Using Nitrogen Versus Air for Race Tires

[gran racing]

I recently purchased some Kosei rims and thought it was a bit odd that there are two valve stems. I asked Mike Glassburner (whom I bought four of them from) why they have two. He indicated that it was to make purging air out of race tires easier in order to replace it with nitrogen. Hmmm. I’ve seen it at the track, but never gave it too much thought. Later that night I was over at a friends house yelling and pointing my fists at my Prelude, I mentioned this. Grant explained the basic purposes and advantages of using nitrogen versus air, and even told me about a local shop that I could get a bottle from cheaply.
Nitrogen is moisture free thus provides a more constant rate of expansion and contraction. Some people also state that tires also run cooler when nitrogen is used. Assuming someone doesn’t mind the additional cost, any inconvenience of using sourcing nitrogen and bringing a bottle to the track, are there any other down sides to doing this? When towing, are there any DOT regulations that I should be aware of when transporting nitrogen that may make this a PITA?

Since it’s a Friday and I started this thread, I suppose it’s o.k. for me to vear off-topic a bit. Besides, it’s a “how nitrogen is used in packaging beer” diversion. :D Just thought this was interesting…

“Guinness is canned with a mixture of carbon dioxide and nitrogen. Nitrogen is not absorbed into the beer nearly as well as carbon dioxide, so even though a can of Guinness may be at the same pressure as a can of lager, it contains less CO2 (and is therefore less fizzy) because the nitrogen makes up some of the pressure.

Because a beer like Guinness contains less dissolved CO2, if you poured it from a can with no widget, the head would not be very thick because most of the CO2 would stay dissolved.
The purpose of the widget is to release the CO2 from some of the beer in the can to create the head. The widget is a plastic, nitrogen-filled sphere with a tiny hole in it. The sphere is added to the can before the can is sealed. It floats in the beer, with the hole just slightly below the surface of the beer.”

[Greg Amy]

Mmmmmm. I like beer.....




http://itforum.improvedtouring.com/forums/...587&hl=nitrogen (http://itforum.improvedtouring.com/forums/index.php?showtopic=6587&hl=nitrogen)
http://itforum.improvedtouring.com/forums/...201&hl=nitrogen (http://itforum.improvedtouring.com/forums/index.php?showtopic=201&hl=nitrogen)

[tom_sprecher]

Bottles and regulators are cheap (I bought both for $100 used), can be exchanged were you get the various gases for welding and real handy at the track. Strap it up to the wall of your trailer (they make racks for the very purpose) and you can run impact wrenches as well.

Also, in one of the threads Greg was kind enough to search out someone asked if nitrogen was lighter than air. Put it this way, air is nitrogen, or 70% of it is anyway, so the answer is no.

BTW: From Wikipedia, my favorite source of quick and to the point info...

"Draught Guinness and its canned counterpart contain nitrogen (N2) as well as carbon dioxide. Nitrogen is very much less soluble than carbon dioxide, which allows the beer to be put under high pressure without making it fizzy. The high pressure of dissolved gas is required both to enable very small bubbles to be formed and to force the draught beer through fine holes in a plate in the tap, which causes the characteristic "surge" (the widget in cans and bottles achieves the same effect). The perceived smoothness of draught Guinness is due to its low level of carbon dioxide and the creaminess of the head caused by the very fine bubbles that arise from the use of nitrogen and the dispensing method described above. "Original Extra Stout" tastes quite different; it contains only carbon dioxide, causing a more acidic taste."

Personally, I don't care for dark beers, but to each his own, so don't start about weak American beers (Bud Light is my favorite) because I've heard it all before. I just don't like the flavor, period.

Other foods (like potato chips and the like) are packaged using nitrogen to extend shelf life that would be reduced by oxidation. I sell captial equipment used in part for food packaging and you would be amazed at some of the technology used. For example, the film in a simple potato chip bag is usually 7 layers of co-extruded or extrusion laminated polymers carefully chosen to achieve certain properties. Many times the package costs more than the product but unless you buy fresh food that's the price (and my commission) you pay. ;)

[gran racing]

I should have searched. Sorry! Good thing I added the beer part to my post.

Greg, what have you learned about traveling to the various tracks with Nitrogen (DOT rules)? You also have the benefit of an enclosed trailer to store it.

Are you still using Nitrogen?

[Greg Amy]

I still use nitrogen exclusively. It's about $25 to exchange a 22 (?) cubic foot tank, which lasts for purging about 6-8 total new tires or about half a season of event top offs.

No clue on DOT; never researched it, never been challenged on it. I'm a private party doing non-commercial stuff, so I imagine no one really cares (and if I did get pulled over, they'd probably have a cow over the four 5-gallon cans of gasoline hanging off the wall...)

I just make sure it's properly secured during transit.

[MMiskoe]

As best as I know unless you are carrying huge quantities of it, I don't think there are any DOT regs on it outside of it needs to have a safety cap on it. That is just common sense.

Not to sound like sargent safety, but them bottles are potentially lethal. Treat them w/ respect, keep them tied up and caps on.

[tom91ita]

doesn't the use of nitrogen go completely against the premise of your book and racing on a budget?

[keycom]

DOT says "secured in an upright position". No HazMat permit required.

[JLawton]

Not to sound like sargent safety, but them bottles are potentially lethal. Treat them w/ respect, keep them tied up and caps on.
[/b]
Yeah, didn't you guys see the Mythbusters episode where the knock the valve off and shoot it through a concrete block wall?? Cool stuff!! :035:



doesn't the use of nitrogen go completely against the premise of your book and racing on a budget?
[/b]

Ohhhhhhh, Ya gonna take that Dave?? :bash_1_:


Of course, at $22 for a refill, I don't think it's that outrages.............

[tom_sprecher]

doesn't the use of nitrogen go completely against the premise of your book and racing on a budget?
[/b]

Cheaper than an "at-the-track" air compressor.

[gran racing]

doesn't the use of nitrogen go completely against the premise of your book and racing on a budget? [/b]

Now that's some funny shit. Har, dee, har, har. Actually, since you asked I talk about different phases in a person's racing career. The first is simply to get out on the track, get as much seat time as possible, and concentrate on improving one's driving skills / racecraft. I started off towing to NHIS (now I did NOT say this in my book since I look back and say WTF?) with a 4 cyl. Jeep Wrangler, and using a tow dolly. Once I got to the track, I drove on and found a little side road that had a dirt path and set-up camp. No joke. Looking back I now wonder what I was thinking. Oh yeah, I wanted to race. Even in '05 at the ARRC, my wife and I were just about the only fools to camp (save $$$$). Later on in my book, I have a chapter titled "Moving On" which describes the next steps in a person's racing career. This year I found a PCA driver who was selling his nice open trailer (with brakes and in nice condition) for $500. Sold the dolly for $450.

I&#39;m in the "Moving On" stage now. Does it cost money for me to reach this phase? Yup! I got a part-time job at <insert another plug> InControl Website (http://www.incontroladt.com) to help fund my addiction.

On the way home tonight from work, I thought of all the items I&#39;m doing this year to improve upon my new Prelude and myself as a driver (getting at least two coaching days this year, including at Mid-O). Give me a few races to get things sorted out and I&#39;ll be passing you in your ITA car Tom. :P Oh, you might find my chapter on obtaining sponsorships helpful. Nitrogen cost? Lease the bottle and racers get FREE Nitrogen refills as long as they put decals on the car. Not bad, eh? That information alone would more than cover the cost of my book.

Hey, thanks for the plug!

[Spinnetti]

I think we need a "myth busters" on this...

I could be ignorant here, but highschool chemistry says PV=nRT (google it for details). I don&#39;t see how N2 is gonna be any different than regular air in its expansion rate.

[Gary L]

I think we need a "myth busters" on this...

I could be ignorant here, but highschool chemistry says PV=nRT (google it for details). I don&#39;t see how N2 is gonna be any different than regular air in its expansion rate. [/b] It&#39;s about the moisture, or in the case of bottled nitrogen, the lack thereof. Side benefits - there is no oxidation (corrosion) to worry about, and theoretically, a nitrogen filled tire holds pressure longer than one with plain air in it... the molecules are fatter. The aircraft industry (to include the military) has been using nitrogen in tires for years, for these and other safety-related reasons.

[tom91ita]

i wasn&#39;t trying to give you grief, just asking a question.

i never spend money on air, except for the $19.95 investment i made in an air bottle when i started autocrossing a few years ago. i am typically walking through the paddock looking for the tire trailer to top off for the weekend.

one thing i don&#39;t like about the nitrogen bottle in the trailer is purely cause i sleep there sometimes.

and with regards to setting up camp on the side roads, you might consider the walmart parking lots. i&#39;ve spent more than one night there (most recent was last weekend). has the advantage of being open 24 hours with restrooms.

worst night ever was staying over at IRP in my crx for my quarters. it was for my second driver&#39;s school. drove the car there and then hunkered down in the car when they locked the place up cause no camping was allowed at the site.

did not sleep well but did not spend any $$ either.

congrats by the way on the scca ties to your book.

oh, and technically, now i am itb. just never changed the handle. the crx was reclassed but i was too cheap to sell the car. hopefully we will cross paths some day.

if the beer is free at the saturday night party, i&#39;ll buy you one. :birra:

[Sandro]

For the DOT rules I know at work we dont have to placard unless its over a certain weight, and its alot I think around 500lbs. I know we are "supposed" to carry paper documentation with us, that is in arms reach so if you decide to flip your vehicle or catch it on fire you can grab it and show the fire man trying to put out the blaze what to be aware of.


I will ask the Dangerous Goods specialist at work what the exact rules are and get back to you guys.

[gran racing]

Bringing nitrogen would be fairly easy for someone with an enclosed trailer. Are there many of you who tote it around the bed of your pick-up or other tow vehicle?

[JimLill]

BTW........ the second stem is for an inner liner tube/tire in some cases...........

http://www.vectorbd.com/users/jpl/vwpix/slides/vwsil7.jpg

[Spinnetti]

It&#39;s about the moisture, or in the case of bottled nitrogen, the lack thereof. Side benefits - there is no oxidation (corrosion) to worry about, and theoretically, a nitrogen filled tire holds pressure longer than one with plain air in it... the molecules are fatter. The aircraft industry (to include the military) has been using nitrogen in tires for years, for these and other safety-related reasons.
[/b]


Sorry.... go fish....

Corrosion? from Air? Sorry, not a factor. n2 is not "Fatter" than all the stuff that makes up air either.
Seriously, this is why some study is required.

Not sure why moisture would be cared about except it weighs more than without, but just put real cold air in - the colder the air, the less moisture it holds. Even so this is insignificant compared to other factors on the car, or about the driver..

[AntonioGG]

Spinetti,

We kind of hashed through some of the same arguments in this thread:

Warning, very nerdy thread:

http://forum.specmiata.com/cgi-bin/ultimat...0009;p=0#000000 (http://forum.specmiata.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=39;t=000009;p=0#000 000)

[JimLill]

http://theforcethat.blogspot.com/2007/02/n...-for-tires.html (http://theforcethat.blogspot.com/2007/02/nitrogen-for-tires.html)

[tom91ita]

the oxidation rate can be an issue. the rate is proportional to the partial pressure of the gas. for the outside of the rim, this is typically 3 psia for oxygen (21% of 14.7 psia). or if you want to compensate for your elevation, go to http://www-personal.usyd.edu.au/~gerhard/pressure.html

in tires that are about 35 psig, the O2 partial pressure is about 10 psia (21% of (35 + 14.7)). so the corrosion rate inside the tires would be about 3 times typical. this is one of the reasons that alloy rims are more prone to losing air than the old trusty steel rims. the aluminum oxidation products interfere with the seating surface, etc.

the increased oxidation due to partial pressures is one of the contributing factors to the deaths due to fire in the Apollo 1 capsule. they had pure oxygen inside and were also pressure testing the capsule to ~15 psig to simulate the pressure difference due to the vacuum of space. they now had the partial pressue of oxygen at 30 psia or ~10 times normal. some metals will burn under these conditions. and burning is just a very nasty form of oxidation.

arguably not an issue with the race tires since we are checking pressures so often and changing tires more frequently(?).

with regards to moisture, it is not the fact that there are a few drops present as much as it that any moisture in the tire will evaporate when it gets hot and add more pressure. the PV=nRT holds true but we are adding more "n" when the drops turn to vapor. there is less moisture in your compressed air since the water in a vapor form is related to the partial pressure related to the temperature. cold winter air will help but during a hot humid day, more water should be condensing in your compressor&#39;s tank (and why we need to drain them).

and since the molecular weight of N2 is 28 vs. O2 being 32, i am assuming that with a larger electron cloud, the O2 is fatter but at this point, i really don&#39;t care. but if we are actually talking about the relative difference between the specific heat capacity of the gases, this small difference is likely dwarfed by the mass of the rim and the tire.

i personally use my practice & qualifying sessions as a time to estimate my heat/pressure gain for that track on that day at those ambient conditions. i then go with three columns for the air pressure (start, projected, actual). if the actual ends up higher/lower than i had wanted/projected, i adjust the starting pressure.

and then there is the whole thing regarding tire temperatures being the better guide, etc. and the fact that i don&#39;t want to bother putting nitrogen cylinders in and out of my hatchback daily driver or haul the rig to the gas supplier to keep it in the DOT required upright position.

p.s., i do have a cordless impact.

[Spinnetti]

the oxidation rate can be an issue. the rate is proportional to the partial pressure of the gas. for the outside of the rim, this is typically 3 psia for oxygen (21% of 14.7 psia). or if you want to compensate for your elevation, go to http://www-personal.usyd.edu.au/~gerhard/pressure.html

......
[/b]


Ok, that was more interesting, but the reality is in the greater scheme of the normal material world of cheap race cars and so-so drivers, it doesn&#39;t make a bit of difference. Why not just run some of those pressure setting valve caps, or as you mentioned learn how much pressure your tires typically gain from temperature rise and set them accordingly?

Anyway, more power to those that want to do it. I&#39;d have it done when I have them mounted at the shop simply because they will do it for me, but I sure won&#39;t be worrying about it at the track!