Using Nitrogen? Please step inside...
11-08-2007, 02:24 PM
#1
Le Mans Master
Thread Starter
Using Nitrogen? Please step inside...
OK, so a buddy of mine got Nitrogen at his shop and told me he would fill my tires at no cost. I know they use nitrogen in many race series and would be interested in trying it at the track next year.
Now the tricky part...R compounds like Hoosier or 710's have cold and hot recommended pressures. I usually start cold around 30-31 and they get up to about 35-38 and seem to work well in that zone.
The whole purpose of Nitrogen is that it doesn't expand or contract like regular air due to heat. So you fill them up a given temp and theoretically, it should stay at that temp, heat regardless. So if you were to fill your track tires with Nitrogen, would you fill them at the HOT temp from the start (35-38)? Or the cold temp (30-32)? I am told, at most they only go up or down a 1lb in the most extreme conditions.
Just looking to see what people experience in the real world.
Now the tricky part...R compounds like Hoosier or 710's have cold and hot recommended pressures. I usually start cold around 30-31 and they get up to about 35-38 and seem to work well in that zone.
The whole purpose of Nitrogen is that it doesn't expand or contract like regular air due to heat. So you fill them up a given temp and theoretically, it should stay at that temp, heat regardless. So if you were to fill your track tires with Nitrogen, would you fill them at the HOT temp from the start (35-38)? Or the cold temp (30-32)? I am told, at most they only go up or down a 1lb in the most extreme conditions.
Just looking to see what people experience in the real world.
11-08-2007, 02:29 PM
#2
Former Vendor
You should start them about 2 maybe 3 pounds under your hot pressure. Then double check them cold vs hot. We have seen a couple pound change cold vs hot.
Randy
Randy
11-08-2007, 02:34 PM
#3
Melting Slicks
The whole purpose of Nitrogen is that it doesn't expand or contract like regular air due to heat. So you fill them up a given temp and theoretically, it should stay at that temp, heat regardless. So if you were to fill your track tires with Nitrogen, would you fill them at the HOT temp from the start (35-38)? Or the cold temp (30-32)? I am told, at most they only go up or down a 1lb in the most extreme conditions.
PV=NRT
P=pressure
V=volume
N=amount of gas (in moles)
R=Constant
T=Temp
So, the pressure will still rise with temp (but without the water and other stuff that is in the air, not as much).
11-08-2007, 03:08 PM
#5
Le Mans Master
Thread Starter
Also, it great that I can get free Nitrogen, but when I need to add some air at the track, I won't be carrying extra Nitrogen, so would mixing with air be an issue?
11-08-2007, 03:22 PM
#6
Drifting
You would only be adding a small volume of air, and won't change things. Realize, even when you fill with Nitrogen, there is still a lot of air in the tire. In other words, they don't vacuum the tire before filling with nitrogen.
11-08-2007, 03:26 PM
#7
Le Mans Master
Another issue is evacuating all of the normal air (water content) out of the tire. Unless you draw a vacuum on the mounted tire and maintain it until nitrogen is introduced, there will still be some normal air (water content) in the tire.
I'd expect the normal air mixed with the nitrogen would decrease the benefit of the nitrogen.
I'd expect the normal air mixed with the nitrogen would decrease the benefit of the nitrogen.
11-08-2007, 04:46 PM
#9
Instructor
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Nitrogen in tires
Air is 79% Nitrogen! If there is any difference, it would be in moisture content. Try putting a dryer on the air you use for inflating.
The other advantage is not having the 19-20 % Oxygen in the tire? I suppose that this will help with any oxidation inside the tire at high temperatures!
The other advantage is not having the 19-20 % Oxygen in the tire? I suppose that this will help with any oxidation inside the tire at high temperatures!
11-08-2007, 05:10 PM
#10
Le Mans Master<br><img src="/forums/images/ranks/5k-6k.gif" border="0">
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St. Jude Donor '08-'09
Another issue is evacuating all of the normal air (water content) out of the tire. Unless you draw a vacuum on the mounted tire and maintain it until nitrogen is introduced, there will still be some normal air (water content) in the tire.
I'd expect the normal air mixed with the nitrogen would decrease the benefit of the nitrogen.
I'd expect the normal air mixed with the nitrogen would decrease the benefit of the nitrogen.
http://forums.corvetteforum.com/show....php?t=1849184
11-08-2007, 05:13 PM
#12
Former Vendor
Randy
11-08-2007, 05:15 PM
#13
Former Vendor
11-08-2007, 05:52 PM
#14
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You can buy a pressure regulator and hose setup for your garage at home and fill your own tires with N2 at will. You can get the N2 from a gas supplier and as Randy has said, fill up your track air tank for adjustments.
11-08-2007, 06:08 PM
#15
Former Vendor
I was thinking a small air tank that you can buy at the auto parts store.
Randy
11-08-2007, 06:31 PM
#17
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
The main advantage is to remove as much moisture content from inside the tires as you can. The change in water vapor can affect pressures on the cars, and if you are keeping track of your pressures at different tracks under different conditions this can better give you an idea of what to set the tires for given a certain air and track temp.
What you are looking for is consistency in your testing methods and measurements.
11-08-2007, 06:57 PM
#18
Le Mans Master
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I use it as much for convienence as much as the technical advantages. I had to buy a tank and regulator anyway for the Penske shocks, so I put it on a Wal-mart dolly and now I use it for everything. It is only about $20 to fill it and it lasts me about 6 months. It is easy to take to the track, and I find that even when my wife's Caddy or my tractor needs air in the tires, it is easier to take the tank to the car or tractor then dragging the long hose from the compresor.
11-08-2007, 09:42 PM
#20
Team Owner
