I'm planning on switching to Nitrogen in my track tires to remove the water content (and all the related bad results). I was doing some research at a welding shop and these are the prices quoted:

20 cubic foot tank (full): $135
Oxygen regulator (converted to nitrogen): $110
Hose: few bucks

Is there a cheaper way to do this? Has anyone purchased a used regulator and converted it?

 

what "bad" results are you trying to remove? cost? flexibility? a dryer on your compressor can take care of water content, so all you're left with is pressure change due to temperature change. seems like an expensive solution to a problem that already has a cheap solution.

nate

 

Are you running bias-ply slicks? If not, going to nitrogen is probably a waste of effort and money. Just put a dryer on your compressor.

 

Well, I don't own a compressor, or a dryer - so I'd need to lay out the money for these items.

Do you take the compressor/dryer to the track? If you're using air supplied at the track it has a notoriously high water content. When water heats, it expands. Assuming you've put different amounts of track air in each tire, and assuming you heat each tire the same amount, you'll get different hot pressures in each tire.

I'm trying to reduce the variables. Nitrogen is something like 99.9% water free. Hot tire pressures will not change as much as air, and will change consistently.

 

Honestly, I don't worry about it. I don't dry my air and I occassionally use track air (like when my roommate empties my air pig). I just check my hot psi every so often and go from there.

 

I run helium to reduce my unsprung weight.


Matt

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pcorad &raquo;</TD></TR><TR><TD CLASS="quote">Hot tire pressures will not change as much as air, and will change consistently.</TD></TR></TABLE>

Fallacy.

Dry Air Gas Constant: 0.2870 kJ/kg-K
Nitrogren Gas Constant: 0.2968 kJ/kg-K
Steam Gas Constant: 0.4615 kJ/kg-k

It's the water that causes different rate temperature increase, not the air.

Dry air vs. nitrogen is the only issue here. I'll bet dry air is MUCH cheaper.

Andy

 

You could be right. I don't know anything about kJ/kg-K...

I was referring (though I didn't state it) to the water content in your basic New England air, which will change drastically depending on the humidity levels.

 

forget nitrogen, I run Nitrous. naaawz y0!

 

It is true that if the air is contaminated with water, the whole will expand at a different rate. The constants posted above assume dry air. I think the problem you should really be trying to solve is different air/humidity content in the tires to ensure consitent hot pressures. The water content in the air is not really the problem as such, it's the difference in water content that's important. For example, because you may have filled/adjusted you tire pressure under different atmospheric conditions, each one will have slightly different water content, so that you may see 38/39psi hot on a given pair of tires. Let's say for example if the water content was the same, you may have seen 39/39 psi on the same pair or 38/38...

I dunno, but maybe the cheapest solution would be to deflate all the tires and fill them with the "air du jour" on race day? And then fill your air tank with the same air to bring to the track? This way all four tires will expand at the same rate.... Just an idea...

Then you can spend the money u saved to buy that really pimpy new part...

 

See, Matt you might go faster if you didn't use Helium in your tires. Helium molecules are small enough to slide out of the tire by slipping between the rubber molecules. Now, I'm not sure here, but I'd bet some JDM burgergrease into the tire prior to mounting would have an adequate film-strength to resist penetration by the helium...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WRXRacer111 &raquo;</TD></TR><TR><TD CLASS="quote">See, Matt you might go faster if you didn't use Helium in your tires. Helium molecules are small enough to slide out of the tire by slipping between the rubber molecules. Now, I'm not sure here, but I'd bet some JDM burgergrease into the tire prior to mounting would have an adequate film-strength to resist penetration by the helium...</TD></TR></TABLE>

I see the crank availabilty is good in Miami! Lay off the pipe y0!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crack Monkey &raquo;</TD></TR><TR><TD CLASS="quote">Honestly, I don't worry about it. I don't dry my air and I occassionally use track air (like when my roommate empties my air pig). I just check my hot psi every so often and go from there.</TD></TR></TABLE>

Fah-Q!!!!!!

Dan

 

Isn't atmospheric air damn near 80% anyway? We used nitrogen on one of our cars (because the driver liked to run his air tools with it so it was handy) and I saw no practical benefit at the time. It was a sports racer on slicks and the variance that the driver introduced into the equation WAY outweighed any possible gain in temp/pressure change from spending $$ on air.

Kirk

 

Nitrogen, ha. I use Whipped cream in my tires. Not only does it smell better, but it tastes better, too.

 

Food for thought: http://bbs.sccaproracing.com/u....html

 

Basically Bob Vilven answered the question: nonfiltered air is the problem - those coin-ops don't have water separators like all compressors usually do. If you have a race budget, go ahead with the cylinder. Or just don't fill up at the quickie mart.


Modified by 4WDrift at 6:31 PM 4/17/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4WDrift &raquo;</TD></TR><TR><TD CLASS="quote">Basically Bob Vilven answered the question: nonfiltered air is the problem - those coin-ops that don't have water separators like all compressors usually do. So don't fill up at the quickie mart. </TD></TR></TABLE>

D'oh.......