. As far as "properly spec'ed" air bags, The bed so far is a little over 100 lbs lighter than a stock bed. Not running a wood floor.
Who or how is an airbag spec'ed to a project?

[66-PMD-GMC]

I have to get out there and bolt the wheels on to take a look but the sidewalls are about a 1/4" from touching the springs installed.
Any movement of the frame will have the tires in contact things they shouldn't.
I also need to check the trailing arm clearance.
I am trying to use parts I have but I may need to rethink the tire selection possibly.
I will try and get a couple photos to post but I thought bags smaller than the springs would be the answer.

[BR3W CITY]

Bag diameter and type is dependant on 1. load 2. available room 3. amount of travel 4. amount of air you have available.

In a "play" bagged setup, where you intent to drop and lift alot, it helps to run as much bag as you can fit.
In your situation, the bag wouldn't be the "main" suspension component, as you'd still be keeping either the spring (and running the bag as a "helper) or keeping the shock for dampening. The sleeve-bags are fine for that. Your other option could be something like a Shockwave,which is sort of like an air-can. Its half shock and half bag.

[SCOTI]

Originally Posted by BR3W CITY

In your situation, the bag wouldn't be the "main" suspension component, as you'd still be keeping either the spring (and running the bag as a "helper) or keeping the shock for dampening. The sleeve-bags are fine for that. Your other option could be something like a Shockwave,which is sort of like an air-can. Its half shock and half bag.

From what I read in his initial post, the intent is to replace the existing coil w/a bag. The 6"-6.5"/~2500# bags are typically what is spec'd for a 63-72 truck arm application (ex: Firestone 6781 3" min height, 4.5-5" @ ride height, 7" max height, 6.5" dia).

The F9000 series Firestones could prob get the job done since it doesn't appear that this thing is going to be a work-horse (F9000 4.5" min height, 9-9.5" @ ride height, 12" max height, 5" dia).

The question will be the difference of installed ride heights & if things can be dialed-in to where he wants it.

[markeb01]

I know very little about bags, but saved this thread in case I ever wanted them in the rear of my truck:

http://67-72chevytrucks.com/vboard/s...d.php?t=480726

[66-PMD-GMC]

Originally Posted by SCOTI

From what I read in his initial post, the intent is to replace the existing coil w/a bag. The 6"-6.5"/~2500# bags are typically what is spec'd for a 63-72 truck arm application (ex: Firestone 6781 3" min height, 4.5-5" @ ride height, 7" max height, 6.5" dia).

The F9000 series Firestones could prob get the job done since it doesn't appear that this thing is going to be a work-horse (F9000 4.5" min height, 9-9.5" @ ride height, 12" max height, 5" dia).

The question will be the difference of installed ride heights & if things can be dialed-in to where he wants it.

This truck will be a fun driver for my wife.
The heaviest thing that will see the inside of the bed would be groceries at best.
She likes the snap on bed cover so knowing her, not even daylight will see the bed floor once done.
I am modifying a 67-72 steel floor to work with the step side bed and sit on the 63 frame.
She wants her ride height lower than stock. I will establish the rear height and match the front to the rear. I would like to see a slight rake in the stance.
Putting one wheel on I was right, it is too close to the spring (about a 1/4") so if I could get the springs, bags or whatever I use even with or inside the frame rail I will be golden. I can see I will also need to fabricate some kind of sway bar also.
There is way more movement in all directions in that rear suspension than I though there would be.
The panhard rod is nice but I think I will build a custom adjustable unit since the ride height is dropping 3-4" from where it is now.

[66-PMD-GMC]

Originally Posted by markeb01

I know very little about bags, but saved this thread in case I ever wanted them in the rear of my truck:

http://67-72chevytrucks.com/vboard/s...d.php?t=480726

Thanks for the links...
The "dragging steel" photo is WAY lower than I want to go. that orange truck is slightly higher than the Mrs. wants...

[66-PMD-GMC]

Originally Posted by SCOTI

A properly spec'd air bag that is installed in place of the coils will be similar in diameter as the coils. I'm wondering what bag he was referring to?

As far as installing them.....
http://www.67-72chevytrucks.com/vboa...d.php?t=129463

Just caught that link you posted... thanks.. the more info the better

[66-PMD-GMC]

OK, I have an idea.
Does anyone make stock trailing arms that are "moved in" on the diff. side?
I really wanted to minimize fabbing up stuff on this truck but I could build a cross member to carry the load and just move the suspension in 3 inches.
Yes? No?

[66-PMD-GMC]

Originally Posted by 66-PMD-GMC

OK, I have an idea.
Does anyone make stock trailing arms that are "moved in" on the diff. side?
I really wanted to minimize fabbing up stuff on this truck but I could build a cross member to carry the load and just move the suspension in 3 inches.
Yes? No?

Forget the above... I just got back from checking out parts etc.. etc.. and I am going to stay with the stock configuration suspension and replace the coil springs with air bags. Relocate the bump stops and use the room I have available. I never knew there were so many airbag options.
I don't like the rear sway-bar setups I have seen so far at the parts store.
Again, this is not going to be fully adjustable "air ride". I am going to set it and go, may use coil over heavy duty shocks, want it stiff and nice to handle but not ride like a buckboard.
Oh, and one other thing. I mounted the wheel/tire combos and the tire nearly touches the springs on one side and has a little less than a 1/4" clearance on the other side.
I'll bet this Lil shortbed dog legged down the road when it was drivable.
Thanks for the help so far everyone

[SCOTI]

Originally Posted by 66-PMD-GMC

Forget the above... I just got back from checking out parts etc.. etc.. and I am going to stay with the stock configuration suspension and replace the coil springs with air bags. Relocate the bump stops and use the room I have available. I never knew there were so many airbag options.
I don't like the rear sway-bar setups I have seen so far at the parts store.
Again, this is not going to be fully adjustable "air ride". I am going to set it and go, may use coil over heavy duty shocks, want it stiff and nice to handle but not ride like a buckboard.
Oh, and one other thing. I mounted the wheel/tire combos and the tire nearly touches the springs on one side and has a little less than a 1/4" clearance on the other side.
I'll bet this Lil shortbed dog legged down the road when it was drivable.
Thanks for the help so far everyone

Get a long adjustable Panhard bar from Porterbuilt or No Limit & you should be able to easily get the rear centered & not have to worry about excess movement during the cycling of the suspension.

If the bags are used @ the recommended ride height, you should only need quality gas shocks. Outside of that realm & you're band-aiding something so targeting the bag height should be the priority.

[66-PMD-GMC]

Originally Posted by SCOTI

Get a long adjustable Panhard bar from Porterbuilt or No Limit & you should be able to easily get the rear centered & not have to worry about excess movement during the cycling of the suspension.

If the bags are used @ the recommended ride height, you should only need quality gas shocks. Outside of that realm & you're band-aiding something so targeting the bag height should be the priority.

I appreciate the advice.
Having no experience with air suspension other than putting shocks on my wifes Navigator, my familiarity with the type of ride air suspension is minimal.
The navigator squats to one corner on hard turns. I am not impressed with its suspension.
My 30 year old son struggles with leaks on his Lincoln town car.
I consider quality shocks highly important and thought the coil over route might stiffen up the "roll" on the back of the truck.
I like to toss as many ideas around before I start spending money on a plan.
Still building that plan.

[SCOTI]

Air springs need to be isolated 'per corner' or you'll experience that body roll. It is usually also much worse vs steel springs because of the inherent natural tendency of the air to follow the path of least resistance if the corners are not isolated.

The right bag @ the spec'd height w/good quality shocks can ride/drive as good as or better than a 2011 vehicle.

[66-PMD-GMC]

Originally Posted by SCOTI

Air springs need to be isolated 'per corner' or you'll experience that body roll. It is usually also much worse vs steel springs because of the inherent natural tendency of the air to follow the path of least resistance if the corners are not isolated.

The right bag @ the spec'd height w/good quality shocks can ride/drive as good as or better than a 2011 vehicle.

I figured that the twin shrader valves were to keep the two bags separate.
I ran into a guy that has what I think I need on his truck.
Ran into him at the local Saturday night car show and his 67 had air bags that are just about even or slightly wider than the frame but aren't nearly as wide as the stock springs that stick way out.
Gave him my number and he is going to call me with the part number and manufacturer.
I am going to set the frame on jack stands with no springs at all and measure the rear space where the bags will sit and see if his will do the trick once I have the specs.
Still looking for an aggressive rear sway bar setup for the 63 trailing arm setup.
I have an 1 1/4" on the front now.

[fleetsidelarry]

for a sway bar option, you might look into the camaro/firebird swap:

http://www.low69cst.freeservers.com/CamaroBar.htm

these bars are available up to 23mm OEM I believe (probably bigger aftermarket) which should be plenty for the rear. might be a clearance issue with your tires (one member on the forum (Losthope maybe?) relocated his to mount to the trailing arms which might solve that issue).

as SCOTI mentioned, get as long a panhard bar as you can to limit the side movement. you can't eliminate it unless you do watts linkage. it sounds like you're up to fabbing mounts, etc so you're not limited to the short panhard like's on my '66.

[mavdog32]

Ok so for you guys running bags, how do they perform with a high HP motor? I am in the middle of my build now and am trying to decide if i want to run bags or coil overs. I like the bags and will go with them if they hold the load of a hard launch well.

TIA

[66-PMD-GMC]

Originally Posted by fleetsidelarry

for a sway bar option, you might look into the camaro/firebird swap: these bars are available up to 23mm OEM I believe (probably bigger aftermarket) which should be plenty for the rear. might be a clearance issue with your tires (one member on the forum (Losthope maybe?) relocated his to mount to the trailing arms which might solve that issue).

as SCOTI mentioned, get as long a panhard bar as you can to limit the side movement. you can't eliminate it unless you do watts linkage. it sounds like you're up to fabbing mounts, etc so you're not limited to the short panhard like's on my '66.

I see that there will definitely be clearance issues using that sway bar.
I had to cut the bump stops off and pretty much clean the outside of the frame rails completely to stuff these hides in.
I also need to take some fleetside wheel houses and narrow then a bit to use inside the step bed.
I am at a loss of why the emphasis on the longer pan-hard bar.
Once the springs are out of the way I will have a good 1 3/4" - 2" minimum clearance between the sidewalls and anything else that moves independently of the axle and tires.
Also, I think i might reiterate that I am not building this to go up and down like a lowrider. Once the ride height is set, thats it.
I drove a 10 wheel dump truck with airbags.... inflated was the ride height on that truck and no air to dump.
I was thinking kind of on the same line with the wifes 63, setting the pressure to get the correct ride height and keep it there. Always. There should be no lateral movement except normal putting around especially if I make sure the pan-hard bar is parallel to the diff. at ride height.
Is my thinking wrong? As I said, I know nothing about air-ride systems...

[66-PMD-GMC]

Originally Posted by mavdog32

Ok so for you guys running bags, how do they perform with a high HP motor? I am in the middle of my build now and am trying to decide if i want to run bags or coil overs. I like the bags and will go with them if they hold the load of a hard launch well.

TIA

I see guys at my local dragstrip running air bags but have never really asked any hard questions of them or about them.
I see the major issue of getting power to the tires and the tires to stick with trucks as weight transfer.
There is no weight in the back of these trucks (I mean for transfer here, I know the bed weighs something)
When I had the HO Pontiac motor in my 66 briefly, all it did was roast the tires.
I couldn't get it to hook up for nothing.
It is a long bed GMC with leafs so I really didn't expect anything anyway.
But what this 63 will do as a short bed and trailing arms/air sprung... who knows??
The motor that was in the 66 is a 440 inch 600+ hp Pontiac torque monster..
The wifes 63 will get a 360ish inch Pontiac making a little more than 380 hp and will be used on cruise nights etc..

[mavdog32]

Dont get me wrong, this isnt a competition truck but I will have it at the strip every once in a while. Its mainly going to be a cruiser with the occasional mustang in the rear view Motor is a turbo 5.3 running around 650-700 on pump gas. I already planned on running the tank behind the axle to get some weight back there. Also going to keep the wood and anything else to add weight back there. I just picture the bags collapsing a bit more than I would like under hard accel and wanted to see if this holds true from people who have them.

BTW this is a 54 chevy

[fleetsidelarry]

Originally Posted by 66-PMD-GMC

I see that there will definitely be clearance issues using that sway bar.

I'll see if I can find the other thread or link that shows the relocation of the camaro bar to the trailing arms. the bar is turned around and moved forward, perhaps enough to clear the tires

Originally Posted by 66-PMD-GMC

I am at a loss of why the emphasis on the longer pan-hard bar.
Once the springs are out of the way I will have a good 1 3/4" - 2" minimum clearance between the sidewalls and anything else that moves independently of the axle and tires.

with that much clearance there won't be any problem. there is ALWAYS some side-to-side movement as the vehicle goes up and down, the longer the bar, the less the lateral movement. not much but always some with a panhard.

[66-PMD-GMC]

Originally Posted by mavdog32

Dont get me wrong, this isnt a competition truck but I will have it at the strip every once in a while. Its mainly going to be a cruiser with the occasional mustang in the rear view Motor is a turbo 5.3 running around 650-700 on pump gas. I already planned on running the tank behind the axle to get some weight back there. Also going to keep the wood and anything else to add weight back there. I just picture the bags collapsing a bit more than I would like under hard accel and wanted to see if this holds true from people who have them.

BTW this is a 54 chevy

Isn't a 5.3 a 305?
I don't really speak liters.. <--- read old dude
If it is a 305, how in the world are you getting a streetable 675hp average/2.2 hp per sq/inch from a sbc ???