Air Bag basics? Where to read up?

[FirstGen]

I am considering air bags. Is there a good site to read up on the basic's and pro/cons. I'm interested in all aspects like how they work or the lack of in road racing/drag racing/towing/cruising/etc... I would definatly want as compact and light of a kit as possible. I am not concerned with quick pnuematics. If it takes 5 minutes to change ride height etc that is fine if I can get around having a large air tank or any on board air tank at all...

Thanks in advance...

[GreyHoundSteve]

Im sure you are aware of the thousands of posts on this subject in the suspensions forum but if not its a good place to start.

I also have been struggling with the decision to bag my truck or to static drop it. You and i are probably looking at them for the same reasons. It seems like bags are for guys who want to lay frame and get as low as possible which doesnt really interest me however the ability to raise the ride height if i need to is definately a benifiet.

The big hump im having trouble getting over with bags is that there is quiet a bit involved in setting them up and i have NEVER seen anyone use them on the track. I have also heard people complain of tire wear problems and alighment issues as reliablity issues. I also have heard that some of the digital controllers will adjust the pressure in your bags on hard corners which leads me to believe that these are unsafe.

Let me know what you finf out. Im in the north Dallas area and maybe we can go in on a double order and save ourselves some $.

[FirstGen]

I forgot about the suspensions forums I'll do some homework there. Sounds like you are right on track with my needs. I love a low stance however it would be awesome to have the ability to raise the truck for various reasons. I also figured there must be some reason why 18 wheelers use air suspensions for ride quality and the ability to handle heavy loads... I really don't like the ride quality of my truck now with the 4/6 drop springs so this is one possibility and the second being coil overs...

[GreyHoundSteve]

Originally Posted by FirstGen

I forgot about the suspensions forums I'll do some homework there. Sounds like you are right on track with my needs. I love a low stance however it would be awesome to have the ability to raise the truck for various reasons. I also figured there must be some reason why 18 wheelers use air suspensions for ride quality and the ability to handle heavy loads... I really don't like the ride quality of my truck now with the 4/6 drop springs so this is one possibility and the second being coil overs...

Hey First, be sure to stay in touch because it looks like we are neighbors and im only about a month out from doing my suspension so if your looking to do something close to that time frame then we could maybe save some money on a larger buy or if i do decide to go static then i would be interested in buying your springs. I am running 20's up front and 22's in the rear and i want my truck to sit on the wheels just right and it seems like bags are probably the best way to achieve that however my truck will be a daily driver and i dont need any further complications or problems and bags sound like a liability i dont need.

[FirstGen]

Definatly will. I am located right off 75 and 190 in Richardson. A month is about right for me also. If you want these springs we can definatly work something out. They are from Rick's in AZ and are about 4 months old...

[GreyHoundSteve]

Sounds cool. I just bought my wife a new Honda in Richardson from Lute Riley. I live in Lewisville so im not too far from ya. Are the front springs 1.5" drop and the rear 6" drop?

[FirstGen]

It's a 4/6 drop. Truck sat almost level before I put different lower a-arms on for the front disc conversion. Now it sits a little lower in front. Check out the photoshop section and there are some pics of my truck about 10 posts down...

[GreyHoundSteve]

Originally Posted by FirstGen

It's a 4/6 drop. Truck sat almost level before I put different lower a-arms on for the front disc conversion. Now it sits a little lower in front. Check out the photoshop section and there are some pics of my truck about 10 posts down...

WOW! So you did 4"s of spring drop in the front? I was thinking im going to go with spindals and just 1-2" drop springs in front. I'd like to see your truck sometime before you pull them out.

[bagged91]

Airbags 101:

I have a bagged & bodydropped 91 Sierra that was my daily driver for 2 years. It lays frame, bumper & rocker and will drag with the best of them. Look at N2TRUX 77 Cheyenne. It sits right, looks good & is practicle. It is also bagged. You can tailor your airbag suspension to suit your taste/needs/driving style by the way you set them up. I personally have never dealt with the "new" digital controls. I stay with the traditional toggles but to dismiss some of the myths:

Premature tire wear:
IF you properly setup the suspension in the truck, you will not have this issue. You set the truck AT YOUR RIDE HEIGHT then take it to a competent alignment shop and have it aligned(not just a "set the toe & go" shop).

Bags ride too hard/soft:
Again, if you set it up correctly, then you will not have any problems. The more air you put into a bag, the stiffer it becomes. You can tailor it to ride like a Cadillac or handle like a sports car. Swaybars & shocks play an important role in your airbagged suspension just as in a static suspension. If you want to really make your suspension work for you, get a nice set of QA-1 billet adjustable shocks. They are expensive but are sweet...

I don't want it too fast/slow:
How fast your truck/car goes up has to do with the valves/line/portsize you use and the PSI you are running. I have 1/2 single port bags, 1/2 valves with 5/8" stainless hardline and am using an engine driven compressor with a single 7 gal. aluminum airtank. Depending on the PSI, I can raise my truck up nice & slow or hop all four tires 16" off the ground in one hit. I actually bypassed my 175 PSI switch and run mine at pressures upwards of 300 PSI or more at times. Again, your airpressure is all relative, if you aren't running enough PSI, you won't be able to lift your truck up...While 1/4" stuff will work, it is VERY slow and you will most likely want to upgrade later on. I would reccomment going with 3/8 valves, 1/2" line and 3/8 bags.

Finally and most importantly:
Don't try to cheap out on the components in your system. As with most everything else, you get what you pay for. Buy good quality valves, fittings, lines, bags & compressor. A failure in anyone of these items can & will leave you screwed BIGTIME if you are in the middle of B.F.E. I have seen people using anything from rubber airline(like for your home compressor) which cracks & dryrots to plastic tubing and plastic fittings from HomeDepot which are only rated to 100 to 125 PSI. As far as your airmanagement system goes, I would only use top quality parts here. I would go with either Parker or SMC valves and either a Viair 450 or 550 electric compressor or an engine driven compressor(with a good coalescing oil seperator). Keep in mind that the electric compressors pull approx. 30 AMPS ea. Not one to bad mouth a company or thier products and if you are using them(I'm Sorry!)but please stay away from AIM Industries for your air management stuff. I know a lot of people who have had nothing but bad luck with thier products. Sure they have it all and the prices are great but is it worth it if you have to replace it 6 weeks or 6 months down the line? Some problems I have run into with their stuff range from the heads cracking on the compressor to fittings "exploding" to bags & valves leaking. I also would only recommend Firestone or SlamSpecialties bags. Airlift used to have nice bags but I don't like their new gen bags. I personally have had 3 of my customers bags fail due to the rings seperating on the airlift bags(all at under 175 PSI). Again, I have had my Firestones over 300 PSI. I'm not saying that you can get away with it, I fully expect a bag to blow at that high PSI but I also come prepared...

Use only D.O.T. approved airbrake line(and make sure you keep it away from moving parts & exhaust).
Use only D.O.T. approved fittings(all brass prefered)
Use only quality valves (Parker, SMC)
Use only NEW compressor & bags...

Hope this helps....

L8R-Joe

[N2TRUX]

bagged91 is so on track that it hurts....

[FirstGen]

Awesome, thanks for the long post Joe. Do I have to have a air tank or can I use the compressor to fill the bags if I am not concerned with the speed? I just can't imagine where I would stick the tank and I dont want to put it in the bed...

[N2TRUX]

No, you don't have to have a tank. Forum member Scoti has bags on the rear of his truck and uses schrader valves to fill them. If your going to bag both ends I suggest you add a tank under the bed though. There is plenty of room to mount one or two under there.....

[FirstGen]

Nice. Schrader valves? Seems like I know what those are but I can't picture it... help me out.

Two reasons I don't want to have tanks are the bulkyness and the weight. I would love to shave weight not add it whenever possible...

[bagged91]

Schrader valves: Same thing you fill your tires with. You can get them with male pipe thread on one end to fill your bags manually. The only drawback to this is you have to manually fill the bags... These actually aren't a bad idea to incorporate into your system while you are plumbing it (in between the bag & the valve). If you ever burn up a compressor, you can still air your truck up with these.

My aluminum airtank weighs in at about 6 lbs. I went to a heavy truck junkyard and picked up 2 of them for $45 each. With a little cleaning and polishing, they looked like new(and they have a higher burst rating than a steel tank). Like Ken said, you can hide the tank(s) and compressor under the bed for a clean look. They fit well mounted along side the frame between the cab & rear tire like the 73-87 saddle gas tanks...

I plan on baggin' one of my Burbs this summer. I am going to be setting mine up similar to how Ken's truck is set up. The nice thing about the coilspring 67-72's is they are a bolt in for bags.........

[FirstGen]

Ok so if I wanted to put together an ultra simple kit I could do something like this:

Firestone bags front and rear of unknown ratings and heights with 3/8 ports

Small electric pump

Small aluminum tank

4 valves 3/8 port


Is there any reason not to run 3/8 line if I am obviously going to have slow air up times anyway? Not sure I'm understanding the bigger lines than the port size theory?


Better yet, why not mount a small nitrogen tank with a pressure regulator and scrap the pump/tank combo? Seems like it would last for a LONG time before you needed to refill it. Not to mention I would think it would be cheap and if you got a small enough one, not very heavy either...

Thanks again...

[GreyHoundSteve]

Originally Posted by FirstGen

Ok so if I wanted to put together an ultra simple kit I could do something like this:

Firestone bags front and rear of unknown ratings and heights with 3/8 ports

Small electric pump

Small aluminum tank

4 valves 3/8 port


Is there any reason not to run 3/8 line if I am obviously going to have slow air up times anyway? Not sure I'm understanding the bigger lines than the port size theory?


Better yet, why not mount a small nitrogen tank with a pressure regulator and scrap the pump/tank combo? Seems like it would last for a LONG time before you needed to refill it. Not to mention I would think it would be cheap and if you got a small enough one, not very heavy either...

Thanks again...

You need 8 valves. 2 for each bag, one lets air into the bag and the other lets air out. I know it seems like one valve should be able to do that job but it cant. There are some nice diagrams on the suspension forum. When i first got on this site i spent most of my time reading up on airbags and just about every other post of the suspension forum is about them. There are a couple of guys here in DFW who know alot about bags and have been helpful.

[bagged91]

Actually, you only need 4 valves for a basic front/back setup. You tee it off. A small Nitrogen tank will work but the cost of buying the tank & regulator, holddown clamps, & a DOT approved transport guard for the regulator are almost the same if not more as just buying a compressor & tank. The weight of a nitrogen tank(if you use a scuba tank) is about the same as a compressor/aluminum tank, if you get a tank from your local welding gas supplier, it will be A LOT heavier than a compressor/tank. You also have to get the nit. tank certified every few years. They aren't a bad idea as a backup system but they aren't really practicle IMO unless you are running multiple tanks. And, no, they don't last that long....

I have a question... Why are you so concerned about weight????

[bagged91]

You can run 3/8" line with 3/8 valves & bags but I don't like to as it creates a restriction. It breaks down like such:

1/4" DOT line has an ID of 1/8"
3/8" DOT line has an ID of 1/4"
1/2" DOT line has an ID of 3/8"

Using the next size up keeps everything flowing more efficiently. It is almost perfect with 3/8" stuff, not too fast but definitely not slow. If your tank pressure is at around 135-145 psi, it should be nice & comfortable. Approach 175 psi, you will go up fast.

1/4" setups are just too slow. They work but they will annoy you after a while(especially if you need to lift up in a hurry). I am running a 1/4" setup on my daughter's stroller...(see pics below)

You use 1/4" for your airguage.

You are basically looking for a 2600# bag...The measurements are about the same on all of them but like I said, I would stick with either the SlamSpecialties bags or Firestones....

[GreyHoundSteve]

Originally Posted by bagged91

Actually, you only need 4 valves for a basic front/back setup. You tee it off. A small Nitrogen tank will work but the cost of buying the tank & regulator, holddown clamps, & a DOT approved transport guard for the regulator are almost the same if not more as just buying a compressor & tank. The weight of a nitrogen tank(if you use a scuba tank) is about the same as a compressor/aluminum tank, if you get a tank from your local welding gas supplier, it will be A LOT heavier than a compressor/tank. You also have to get the nit. tank certified every few years. They aren't a bad idea as a backup system but they aren't really practicle IMO unless you are running multiple tanks. And, no, they don't last that long....

I have a question... Why are you so concerned about weight????

If you only run 4 valves then wont you have side to side movement of air between the bags?

Thats the way i understand it. I think firstgen is more insterested in perfomrance then just dropping his truck down low in which case a 4 valve system is not the way to go. (from what i understand)

[bagged91]

Yes you will but I haven't noticed any signifigant effects from it. If you aren't running a sway bar, I could see this being a problem but the swaybar counteracts most if not all of the side to side air transfer.

Now, go back and read his post again and read mine. HE said an ULTRA SIMPLE KIT. HE mentioned 4 valves. YOU said it won't work. I say it does, and that is from EXPERIENCE. And btw, you can have one valve per bag and have F/B/S/S. You use a 3 way valve(inlet/fill/exhaust).

[GreyHoundSteve]

Originally Posted by FirstGen

I forgot about the suspensions forums I'll do some homework there. Sounds like you are right on track with my needs. I love a low stance however it would be awesome to have the ability to raise the truck for various reasons. I also figured there must be some reason why 18 wheelers use air suspensions for ride quality and the ability to handle heavy loads... I really don't like the ride quality of my truck now with the 4/6 drop springs so this is one possibility and the second being coil overs...

Well bagged91 i went back and reread his and your posts and from HIS WORDS "sounds like you are right on track with my needs" i would have to say that a cheapo airbag set up isnt what he is looking for. When he says "simple" i think he means he doesnt plan to hop the truck or lay frame i dont think he was talking about a cheap set up that will give him problems and poor performance. I might be way off base here but ive seen enough of firstgens posts to know that he is pushing some serous hp and also has a sport bike so that leads me to believe that is not the kind of guy who wants all show and no go and i can relate to that since i also prefer function over appearance. Im not trying to challenge your knowledge on air bags because i am SURE you know a whole lot more about them but i have also been here long enough to notice that guys who run bags make it sound so easy and cheap when in fact it is anything but. Im just trying to help a fellow board member make an educated decision and ive heard "buy the bags and run schrader valves and your good to go" too many times to rest easy when i know thats not the case. There is more involved than that and if the guy went through enough trouble to drop in an ls1 then im sure he doesnt want to scimp on the hook up he will need for that set up.

Im simply saying to him .... dont rush into this decision because youll find out that theres alot more to an airbag set up than just bags and a filler valve and the more you learn the more $ you realize you have to spend to do it right.

[bagged91]

Just because I have a bagged truck that lays the frame doesn't mean that my truck isn't functional or practicle. Remember, different strokes for different folks... Bags aren't for everyone. It seems to me like you have a preset disposition on airbags and you are letting that influnce your comments on this thread. I don't see where I have said anything at all that isn't trying to help FirstGen out. I dispelled some of the myths that you had brought up and gave some pointers to look out for. I am speaking from real world experience here, not from something I read on a screen. Ken(N2TRUX) also backed me up 100% on my first post.

You are right, it isn't as simple as some make it seem but it isn't as hard as you are making it seem either. It's not rocket science. You are replacing a steel spring with an air spring. There are other things to consider but for the most part it is that simple. There is no need to overcomplicate it as it is complicated enough. Like I said before, it is all in how you set it up as to how it will perform. If you don't know how to set it up, then take it to a qualified shop to perform that part of the job. That's what we're here for...

I'lle give you one more piece of free advise, if you have doubt's about whether you will like an airsuspension in a truck, find someone local or at a show with a vehicle set up how you like it and ask them to take you for a ride. I know I have probably given 25-30 different people rides in my truck. Most are surprised at how nice it rides/handles.

If you would like to discuss this further, please feel free to PM me but I don't want to discuss this anymore on the thread... It's getting WAY OFF TOPIC...

[FirstGen]

Well either case thanks for both of your posts. I have only done a very limited amount of research on airbag setups and I appreciate your input.

I am concerned about weight because I have a somewhat large group of friends and we are all talking **** all the time and going to the track. I know where to pick my battles and this truck is by no means a race car, however I can still destroy 90% of these guys that think they are bad asses in their "mustang with a blower". I would like to keep it that way. Weight plays a huge role in a vehicles advantages or disadvantages from this perspective.

Basically to sum it up, my truck is totally for fun and if I add alot of weight to it, that will take away part of my "fun".

I guess I was thinking more about these carbon fiber tanks we use to use in paintball. They are about half the size of scuba tank. It was really just a late night thought. Looking at the costs of a small ViAir compressor it just wouldn't be worth it. I'm sure I could find some sort of small tank to accompany it also.

Would something like this get the job done effectivly again remembering that taking 60 seconds to air up a few inches is fine:
http://cgi.ebay.com/ebaymotors/ws/eB...category=50073

I definatly do not want a lousy kit. The only place I am willing to sacrifice is the speed of the lift of the bag. The most important is the ride quality. Ultimatly, I am debating air bags VS coil overs. Sounds like both will run me around $800+...

I don't care to have the ability to raise or lower the truck left to right. I can most certaintly do some more reading before you answer more questions if you are tired of posting answers that I'm sure have been asked before. I guess the way I was thinking was to run bags on all the corners, run a line across on the front to the left and right bag and then to T into it with your two valves. Same on the rear. Does this sacrifice something besides the ability to move side to side?

I guess the last question would be what is wrong with with saving your money and buying good bags and installing them with schrader valves temporarily untill you can piece together the rest of the parts in your kit?

I understand what you are saying about the line ID, makes sense.

Thanks again guys!!!

[GreyHoundSteve]

My bad bagged 91, i wasnt trying to make it seem like bags were "rocket science" but it isnt as easy as replacing a spring either and bagged guys like to make it sound like it is because its second nature to them. As for the "myths" .... i dont honestly know what your talking about? Its no myth that a bagged set up is going to have alighnment issues because like you said yourself .... most people arent familiar with alighning these types of set ups and therefore they will be alighned improperly most of the time and if your running 20's like some of us then it can be a costly error not to consider the very real possability that it will happen. Youve also said yourself that bags installed wrong can and will leave your stranded .... thats no myth either.

The way i look at it is that bags vs static drop is kinda like shaved vs unshaved. I love the looks of a bagged truck with the doors, cowl and drip guard shaved but if that truck has to be your daily driver then expect water in the cab from not having a drip rail, expect your ac controls to not work properly with a shaved cowl and expect that at some point your doors wont pop open and your going to have to find another way into your truck. Same goes for bags, they look cool and the more your spend on them the more reliable they can be but pretending like they are as problem free as a set of springs is just not right. Dont get me wrong .... on a show truck or a sunny driver i love bags but if its your only vehicle and you cant miss work or dont want to be stuck on the side of the highway with your 3 year old with you then there are other considerations to take into account as well.

[bagged91]

Gotcha on the wieght thing. The air system really doesn't add that much weight. Maybe an additional 30lbs when you figure the weight you will be loosing with the coils. The compressor you showed on Ebay would work. I stated a 450 or 550 because they are rated at 100% duty cycle, meaning they can run basically all day w/o burning up, whereas that one on Ebay will fry if you try to do that. A new 450 can be had for around $175 - $200 or so.

The one advantage that having F/B/S/S has over just having F/B is that you can infinitely adjust your truck. Say you are leaning a little to one side, tap it up/down. You want a little more bite on the rear, adjust the R & L bags accordingly. They do have their advantages. For just a simple trouble free system, a F/B system will work fine, as GHS mentioned, there is a small amount of air to air transfer from left to right on cornering & such but your sway bar cancels that out. I recently did a 2001 Silverado with F/B with a cantilevered 4 link I fab'd myself. It rides beautiful and handles like OEM.

FirstGen, are you a capable fabricator or do you know one that is willing to help? You can shave some of the cost off your bill by making the bag plates & cups yourself. You may also want to make an adjustable panhard bar if you don't have one already. Figuring $800 is cutting it a little thin for all the components. I usually spend close to $1300 to $1500 for everything. Those stupid little fittings add up...

Using the shrader valve will work but I personally wouldn't run on the street with it like that. I would rather keep what I have for now and just do it all in one shot and get it over with.