air tank for autox - 5 or 10 gallon?

Need to buy an air tank for autocrosses. Looks like there are 5 gal and 10 gal versions. Is 5 gallon enough or will I wish I had the 10?

If size and space are not a major concern, I would go with 10 gal. Even better if you can find one that goes to 11.

If you do not have a compressor at home, the challange is in finding a public place to fill a tank to psi of higher than 60. Most gas stations can do no more than filling a bike tire - if that. I have a few garages near me that I visit to fill my tank up to 100psi.

I use a 5 gallon, which I believe is rated for 120 psi and it has always been sufficient for my needs. Remember, you're not going to be filling empty tires, just bumping them up a bit.

5 gal 135psi here and it's always gotten the job done, and then some.

at the risk of sounding foolish, why not just bring a compressor to the autox?

I have brought both at different times, the air tank is by far the easiest and fastest. I do have a tiny little 12v volt that works rather well too, and takes way less space. Most times the size of my air tank in the Miata doesnt matter, I have the room. Mine is a hand me down tank that is prolly 30 years old and I believe its a 10 gal

thatsnowinnebago wrote: at the risk of sounding foolish, why not just bring a compressor to the autox?

You'd have to plug it in somewhere, and a 5 gallon tank is easier to haul around.

thatsnowinnebago wrote: at the risk of sounding foolish, why not just bring a compressor to the autox?

I used to do that.

5 Gallon tanks are fast and quiet.

I just bring a foot pump. Not kidding. Works fine.

I have what I think is a 10 gallon. I wish it were a 5. I've never needed the extra capacity the 10 has.

.check out an aluminum one. They are a lot lighter and easier to handle.

I have a 10 gallon unit. It takes forever to fill, but the added capacity is nice when you want to be able to share your air with your neighbors (unless they're in your class). No problems fitting it in my Miata either.

I have an aluminum 7 gallon that is awesome! Light weight, and it's always had enough to top off my tires, even if I can only get it filled to 70 PSI (what the local station seems to be caped at).

confuZion3 wrote: I have a 10 gallon unit. It takes forever to fill, but the added capacity is nice when you want to be able to share your air with your neighbors (unless they're in your class). No problems fitting it in my Miata either.

I took the hose off of my 5 gal tank and replaced it with a quick coupler. Then I built a double male fitting with a shut off valve. Connect compressor to tank, open the valve, and watch the gauge. Easy!

thatsnowinnebago wrote: at the risk of sounding foolish, why not just bring a compressor to the autox?

+1

Takes up less space and works just as well as the big tanks. I used both and now just keep the compressor in the car. I use this one: http://www.c2racers.com/servlet/the-328/Viair-Portable-Tire-Compressor/Detail

The owner of that place is a San Diego autocross champ fwiw

Those 12v. compressors are slowwww.

I have a little 3 air compressor that I use with my nail gun. I was considering lettin git fill up and brining it to autoxes with me. It probably only weighs as much as 5 gallon tank. If it gets empty, most of our local sites have a place that I could plug it in. Or I can use my little 12v one as a backup.

I got this one on sale several years ago for under $40.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94801

It takes 160psi. I use my 60 gallon 150psi IR upright compressor to fill it. I like the idea of adding a double fitting so I can use the full CFM on my compressor to fill it. It gets a little tedious going through the "fill valve".

I now know what I'm doing this weekend!

A slight theft of the thread and stupid question time...

Anybody ever make an air tank out of an LP gas tank? I've got one of those with the out of date valves and thought about making an air tank out of it.
Comments...

thatsnowinnebago wrote: at the risk of sounding foolish, why not just bring a compressor to the autox?

I've gotten by doing that for years. However, there have been countless when I've wanted to make an air pressure adjustment and didn't have time to make it between runs.

I've seen it done with an aluminum LP gas tank like on the back of a forklift. It is big and light weight.

Go with the best of both worlds. Get a small air tank and a small compressor. Use the tank to fill the tires and the compressor to top off the tank when it get low.