nitrogen filled tires good idea or.........
Originally Posted by honda-guy
to run a nitrogen setup effectively, you need to have two valve stem. you need to bleed the air inside the tire while you fill it up with nitrogen.
Honda-Guy is totally right on this one!
I work as a machinist at a job shop. A local engineer had us build a nitrogen fill system, that he was selling to Nascar teams. It had a vac pump to pull all the air out of the tire, run the nitrogen through a dryer, and into the tire. Then vac it out again, fill, vac fill, ect.. untill they were sure it was all pure dry nitrogen in the tire.
ummm, isn't the R value called the gas "constant" and thus should be treated like one?
PV = nRT... now i realize that yes, you are right that assuming different gases do expand at different rates (and thus have different R values), but even at 20atm nitrogen is still 8.314J/mol*K and pure O2 is like 8.02J/mol*k for a difference of only 3.5% all the gases we can assume would be in the tire are going to be within 1% of the same R value at any pressures you would fill your tire to (i.e. less then 5atm).
now it has been a while sense i have had a chemistry class, and if i am wrong please correct me.
PV = nRT... now i realize that yes, you are right that assuming different gases do expand at different rates (and thus have different R values), but even at 20atm nitrogen is still 8.314J/mol*K and pure O2 is like 8.02J/mol*k for a difference of only 3.5% all the gases we can assume would be in the tire are going to be within 1% of the same R value at any pressures you would fill your tire to (i.e. less then 5atm).
now it has been a while sense i have had a chemistry class, and if i am wrong please correct me.
yes, I deleted my post because it was probably confusing. As already said, air is mostly nitrogen and the R values are essentially the same so the air vs nitrogen is not what is causing the pressure stability.
yes, R is a constant
edit: the key is that the equal *volumes* of all gases do expand the same with same change in temp. I was thinking too much.
yes, R is a constant
edit: the key is that the equal *volumes* of all gases do expand the same with same change in temp. I was thinking too much.
Last edited by Steve_P; Dec 19, 2005 at 07:35 AM.
Originally Posted by stpracer
Over on the Speedtv boards under the F1 discussion they had concluded that nitrogen does nothing that dry air can't. They also claimed that F1 teams did not use nitrogen in their tires.
But I was talking to my son who is an airline mechanic and he tells me that the FAA specs nitrogen in airplane/jet tires for exactly the reasons that everyone else has said. It does not expand during the heating and cooling cycles that a jet goes through. Also it does not lose pressure as regular air seems to.
But I was talking to my son who is an airline mechanic and he tells me that the FAA specs nitrogen in airplane/jet tires for exactly the reasons that everyone else has said. It does not expand during the heating and cooling cycles that a jet goes through. Also it does not lose pressure as regular air seems to.
Evolving Member
Joined: Jan 2005
Posts: 294
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From: Kent, WA
Originally Posted by stpracer
Over on the Speedtv boards under the F1 discussion they had concluded that nitrogen does nothing that dry air can't. They also claimed that F1 teams did not use nitrogen in their tires.
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