Sounds like your well over the divorce thing, never pretty from what i have seen.
Pleased to say my other half and i have been together for going on 40 years.
So, my front suspension is coming along nicely and even tho it wont be super low, it still looks pretty good to me and the bags will allow it to sit almost on the ground when aired out. I like the nice compliant ride that bags give to. However i do believe the correct shocks are critical to help achieve that compliant ride.
Airbags (airsprings really) dont have the same qualities/behaviour as say leaf or coil springs and so i intend to do some research on that topic. Any suggestions?
Wont be too long i hope before i can remove the body and look into the rear suspension setup, should be interesting to see how that goes.......
Thanks so much for the positive feedback guys, i hope it provides a little inspiration and light entertainment. LOL cheers John
I'm pretty knowledgeable about shocks, but using them with bags is far outside my sphere. Bags definitely have a different response characteristics than steel springs. The people from Air Ride lurk here at times, they would be the people to ask about how to choose shocks.
In my experience there isn't really anyone making a shock specifically for vehicles running airbags. There are a couple of places that offer shocks for lowered trucks but I can't personally vouch for them. I'm personally using bilstein 5100 and like them do far but I'm still building my truck so I have only been able to see how quickly they take the bounce out of the ride when I manually push on the truck.
I didn't get a chance to read the whole thread so perhaps you already mentioned it but what brand bags are you running. I only ask as some are stiffer than others.
HI, i am using Firestone Riderite airsprings, part no 14793071.
So if you dont mind me asking a few dumb questions........
On a vehicle such as mine, 56 panel running full independent suspension and a full alloy construction engine what would be an average pressure for the front airsprings at normal ride hieght?
Now i know thats a REALLY loaded question with MANY variables but.........
What i am trying to figure out is how does one work out the mounting for the bags to get the best ride performance at or close to normal ride height?
As you mentioned, that is a very loaded question. The pressure is going to vary depending on everything from bag construction, location of bag, to even weather conditions. With that being said, I would take a rough guess that the front psi would be in the neighborhood of 70 psi assuming your ride height is about half travel for the air bag. It might be a little lower psi than that due to your limited weight.
For setting up the bag location and where to place along a bellcrank, I come from a slightly different background of where being as low as possible is the first priority. Some of our techniques though would apply to your application. General rule of thumb is that you want the bag to be at half travel at your desired ride height. Typical bags have a collapsed height of 3” and an expanded height of 9-10”, so for mock up I would suggest that you leave a space of roughly 6” for the bag. At the end of the day though if you are also concerned about going as low as possible you can approach it from a different angle.
If you are going with a bell crank design, I would start by putting the frame at the lowest point it can go/where you want it. Make sure that you are not overly binding ball joints or hitting the control arms on the frame. There is a good chance that the sway bar might hold you up before anything else does, but this varies quite a bit between IFS designs. Also, make sure the rear of the frame is where you want it at well, you don’t want to setup the front end with a serious rake especially when using a bellcrank design that does not appreciate designed twisting.
From here I would look at where the bag will physically fit, more than likely there is going to be a limited area where this is even possible. I would ensure that you leave at least a ½” preferably more all the way around the bag. The softer bags such as the Firestones will have a tendency to balloon out during the cycle so you may want to shoot for more clearance, typical size is a max diameter of 7.5” for a 2600lb bag. I would then cut a piece of 6” tube or even a piece of 2x3 tubing down to 3” tall and use this as a collapsed mock up height. This should give you a good starting point to know where all of your pivots will have to go for your bell crank to actually function and clear the arms/frame/engine.
A final note to consider is that ideally the top plate and bottom plate of the bag should be parallel at your ride height. Using a bell crank design you will clearly have quite a bit of angle in the bag from full lift to laid out. There is a designed limit on the bags on what angle they can be off by but at the moment I’m having trouble tracking down that info again. It’s quite a large range though, you shouldn’t have any issue with going over the limits.
I apologize for the lengthy post, it’s just not a simple subject to briefly cover. Also, I sent a link of this thread to our main engineer on our performance side of AirLift. If he has any additional input I will be sure to forward it on.* Let me know if you would like for me to explain anything in more detail.
Something else I meant to mention is your lift height. Not sure how much wheel will be tucked when aired out, but you will need to consider this obviously when setting up the bags as well. You may want to throw a wheel and tire on with the same OD as what you intend to run, throw a fender on as well and cycle through the steering.
Your designed ride height doesn't necessarily have to allow for full turns but hopefully so. At the very least you need to ensure that you can get enough lift to get full turn radius.
Air Lift, sorry to have called you "air ride" earlier.
You bring up a good point, airbags are complex, and can and do fail occasionally, if when fully deflated your tires hit the undersides of the fenders, cannot be steered, or parts hit the ground (like the oil pan ) and you have a sudden failure while driving, you could be in a world of serious trouble!
Actually sitting on the ground may impress some at a lawn ornament show, but won't impress anyone while doing uncontrollable 70 MPH donuts down the interstate with a ripped off steering or oil pan. If you use bags and drive your vehicle, err on the side of safety, the life you save could be mine!
Wow, thanks so much Airlift for all that valuable information, i can assure you its much appreciated.
Yes i am approaching this not so much from low as first priority, i can still have that when parked anyway. Here in Australia we have minimum ride height laws with the vehicle running plus i live in a rural area with typical rural roads.
My truck (by Law) will be fitted with bump stops which prevent anything dragging below the scrubline in the event of a failure.
What i was concerned about was ending up with an overly harsh or too soft a ride at normal driving height, you have certainly helped with that.
I have started on the crossmember to pickup the rear lower a arm points, made a template and then cut these plates out with the Plasma. A little cleanup work and Hey Presto, plates with slots for the camber adjustments. John