I am switching to non-runflats. Instead of a plastic 12v airpump, I bought one of those Co2 inflators used for bikes & ATV tires. I tested it on a flat and I figure it will take about 6 of the 12 gram cartriges to fill a corvette tire, but I put 8 in my kit just in case. I noticed tho, the cartridge ices up if I fill to fast. Once I pull the trigger it dumps the whole charge in a second or two. So I wondered if the cold or the Co2 will affect the sensor. This is just for the emergency flat repair, so once able I would remove the Co2 and reinflate with USDA approved air. I like the inflator as it takes up no space and the cartriges are cheap. I used it on a flat bicycle tire and it was instant. It also works with the larger 16 gram cartidges but I havent found any of them yet. The 12 gram size is available at wallmut, 15 for about $8. Does Co2 expand more than air as it heats up? Someone on the forum must have a backround in science, maybe you can advise.

 

Sounds like a good plan, the chilling shouldn't be too hard on the rubber if you wait a minute or two between charges, or is there any way you could meter the incoming charge?

Another advantage is the C02 will be dry. Don't think it's going to react with anything, either.

HTH, and have a good one,
Mike

 

USDA -- U.S. Dept. of Agriculture.

what exactly is USDA approved air?

 

The device has a trigger on it so I probably can regulate the fill somewhat. I was just amazed on how fast it worked. The inflator has a screw on nozzel and the base unscrews so I can take out the empty and insert a full one. If the schrader valve on the tire doesnt ice up solid I could refill the tire in a couple of minutes or so. As far as USDA air goes, only the good air for vette tires we dont want none of that ordinary stuff.

 

I gotta ask, why you just don't use one of the small 12 VDC air pumps you plug into the lighter? They are real cheap and do the job well. I use mine everytime I go autocrossing.

 

I don't believe that the cold CO2 will negatively affect the sensor. CO2 is relatively inert and chilling down the IC chips in solid state devices is one way to see if the IC chips are bad since the cold often brings them back to life (used to use freon in the old days)

 

I guess because the last one of those I had didnt work very well and took awhile to pump up a totally deflated tire. The one I also had for some air shocks on a truck took forever also. They say 200 psi & up but they ought to come with a calander as well. Again I am talking about inflateing a totally flat tire. Maybe now they are made better, but then theres the wire to the closest power plug and they take up a bit of room. The Co2 inflater is about the size of a large cigerette lighter, is really portable, not a whole lot more in cost (well figure at least double as you gotta buy the Co2). The space that would be used by the elec pump is where I put the nifty alum jack I (and about 300 others) got from the forum member in Germany. (I wonder what hes up to these days?) I also like it for inflating the other household tires like lawn mowers ect. Fast and easy. I thought about adapting one of the cylinders they use for paint ball guns but wasnt sure what size would work and there would be a small problem with and adapter for the tire valve. As I said earlier 6-12 gram cartridges should do it but I will carry 8. I still may try a total deflate on a rear just to see exactly how many. I get my wheels back from the powder coater in two weeks so I can do it when I mount the tires. As an aside isnt the Co2 the same stuff used for fizzy drinks and soda water. Now if I can figure out another adapter.........

 

Yes, and Coors uses it to push the beer out of its kegs. Also, some bars/resturant dispense house wine out of a tap but in that case they use nitrogen instead of CO2 as CO2 and wine don't get along

 

I guess I could fit a pony keg in the center cargo hole, but the weight of the ice to cool it would slow things down on the autocross. But sometimes sacrifices need to be made in times of necessity. Decisions decisions.

 

that actually sounds like a good idea.
i don't have run-flats either and it's always been a concern. the main reason i never bought one of those 12v jobs is for exactly the same reason you stated. you could just about kill a battery trying to air up a flat tire.

 

I would assume USDA air would NOT have any oil traces in it, i.e. come from an oil-less compressor. Just guessing.

 

I sell home soda dispensers, they all use CO2 gas. The CO2 is stored as a liquid and converts to a gas at the top of the tank. We use regulators to control the pressure.
On a hot day in your (trunk) the CO2 will be at 1100 PSI or better. I am not sure I would want that in my car. The safty valve can blow, and depending on the size of the tank, it can blow your windows out, or just scare the crap out of you, and while you are driving... that could be bad.
I guess if you use just the small ones, like BB guns have, it can't do too much damage.

 

This is actually a pretty intriguing concept. If you can keep the temperature drop under control (remember C02 is used in some fire extinguishers) I can think of no reason it shouldn't work.

It would be interesting to see how many cartridges it would take to fill a tire.

Have a good one,
Mike

 

I will most likely find out in the next couple of days. I plan to deflate one of the rears to see. I have to rebattery or replace the air pressure sensors anyway as I sent my stock fronts and wider aftermarket rears to the powder coater and will mount the nonrunflats when they get back. So my curiosity will get to me before then so I may as well find out now & post the results. Stay tuned.

 

Using CO2 in tires should not be any problem. There are a lot of CO2 rigs for sale just for that purpose. Off-roaders use them a lot. Many Hummers have a CO2 based system for the on-board inflate/deflate system. Most car systems don't use it only because it requires at tank and its just easier and cheaper to suck in ambient air and compress it.

 

Nah, It is just similar to GM approved air without the pricetag. I get my tires mounted this saturday, so I will know how many 12 gram cartridges it will take to fill a 295/35/18