looking at doing a 4 link air ride from airbagit. anyone have any experience with full air ride suspensions?
My front air ride suspension is working well. And I'm working on an air ride cab suspension.i am working from 5pm to 3 am (nights) and i can only use the computer during certain times of my shift. I am very interested in doing the front as well as the rear.
Height control valves. Easy to set up.The system i was looking at for self height adjustment would be similar to the big rigs. just a valve with a mechanical feedback rod attatched to the axle.
I made mine. I pressed RB155 rubber bushings into 2.5" 0.25" wall DOM tubing. I've been driving it for a year. I inspected the bushings this weekend and they are showing a small amount of deformation. I'm not sure if I should have used a harder bushing or not. I got my bushings at a HD truck shop. I buy most everything I use on my truck from HD truck shops.I will try to find the write up and do some research. Where do you guys buy the parts from? link ends mostly, i guess everything else is manufactured
11R-089 if you are following my lead. You need a ride height of about 12 inches for a soft spring rate.looks like he does wonderfull work but i am not that rich and i would like the pride in doing my own if possible. Pretty well decided 2" dom tube with 2.5" dom on the ends with the pressed in leaf spring bushings. the goodyear bags 1R10-089 i believe.
My 5er is about 13K.Just need to work out lenghts and such. My diesel weighs about 8500 lbs and i my fifth wheel camper is 10,000 lbs so i just want to be sure i do it right.
Stock height is way harder than lifted. When lifted there is lots of room for everything between the axle and the frame. Stock height means you really have to watch things, especially if you use a tall bag.Want to do stock height with 33" tires. any more reading and such would be great.
Thankx a bunch. need to actually be with my truck and do some cyphering. I work construction and will be home in 2 weeks. want to buy some parts when home and try some measurements, but need to know what i am looking at when i get home.Where to start, where to start...
Here is what governed me.
- I wanted the bars about 12" apart on the diff. The further they are apart, the lower the force in them. My bars see about 5,000 pounds of push/pull worst case, which is 6,000 pounds on the axle with tires skidding on really good pavement.
- I wanted to use a long travel bag for a low spring rate and a good ride. That means a ride height of 10 inches or more. That means the bag had to ride behind the axle. I agree
- I wanted to retain nearly stock ride height. I agree That means the axle must be able to touch the bump stop on the frame fully compressed, which means the top link on the axle must be within a few inches of the top of the axle or it will hit the underside of the box. (About 4" above center of the axle) 4x4 may allow more room above i agree
- Given the top axle mount must be close to the axle and the lower one must be 12" below it, its going to be about 8" below the center of the axle.
- I wanted the bars to be as long as possible to avoid as much bump steer as possible and to minimize anti squat. This i didn't know but agree with
- I wanted the bars to be parallel This i am not too sure about
- Given these two things, the furthest forward I could mount them was behind the rear cab mount. I went about 6" behind it.
- I put the top frame mount pretty much as high as possible and the lower frame mount 12" below it. if i make bars unequal in lenght can i then shorten the distance and still keep strenght?
Once I got all this figured out, I ran the 4 link calculator and the numbers came out pretty good. I think I had 20% antisquat. In practice, the back end of the truck does not move up or down at all when braking or accelerating. To me this is paramount. This is also very good
My bars are 31" long but should be an inch or two longer to better center the wheel in the wheel well. I under estimated how high I would run the suspension compared to where it ran with the sacked out leaf springs.
This i will keep an eye on
Hope this helps.
I don't think its necessary to make the links adjustable at all.Although more expensive, it would be a good idea to make both the upper and lower arms adjustable. This will allow you to help center the axle within the wheel well aswell as alignment.
Maybe for a rock buggy. On a highway truck the torque rod is as high as possible on the diff so that it has the least amount of stress. If you are going to be hauling, I suggest spacing them apart as much as possible.Rule of thumb on spacing is 1" of spacing between the bars per 4" of tire.
The Superduty driveshafts have slip joints. When the rear diff is riding on leaf springs it DOES NOT follow the arc of the driveshaft from the carrier bearing. Its more important to get the anti squat and roll center stuff correct than it is to worry about the slip joint movement.Making the links the length and angle of the driveshaft will allow everything to rotate on the same radius and prevent your driveshaft from coming apart/smashing into itself.
The 11R-089 is an 11 inch bag. The 5370 is 9 inches, but doesn't really have enough capacity. You need more than an inch between the bag and the tire and more than 1/4" between the bag and the frame.i just did some measuring on a truck of similar specs as mine. i think i will have about 10 inches between my tire and frame. Does this mean that the airbag will actually come up the outside of the frame? I am going to try to keep the bag about 1 inch from the tire and 1/4 inch from the frame and close to the backside of the axle.
For a good ride, you need an air column of 12 inches or more. For the 11R089, that means a ride height of 12"+.Yes the driveshaft angle is an issue and i will try to keep it as close to stock angles as possible. what lenght of travel, in the bags, do you need while you drive the truck.
The 11R-089 has a minimum height of 4". The axle will touch the frame before it bottoms.the truck will be set up to sit at about stock height, but when the suspention moves, during regular driving, what kind of travel can i expect in the bags. I have front and rear axle antisway bars. thankx...
Probably.so at least the edge of the bag under the frame,and appropriate support.
Something like that. You can't go by the static bag diameter because the bags get larger with increased pressure, like when you hit a bump.how far away from the tire should i run the bag? Is 2 inches or 3 inches
Height or diameter ? Its all in the bag data sheet.How far will the bag actually extend if i wanted it to?
Nope.the bag will only reach a certain pressure (this is a combination of dia of bag and weight of truck) then the bag will remain at that pressure and continue to raise truck untill it reaches end of stroke, CORRECT?
Yep.but when additional weight is added to truck ride height will drop slightly and pressure will raise to compensate. Is this correct thinking?
Not really. I say that to get a decent spring rate for a good ride frequency (1.5 Hz or less) you need a 12 inch column of air. In conjunction with a bag that doesn't have too much area change.So when you say 12" of air column this is to absorb bumps and stuff while travelling and not allowing any bottoming out of suspension.
I went through everything you are going through and more. It takes a lot to design a good air suspension. Its way easier to ask questions now than to ask them after everything is welded together.New to this stuff and trying to get it figured out. Just typing it out and thinking i think it makes sense.