12v tire inflator

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John Stimson
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Re: 12v tire inflator

Post by John Stimson »

Marshall, have you tried the CO2 in practice? It seems like there is so little mass of CO2 that it would come to ambient temperature quickly.

Also, because the critical point of CO2 is 88 degrees F, under most conditions we deal with in autocross there's almost no heat of vaporization to chill the CO2 as it evaporates. Almost all the cooling comes from gaseous expansion according to PV=nRT, the same as you would get with nitrogen stored at the same pressure.

I'd expect you could fill the tires to just below the target pressure, then walk around a second time and adjust to exactly where you want it.
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Jayson Woodruff
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Re: 12v tire inflator

Post by Jayson Woodruff »

I went years just filling my air tank at gas stations and buddy houses every couple months.

A Viair is one of the two compressors I actually believe in.

Jay W
Bobby Beyer wrote: The airtank route gives me an excuse to buy an air compressor for my house, but as I am already the @sshole car guy, that may not be the wisest decision.

The Viair pumps look decent but I'm still not quite sold on them since it seems most of them have a duty cycle in the 33% range which seems like I would overheat it if I had lots of air to pump on all 4.
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George Schilling
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Re: 12v tire inflator

Post by George Schilling »

Jayson Woodruff wrote:I went years just filling my air tank at gas stations and buddy houses every couple months.

A Viair is one of the two compressors I actually believe in.

Jay W
Bobby Beyer wrote: The airtank route gives me an excuse to buy an air compressor for my house, but as I am already the @sshole car guy, that may not be the wisest decision.

The Viair pumps look decent but I'm still not quite sold on them since it seems most of them have a duty cycle in the 33% range which seems like I would overheat it if I had lots of air to pump on all 4.
Best place to fill the tires on the run? Costco. It's nitrogen and its a free service. Just pull up at the tire bay and tell them the pressure you want. Membership not needed.
CASOC Autocross Club, 1984 Van Diemen RF-84, 1600cc Kent, Hewland Mk9, Centerline 2 pc. wheels, Hoosier R25B, SuperTrapp, Zimmer Alloclassic titanium left hip w/Metasul LDH chromium-cobalt lg dia head
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Marshall Grice
Former CSCC Overall Champion
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Re: 12v tire inflator

Post by Marshall Grice »

John Stimson wrote:Marshall, have you tried the CO2 in practice? It seems like there is so little mass of CO2 that it would come to ambient temperature quickly.

Also, because the critical point of CO2 is 88 degrees F, under most conditions we deal with in autocross there's almost no heat of vaporization to chill the CO2 as it evaporates. Almost all the cooling comes from gaseous expansion according to PV=nRT, the same as you would get with nitrogen stored at the same pressure.

I'd expect you could fill the tires to just below the target pressure, then walk around a second time and adjust to exactly where you want it.
not for filling tires, but for air shifters. we could get frost on the regulator if we tried shifting a lot. I suppose if you had a bottle heater (like the sun) it would work better.

CO2 was rumored to be at least one of the gasses F1 was using to fill their tires with. Although it could be interesting if there is any moisture inside the tire to mix with the CO2 and make carbonic acid.

for autox i'm sure any of the solutions proposed are acceptable.
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Bobby Beyer
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Re: 12v tire inflator

Post by Bobby Beyer »

Marshall Grice wrote: not for filling tires, but for air shifters. we could get frost on the regulator if we tried shifting a lot. I suppose if you had a bottle heater (like the sun) it would work better.

CO2 was rumored to be at least one of the gasses F1 was using to fill their tires with. Although it could be interesting if there is any moisture inside the tire to mix with the CO2 and make carbonic acid.

for autox i'm sure any of the solutions proposed are acceptable.
Yeah, I used to paintball and before I switched to HPA, the regulators would freeze up and stop working after a long burst, pretty annoying when you're pinned down. Funny enough though I have a N2O bottle heater but I have no idea how well that would work with CO2.

I'm going to pickup and airtank and use the compressor at my work for the time being, before I decide to either get a compressor for my place or go with a little tire compressor.
"Promise mediocrity. Deliver just slightly better." - Jarrett Bellini
Jay Balducci
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Re: 12v tire inflator

Post by Jay Balducci »

Several of us over in AZ use this high volume 12V compressor available at both Amazon and Pep Boys for under $60. I've had mine for ~ 6 years.. works excellent.

http://www.amazon.com/Industries-MV50-S ... compressor

http://www.pepboys.com/product/details/9357343/00659/
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George Schilling
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Re: 12v tire inflator

Post by George Schilling »

Jay Balducci wrote:Several of us over in AZ use this high volume 12V compressor available at both Amazon and Pep Boys for under $60. I've had mine for ~ 6 years.. works excellent.

http://www.amazon.com/Industries-MV50-S ... compressor

http://www.pepboys.com/product/details/9357343/00659/
I mostly use nitrogen now that I'm towing and have my truck at events. But before that, this compressor was my mainstay. Works great and is fast. Not as fast as an air tank however. But, unlike and air tank, it never runs out of air. :P
CASOC Autocross Club, 1984 Van Diemen RF-84, 1600cc Kent, Hewland Mk9, Centerline 2 pc. wheels, Hoosier R25B, SuperTrapp, Zimmer Alloclassic titanium left hip w/Metasul LDH chromium-cobalt lg dia head
Bill Schenker
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Re: 12v tire inflator

Post by Bill Schenker »

George Schilling wrote:...Just like me, it never runs out of hot air. :P
Fixed that for ya', George. Happy New Year.
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George Schilling
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Re: 12v tire inflator

Post by George Schilling »

Bill Schenker wrote:
George Schilling wrote:...Just like me, it never runs out of hot air. :P
Fixed that for ya', George. Happy New Year.
Thanks Bill! :lol:
CASOC Autocross Club, 1984 Van Diemen RF-84, 1600cc Kent, Hewland Mk9, Centerline 2 pc. wheels, Hoosier R25B, SuperTrapp, Zimmer Alloclassic titanium left hip w/Metasul LDH chromium-cobalt lg dia head
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