when i got my mag this month (i think its peterson 4wheel, i get like 4 a month) they have a little book with it and there is a little section with roll cages and they say you can use it as an air tank. obviosly you have to put fittings and seal it... it sound like a good idea but has anyone ever seen this??

yup. drill a hole at each node where 2 (or more) tubes intersect. that way everytube is connected. pressure test for leaks. plumb the compressor to it, put some fittings front and rear, in fairly well protected spots.

works for bumpers too.

and no, it wont explode.

The number of joints in a roll cage make it tough to seal for air, but a lot of people try it. It's also pretty common to use the bumpers for air tanks.

Bumpers are not too big a problem, but a roll cage would be a welder's nightmare to try and seal it 100% for it to work, plus you gotta make sure you bung the joints so the entire cage acts as if it were a tank. Im sure it can be done, but what a PITA.

Andrew

hell, some buggies use parts of their cage/frame as plumbing for their cooling system.

Do you think I could use my cage as an aux fuel tank? LOL and I could just wire my speaker wires through there as well and save lots of space!

as an air tank sounds like a slick idea, but anything else like plumbing would be dumb, how would you repair lines run through the cage?

Seems like if it was pressurized to 120 psi, the whole thing would be less safe in a rollover. A small rupture would be bad, but just kinking the tube might make the air pressure dangerously high... :shrug

Or maybe you can just be a good welder, I wouldn't know what thats like...

a buddy of mine back at ft. bragg has his pre-runner bumper as a back-up air tank, i think it's a great idea.

as for a full-cage tank, i agree it woud be a huge PITA, but it has been done before.

would you really have to air it to 120 psi though? there has to be some equation to use to see exactly how much pressure you would need to fill 4 tires, taking into play the tire size, psi in the tire and desired psi, temperature, etc. I dunno cause i slept half my semester in calculus.

hell, some buggies use parts of their cage/frame as plumbing for their cooling system.


isnt that cool? shaffers uses his ram mount as a "reservior" for his diff breather based on the fact that it wont really need that much air to breath

A small rupture would be bad, but just kinking the tube might make the air pressure dangerously high... :shrug


nah, what would cause the increased pressure? it would be a HUGE pita to seal it anyways, unless you just wanted to do a few sections, which wouldnt hold much air anyways

Do you think I could use my cage as an aux fuel tank? LOL and I could just wire my speaker wires through there as well and save lots of space!

as an air tank sounds like a slick idea, but anything else like plumbing would be dumb, how would you repair lines run through the cage?


They don't run lines through the cage, they use the tubing itself. A lot of buggies use the main frame tubing to run coolant to a rear mounted radiator.

As for fuel, NASCAR and Indy cars used to cheat by storing extra fuel in the roll cage, it's nothing new.

I was just thinking that if you have a certain volume of air at a certain pressure, then you kink the tube... ahhh hard to explain.

Think of it like taking a new bag of chips and squeezing it suddenly.

I was just thinking that if you have a certain volume of air at a certain pressure, then you kink the tube... ahhh hard to explain.

Think of it like taking a new bag of chips and squeezing it suddenly.

its only 120 or 150 psi. if you punctured it, all the air would just rush out, like when you hit the release on an compressor tank. it wouldnt explode, sending shrapnel all over the trail.

a kink in the tubing wouldnt drastically change the entire volume to make much of a difference. if you had a regulator on it anyway, it would bleed it off if the pressure was too great.

Cool, it's safe then. I'm still not a good enough welder to make it happen.

Squatty is right on.

120 psi is peanuts in steel.

For a comparison, we put 2,216 PSI in lightweight steel Fire Department breathing apparatus tanks. That will explode nicely if given the chance, but failures are almost non-existant, even with all the abuse of firefighting.

New tanks hold 4500 PSI with a little reinforcing.

so if you were to make one of these airtank bumpers(like the 4in diameter one i'm building) how hard would it be to make it hold air if you were using a stick welder? the tube is 1/2 inch thick and the ends and a notch in the middle are the only places where it's cut.
and anyone got a link to a site with that calculator? to figure psi in tank given tank size and tire size and before and after pressures?

Squatty is right on.

120 psi is peanuts in steel.

For a comparison, we put 2,216 PSI in lightweight steel Fire Department breathing apparatus tanks. That will explode nicely if given the chance, but failures are almost non-existant, even with all the abuse of firefighting.

New tanks hold 4500 PSI with a little reinforcing.

the new ones arent steel anymor either, just to be totally accurate. Typically they are carbon fiber or kevlar wrapped aluminum shells, and have a useful life of 9 to 15 years max IIRC, per the manufacturor

Just out of curiosity, wouldn't you collect a lot of water inside of the tubes by compressing air in them with no way to remove it? Kind of like the inside of a compressor tank after each use?

I suppose that we can put Nitrogen and any other gas in there as well?

Has anyone exceeded 150 psi?

WOW.....we go back to high school and college math, cubic feet and pressure.

How many tires can you fill?

if you fill your roll cage with helium it makes your truck lighter

They don't run lines through the cage, they use the tubing itself. A lot of buggies use the main frame tubing to run coolant to a rear mounted radiator.

As for fuel, NASCAR and Indy cars used to cheat by storing extra fuel in the roll cage, it's nothing new.

You'd think as a longtime nascar fan I'd have known that, well I guess if you don't learn something you just wasted the day. As far as coolant in the tubing, one to the cooler the other for the return? I haven't ever looked at the sand cars round here, but I hadn't noticed anything like that. I can think of more than a few potential problems with a system like that, I'd prolly stick with hoses. But then again I always have been known to lean towards old school thinking.

so if you were to make one of these airtank bumpers(like the 4in diameter one i'm building) how hard would it be to make it hold air if you were using a stick welder? the tube is 1/2 inch thick and the ends and a notch in the middle are the only places where it's cut.
and anyone got a link to a site with that calculator? to figure psi in tank given tank size and tire size and before and after pressures?

The only formula I know of off the bat is:

(Pressure x volume)/Temperature = (Pressure x volume)/Temperature

Your tire temp and bumper will probably be close (if you are stopped for a flat or whatever) so you could probably ignore those. I think if you know the exact volume of air your tire holds at the pressure you want it, and you know the exact volume of your bumper, you can plug in the numbers you have and get the air pressure you need to maintain in your bumper to be able to fill all your tires to the desired pressure. OR, you could just carry a full scuba tank with the right adapter/fitting...

Later,
Chris

if you fill your roll cage with helium it makes your truck lighter
:histerica

OOO! OOOOO! What about filling it with beer!? On tap, oh yeah. :beer (Tap in the back, of course... never drink and drive!)

Heck, fill with liquid CO2 and youll have enough air for the rest of the trucks life. Then you can bet your drunk buddies on the old touch your tounge to the cold metal thing.

anyone know the volume of a 33x12.50 tire? very ruff estimate at 6000 inches cubed.

tire presure*tire volume + tank presure*tank volume = (tire volume + tank volume)*Final presure

10*6000+x*940=(6000+940)*35

tank presure to fill one 33 inch tire from 10 to 35 psi
= 195 psi
to go from 20 to 35 psi for one 30 inch tire
= 120 psi

in my case. and assuming temp is the same before and after.

i vote for making my tube a highlift storage facility