looking for recommendations on a simple portable air tank that i could use to tweak my tire pressures at autocrosses. ive seen people with them before and i was just curious.

 

sears $40 9 gal.

harborfreight has a 5gal for $20, but you need the extra 4 gallons.

 

yeah? and how do they work? do you refill them when they run out? where would you refill them?

 

just plug it to a air compressor (gas station) like you would a tire and it fills up, and then you dispense with the flexible nozzle. works fine, however mine doesnt hold air past 24 hrs. just gotta remember to fill it BEFORE you get to the track.

and ill add that a portable air tank is MUCH better than a cheesy 12v compressor that makes a lot of noise and takes forever to get even 1 psi out of. keep those things in the trunk for emergency only, cuz they only have so much life anyway until they break. money better spent with a air tank for real track use.


[Modified by Tyson, 4:55 PM 8/10/2002]

 

great! thanks for the info~

 

How many tire adjustments (~5 PSI) do you get on a full tank? I hear not much past 4?

 

depends on how much you fill the tank. but one of my race tires was pretty flat and when i filled that one tire up with the air in my tank, it pretty much got it down to 30psi, which the remaining air is useless, and ended up having to borrow someone elses... kinda lame huh to show up with a tank and have to still beg for a toot. i tihnk it was full up to 80. it can hold a lot more, like 150psi, but like i said, you need that extra 4 gallons the sears model gives. now the nice aluminum ones... mmmm..... the sears one is a bit heavy to walk long distances with. it does come with a pressure gauge tho. fill it to 100psi and im more than fine for the day. just no filling empty tires.

 

Well if the track has air, filling the tank is still way more convenient than driving to the air.

 

Yep, get a big tank. i have a 7 gallon tank and wish it were bigger some days (wal mart, $17) but for the price you cant beat it. Once the pressure in the tank gets close to the pressure of the tires (~40psi) the tank is pretty much useless in filling them up. The big problem i have is finding gas stations that dont charge for air and dont have busted *** air chucks that i cant fill the tank with.

RJ

 

Corey and I got a full weekend off my Craftsman tank without a refill. Note though that I show up with my Hoosiers slightly overinflated, so I can quickly bleed off pressure (rather than slowly adding it) when I get to the track.

 

I have the same 7g tank, but I also have 4g pancake tank with compressor, it will fill up to 120psi, but over 100 it is slow. I am working on a T setup so I can run air tools off both tanks.

 

yeah i usually overinflate my tires and then take some out as i need to.

 

i've got a 120 psi tank but all the gas stations around here only have enough power to fill it up to 80 psi. also, once it gets down to 38-40 psi it doesn't fill anymore because the pressure is about equal of the pressure of the tires. so really that only gives you about 7-8 psi per tire. thus, i try ot have my tires about right before i leave and then use the tank to adj pressure both days at the track

 

quick tip, add a disconnect between the valve and hose on the tank.



this allows you to conect DIRECTLY to home compressor for a quick fill. Also with a extension hose (male connectors on each end) you can run a impact to change tires. I can change 4 tires, adjust tire pressure in slicks (12-13 psi) and rear tires (60 psi) and still have enough left over to change tires back for trip home. This is with a 10 gallon tank.

Also when not in use and left connected to main compressor/tank (teed) I go from a 20 gallon to 30 gallon tank capacity plus tank is always full. Just close valve and disconnect.

The ONLY downside is if hose is disconnected and valve on tank left open, it will empty itself. You can see in picture where I wrote in marker on tank to not do this.

 

I also went with the 7 gallon "Wal-Mart special". It's been ok so far. Any bigger and it would sort of cumbersome to pack.

This probably sounds a little on the obvious side, but tank pressure made a bigger difference than I thought. If I fill the tank up to 120 lbs, it lasts an amazingly long time. Filled to 70 lbs or so, and it drained after just a few tires (duh). But I was surprised at the difference.

 

I got a Sears one several years ago, but due to the crappy gas station compressors, I gave up on it. Took forever to fill it up to just 70 psi. Then I got my own compressor in my garage

I'll never use one of those 12v pieces-of-crap again. Fill it up to 90-100 psi and it's plenty for an autocross or track day.

Only downside is it take up more room in my trunk than the small 12v compressor.

 

just wish i had a home compressor....