L33T35T 4Runner

ok george, you have my attention

we need details man, DETAILS

link to your regulator purchased online?

SkyRat

Here is where I got the regulator .

They are in So Cal and it was inexpensive and works very well!!

More to come in a few days....

4Crawler

iTrader: (3)

You can answer that question yourself with the information on my page.

Simple matter of plugging in the tire volumes and pressure and the tank volume and pressure and work out the answer. The example I use on the page shows a 20 gallon tank at 150 psi would take 4-33x12.50 tires from 10-30 psi.

jacksonpt

Thanks for the math... good to know my highschool algebra is still working. As near as I could figure, the 10g 135psi tank won't be enough for my needs. But... it might work very well if I paired it up with 2 caddy compressors. The tank would be enough to airup a flat on the trail to a typical trail pressure (i.e. 20psi). Plus, with the compressors, I'd be able to air up after the ride without any problems.

I guess the question becomes is all this really worth it? Or should I just go with a CO2 system or a good on-board air style compressor?

4Crawler

iTrader: (3)

Its all a matter of time and money (how much you want to spend on the system and how long you want to wait to fill the tires), plus room for the setup, whether its a tank or compressor or both. I went with an under-hood, 12V compressor (and may be adding a 2nd) and some under-truck mounted tanks, as I didn't want to loose the interior space. Also, wanted the air to always be there, not something I would have to remember to pack or fill up before a trip (I'm bad with things like that).

Mad Chemist

Jackson-

I've gone the compressor route, and got tired of waiting 45 minutes before my tires were aired back up. Its a real pain at night, especially if people are waiting to use your compressor after you. With my CO2 tank, its out of site in my cargo box, but man is it nice to be able to air up about 2-3 vehicles in the time it would take to get just a couple tires done witht the compressor. My 10# CO2 tank I bought off ebay for ~60 bucks, and actually got the springy polyurethane hose from Sears. The reg I borrowed from work, and hope to get a high outlett press. reg. soon. Welding supply stores will have an exchange program for steel tanks, I'm not too sure about the aluminum tanks. If I did it again, I might have gotten an aluminum to get something a little lighter. However, I'm not sure if most welding places will exchange aluminum- I just dont' know. The disadavantages are the space- I have a custom cargo box in the back of 4runner, so I just leave it back there all the time. However, if space was limited, you'd be lugging it in and out for runs, while a compressor is small enough you could just stash in the back seat. I actually carry both now- my old colman compressor, and the CO2 tank. THe compressor is a "just in case" measure, since its hard to gauge when the CO2 will run out. The reg shows a constant pressure until all the liq. CO2 is boiled off, so when you do see a decrease in pressure on the reg, you're almost out, and this will happen right on the trail. Its hard to remember exactly how many tires you filled up, so you end up replacing tanks a little more often to play it safe. Here in Seattle, its about 11 bucks for a new tank.

Hope this helps!

jacksonpt

What compressor did you go with? Is it reasonably efficient? I like the idea of having the tank/compressor combo - tanks mean air is ready on demand, compressor means unlimited air supply. I don't need a compressor that is ultra fast, but something that is about the same speed as typical compressors at gas stations would be nice. Is it reasonable to hope a 12v uner-hood compressor could be as "fast" as a gas station compressor?

The caddy compressors are cheap, but slow. By the time I got two of them and all the hoses/fittings, it might be easier/faster/cheaper to go with an ARB compressor or the like.

In an ideal world, this is the way I'd like to see things work out:

• hard-mount a 12v compressor under the hood.
• run a line from the compressor to a switchable T-fitting
• run an air line from the T-fitting to the front bumper
• have some type of quick-disconnect fitting on the bumper that I could hook an airline to for filling tires, etc.
• run a line from the T-fitting to the air tank stored in the back of the truck. The tank would be removeable so I'd only carry it on trail rides.

4Crawler

iTrader: (3)

I have the entire system documented on my OBA page, which was previously posted. The direct link to the compressor info is at:

12V Compressor info

Its a 2.2 CFM Thomas compressor, airs up all 4 33x9.50 tires in about 6 minutes when connected to my 4Air tire inflator. Has worked flawlessly for the last 6 years. Once installed it has no ongoing costs and I've aired up 5 trucks on one run when the nearest gas station's compressor was out of service and it was about 50 miles to the next air.

Corey

iTrader: (1)

Jackson, either way you go with a good compressor setup, or a C02 tank, you will like it.

I'm partial to the C02 since that is what I have.

At our Fall COlors Run a few weeks back, I aired up my tires from 20 PSI to 35 PSI in just a few minutes total.

Then Jim next to me used my Power Tank, then UKMyers used it to fill two of his, and Rome lent him the Power Tank to do his other two tires.


They were both impressed with the speed and ease of the tank.
The C02 is very fast.

Only drawback is you do have to get it filled, but in general it's good to do about 40 tires from trail to street pressure faster than a service station can fill them.
It's that fast.

4Crawler

iTrader: (3)

One thing I've noticed with the CO2 tanks is whoever has one seems to end up filling more that his tires at the end of a run, since they are somewhat faster. In fact a few runs back, I had to finish airing up one of the trucks in our club that has a CO2 tank, because his had been nearly drained on the previous run since he had aired up several of the trucks in that group. He was able to get 3-35s full, but ran out on the 4th tire.

On my last run, I did use a CO2 tank to refill my tires and found that it was not all that much faster than my on board compressor, maybe took 4-5 minutes instead of 6-7. This was a homemade setup and I think it was starting to freeze up, as it was getting slower on each tire.

Corey

iTrader: (1)

Gosh that was slow Roger.

My line does get very cold at the regulator, but filling my 31" tires from 20 back to 35 PSI takes about 30 seconds or less each.
That was at about 3k foot level too I think we were at, and about 75 degrees.

I'll have to time it for sure next time I air back up.

transalper

You would have to use a high-end electric, engine-driven compressor, or CO2 tank to put out as much air as a gas station compressor. For example, the ARB compressor only puts out .8 or so CFM. The Viair450 I use puts out around 1.6 CFM. 4crawler's thomas puts out 2.2 CFM. I don't know for sure what the gas station pumps put out but I would bet it's in the 4-7 CFM or more range.

CO2 tanks are great, but the big advantage of the electric compressor for me is their compactness. It would be hard to fit a CO2 tank under the hood of our rigs.

I like the idea of the extra portable tank in the back just for trail rides, in addition to a compressor. You could just fill it up before the ride with the schrader valve or hook up a quick connect of some sort. I may have to get one of those.

I had a quick connect on my bumper for a while but took it off because it got way too dirty and corroded (minnesota winters and road salt really took a toll).

Mad Chemist

Transalper,

Just to restate what I think was mentioned above, a portable tank holding just plain old air will most likely not even fill 1-2 tires before it runs out. WATRD has an ARB compressor with a tank, so that the tank pressure is replenished via the 12V air compressor, if I'm not mistaken.

4Crawler

iTrader: (3)

This was 33x10.50 tires (a lot more volume) and at about 6000' and similar temps, from 15 up to about 40 psi.

midiwall

I think we need to define one more aspect here...

Jackson; when you talk about a "gas station compressor" are you talking about the ones that are mounted on a pole away from the station and you drop a quarter into for 10 minutes of air? If so, then those are probably around 4CFM or so.

But, if you're talking about using the hoses that come with a sign "FREE AIR!" and the hose seems to run _into_ the station's service bay through a wall, then you're talking apples and oranges. Those lines are usually connect to the service bay's air supply which is a HUGE tank loaded to about 150psi. The CFM rating would be through the roof from what we're talking about here. You could fill a good sized tire from flat to 32psi in seconds.

The high CFM rating in that case comes from the tank being loaded, not from the compressor itself.

midiwall

I can make this easier for you...

Instead of the T, you're looking for a 4 port manifold. Sears sells one, any hydrualics or pneumatic shop will have them as well. The manifold is basically just a machined aluminum block with 4 1/4" NPT threaded holes in it, and a common channel between all holes.

You'd hook up like this:

• Run a line from the compressor into port 1
• Run a line from port 2 to an air storage tank (at least 2 gallons, 5 is better if you have room)
• Run a line from port 3 that runs up to your bumper, teminate the line with a "universal quick fitting"
• Plug a 150psi pressure switch directly into port 4

What you have at this point is a closed system that will always keep the tank loaded to 150psi. You use air from the fitting on the front bumper, and in this system, you'll draw the air from the _tank_ which is important to get a good CFM rating.

As the tank pressure drops, the compressor will automatically start and work to push the tank back to 150psi.

There's no need to make the tank removable. Shop around (eBay is good) and you should be able to find a large tank thank is long and slender. Mount this under the truck, right behind the rear diff. This is where Rob (WATRD) has his, and it's TOTALLY protected. More than you would think.


Now, all that being said.. It will really only buy your the ability to air tires. The 5 gallons of air in that tank won't go a long way to running air tools, and something like the ViAir 450c (1.6CFM) does _NOT_ push enough air on its own to run a tool.

If you think you want to run tools, then you have to go with CO2 for a truck based system.

jacksonpt

I'm talking about one of those self service stations that (around here), you drop 50 cents into and get 60 seconds of air.

Obviously, a higher CFM rating is better, given the current conversation. But what does psi have to do with all this? A higher CFM rating will push air into the tires faster, right? So what effect on performance does psi have? is psi a function of cfm?

I'm not looking for anything great here... and Roger's setup sounds great, but I don't want to put $500 into an air setup that I only use once a month. I want something that will be easy to use, reasonably fast (i.e. faster than those cheapie compressors they use for basketballs and rafts and such), and reasonably affordable. I don't need to run air tools, just fill up tires - both airing up after a run and fixing flats on the trail.

Transalper - that's a good point about the rust... NY winters can be hell too. I've wheeled with a couple of people who had their air setup this way and it was very slick/handy. Might not be the best idea for me though.

4Crawler

iTrader: (3)

I use th 4-way cross fittings in my 4Air system and have them in stock if anyone needs one. That's the way my air compressor is plumbed, there is a diagram of the setup my my page:

4Crawler

iTrader: (3)

You can get smaller capacity air compressors as well as ones with a lower duty cycle (mine is rated at 100% duty cycle so can (and has) run continuously). I wanted a highly reliable system, the compressor is one thing I don't carry a spare for. And when I got mine (1997) there was no Power Tank system around.

The TruckAir compressor is pretty good for a small portable (especially if you replace the cheapie hose and fitting they use), even talked to one guy that had two plumbed into a small tank and he said it worked fairly well. Teh QA-III is a 3 CFM low duty cycle compressor for about $300, there are others in the $100-300 range.

And I do address the CFM vs. pressure relationship on my page, all compressors will have the flow rate fall off with rising pressure, simple physics of the pump. Good pumps will give flow rate at various outlet pressures, cheaper pumps will typically list the 0psi flow rate (and beware of the subtle trick of using CFH instead of CFM) and really cheap ones will list the max. pressure they put out

For ocassional use the CO2 would be good, although its flow rate does fall off with temperature. Or a portable tank and a TruckAir to refill it. A guy in my club has the ARB compressor and a 5-7 gallon air tank. Not terribly fast, but he can air up the tank on the trail and can fill about 2 of his 32s with it then back to the ARB compressor. Takes him about 15-20 minutes to air up, not fast but its tolerable. He mainly wheels at the local OHV park where they have an air-up station, only uses his air tank a few times a year I would guess. If you were to use a portable tank with a 4-way air hose setup, you would be able to equally fill all 4 tires to the same pressure. May not get you from 15-35 psi, but might get you to 20-25 psi, enough to drive to the nearest gas station to finish airing up if needed.

midiwall

They're related in a weird way.

Compressors are rated at different air flow rates (CFM) for different pressures. For example, the ViAir 450c is rated 1.66CFM at 0psi, 1.34CFM at 30psi, 0.72 at 150psi. So, with the compressor spinning away and nothing restricting the airflow, then it's moving 1.66CF of air per minute. But, if you're filling a tire, then as that tire approaches 30psi, the compressor will drop to 1.34CFM.

When you load a storage tank to a certain PSI, what you're doiing is pushing more air into the tank than it will hold "naturally". If you open an air tank and let it sit there, there's air in it, but it's at 0psi. Forcing more air into it increases the pressure that the air is under. This is where an increased CFM will come into play.

Since you have a "bunch of" air in the tank, under pressure, then if you give it a way to make a _quick_ exit (like through a 3/8" air hose on the bumper) you'll increase the CFM "rating" at the release point. You'll have the help of 150psi worth of pressure trying to force the large volume of air in the tank out of the tank.

In comparison, the CFM rating of a compressor comes from the size of the piston(s) in the compressor and how fast the compressor is spinning the crank and pushing the piston up and down.

Mark