|04-26-2006 04:11 PM|
|motorcitydak||what is an exected pressure i can get out of an oba setup? if i run 5 inch cylinders, i should only need about 80psi or so, but if I can get 120psi in there, they would lift 2350lbs each, meaning I could lift a vehicle straight up and out of a hole or something. Basically, I would have an extra 2000lbs or so of lifting force on the front end if needed. The axles and mounts would then worry me, but it is possible.|
|04-26-2006 01:21 PM|
I remember talking to you and reading that thread for days a while ago. That is obviously where I got the ideas from. My cylinders would be as straight as possible and like I said, prob 5 inch bore.
You are using hudraulic rams in there if I remember rite. Do you have a problem with the seals failing and then losing suspending abilities?I figured if you kept air tool oil in there, you would be fine, but I was thinkin pneumatic cylinders since they are made to be run on air anyway.
|04-26-2006 12:51 PM|
Its not that heavy, 560Lbs per rear corner of sprung weight rear, I do 3in rams and it requires about 80PSI to lift it.
D= piston diameter
At 80 PSI Im about 560Lbs per corner.
The weight also needs to take into account your mounting angle at 45 degree the ram needs to hold up alot more weight then vertical mounting.
Use geometry to figure the force if angled.
We have a jazillion page thread on this:
|04-26-2006 12:17 PM|
|motorcitydak||ok, sorry. my physics isnt so good, but i just figured out the area of a 4 inch bore cylinder is 12.56 inches. Maybe a 5 inch would be good for me, 19.625 inches and would have 1766# of force at only 90psi. With 2355 per corner and 120psi!|
|04-26-2006 11:53 AM|
|04-26-2006 11:15 AM|
F = P x A.
119 psi in a 4" bore will support 1500 lbs.
159 psi in a 3" bore will support 1500 lbs.
|04-26-2006 10:50 AM|
|04-26-2006 05:20 AM|
The air shocks would be nice if they were not basically for rock crawlin. 1000lbs per corner is all they can take.
So how bout some pics of your setup
|04-26-2006 01:35 AM|
i guess I just vision them as being really limited..
I mean sure you can adjust them but...
say you got a 5k rig (pretty common) you put enough air in them to get the rig to sit where you want it with the right amount of uptravel..now you want to go fast...
so that volume of air don't fit into the equation of smashing it into the whoops and having it not be way to:
A soft and bottom out
B harden up to fast..I.E. get TO progressive..
SO you can still adjust it IF those cannot be corrected..but how often..do you have to adjust it for every terrain type?
I would like to be proven wrong and enlightened..this is what this site is for..please show us..
I think if we could see a setup that when tilted at say...90 % load OFF of one end..and not totally unload..be able to crawl without being stiff..and still be able to medium pace trail run without bottoming out all over
AND being able to hit like say even 1 ft whoops at like 15-20 mph without bottoming..all on one setting then yes I think I could deal with having to adjust them to more extreme adversive situations..
but for what I wheel..all those things need to work equally as well in those peramiters..
I am not hitting 7 foot whoops at 100 mph..nor am I unloading 99% of my weight off of each corner all day long (well) but a happy meduim?
do they arok for that kinda stuff?
|04-25-2006 11:24 PM|
we have run this setup on my friends buggy. it is a heavy ass pig. the air rams work ok at best. unload like mad. they don't work anything like an airshock. airshocks work off of basic volume displacement. yes the co2 will quickly turn back into liquid. i am surprised you are even getting 1k psi out of them co2 is a really bad idea. at least normal compressed atmospheric air is 78% nitrogen and its cheap. with the 3" ram you will be able to suspend your rig with around 120# of air. you can run that off of your on board air comp.
we just cut down some poly bushings and used those in the eye of the ram. even kept the 1" pins.
air shocks are only $200 each. just pm a few of the vendors. albeit you may be too heavy for simple 2" body shocks.
|04-25-2006 11:23 PM|
|04-25-2006 11:05 PM|
|04-25-2006 06:21 PM|
You dont actually need OBA, you can just use your air compressor at home or something else i have been pondering...Lift up the front(or where ever the cylinders are at) to a desired height and open the valves up to equalize the pressure, then colse em up and put the rig back down and see where it rides. I know its a hilly-billy trial and error way to do it, but its still possible.
Stinkbug-But you dont have to mess with how much oil is in the shocks, gettin nitrogen for it and all the equipment you need for that and there is not weight limit like the air shocks(1000 per corner). the cylinders can supports 10,000 pounds and up. I already have some 12 inch travel procomp MX6-Rs and am building this to fit em and a cylinder. Plus, its more fun to make your own system than just buy somethin and put it on.
Schmozilla-you can adjust your rate to what ever you want by how much pressure you are runnin in the cylinders.
Moab Austin-of course you can use regular shocks, the cylinder will act just like a regular coil spring, but much better. With the unloading, you can always pressurize the bottom more so it wont drop out as far and as long as its closed, the cylinder wont bottom out till you want it to.
Honestly, I see this setup as one of the best suspensions I can imagine. You can conrtol EVERY single aspect of it from the cab with a few buttons, try doin that with a coil over or an air shock. Now someone will say that you can get a c/o's with the airbags around em and remotely adjustable shocks, but they are very expensive compared to my setup.
|04-25-2006 05:00 PM|
|keebler303||the point is its instantly infinitely adjustable|
|04-25-2006 01:13 PM|
Ok now add the cost of a good set of shocks, roughly another $100 per corner. Now you're just shy of the cost of a set of real air shocks, and you haven't even added up the cost of the OBA, solenoids, or plumbing.
|04-24-2006 09:35 PM|
|Schmozilla||what kinda spring rates are you gettin... seems like it would be pretty damn stiff...|
|04-24-2006 08:31 PM|
oh ok I thought you meant to replace all of it..
I retract my "sucks" attitude and just pose it in a question now..
how does it work with bumps? can you get shocks off the shelf to fit in the dampner department?
what about unloading..I.E. when you are climbing steep and the front gets "light"?
I am sure you can just dump some pressure, or even make a fancy valve that could do it automatically...but is unloading and issue?
|04-24-2006 07:57 PM|
Its not a cantilevel either, just a different way to support a truck and have a very easily adjustable suspension, both in ride height and rate.
|04-24-2006 07:37 PM|
yeah but they don't work as good eighter..
what you guys are talking about is just a straight air ram in place of a shock..?right?
OR are you talking making a cantilever setup that is used to adjust your whole coil/shock mount to raise vehicle higher?
|04-24-2006 07:29 PM|
|motorcitydak||o, and they dont cost near the amount of air shocks or c/o's. Maybe 100 bucks a clyinder.|
|04-24-2006 07:26 PM|
|04-24-2006 07:09 PM|
|04-24-2006 06:28 PM|
|Schmozilla||Id like to know more about this setup If you dont mind explaining more in dept of how you set it all up...|
|04-24-2006 05:55 PM|
|motorcitydak||can you send me some pics of your setup. I was just plannin on an OBA setup to power em, but I cannot do the math to see what they would lift w that pressure. BTW, that was total weight, not only sprung. Its for a 96 dakota w a v6 5 speed, not a very heavy truck. thanks dude|
|04-24-2006 05:48 PM|
|IHREDRIDER||Your plans are not feasable. Assuming 3000# on the front you have to plan to move atleast 4000# per cylinder. And a 4 in bore has ~12.5 ci. Therefore @ 90 psi you will be able to lift ~1125#. That is not enough. Better get somemore pressure. I use CO2, ~1000psi into 2.5 in cylinders. This allows me to adjust ride height at any angle on a 4200# rig.|
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