How much helium could you put into car tires? Enough to make a difference?

[Sukhoi]

Yeah, ideal gasses are directly related to T.

 

[geno]

Originally posted by: Jhill
I've always wanted to fill a football with enough helium to make it really light. Then punt it 200 yards away while my friends worship me.

No one will ever worship a Punter/Kicker, start practicing your Hail Mary pass 😛

 

[sharkeeper]

Fill them with acetylene! 😛

Cheers!

p.s. Water in tyres is actually quite funny. Don't put it in the fronts though, especially if they drive an SUV. The vehicle WILL flip over at highway speed!

Cheers!

 

[BrunoPuntzJones]

Or fill them gasoline. Will make a nice show at the next accident.

Would be quite amusing to fill your tank up at the gas station, then go around and fill up each tire.

 

[HomeBrewerDude]

Originally posted by: Feldenak

Originally posted by: Jhill
I've always wanted to fill a football with enough helium to make it really light. Then punt it 200 yards away while my friends worship me.

Heh, you mean like Jackie Sherrell accused Auburn of doing because the punter was averaging around 50 yards/punt? 🙂

hahah Jackie Sherrell... what a card! Although you do realize most people here were sh!tting their diapers when Sherrell was run out of College Station.?!?!

 

[thedarkwolf]

Just read an article on ways people use to cheat in Nascar. One guy use to fill his first set of tires with 100lbs of lead strips each. The cars have to weigh a specific amout so this way after he made the first pit stop his car would be 400lbs lighter than everybody else of coarse before the first pit stop his car handled like crap 🙂.

 

[Ronstang]

Originally posted by: yamahaXS

Originally posted by: Feldenak

Originally posted by: Jhill
I've always wanted to fill a football with enough helium to make it really light. Then punt it 200 yards away while my friends worship me.

Heh, you mean like Jackie Sherrell accused Auburn of doing because the punter was averaging around 50 yards/punt? 🙂

hahah Jackie Sherrell... what a card! Although you do realize most people here were sh!tting their diapers when Sherrell was run out of College Station.?!?!

Maybe so, but I was in college at A&M at the time and a friend of mine lived next door to Jackie. 😉

 

[PowerMacG5]

Originally posted by: thedarkwolf
Just read an article on ways people use to cheat in Nascar. One guy use to fill his first set of tires with 100lbs of lead strips each. The cars have to weigh a specific amout so this way after he made the first pit stop his car would be 400lbs lighter than everybody else of coarse before the first pit stop his car handled like crap 🙂.

That's no longer possible. The tires are pretty much regulated up until the second they are put on the car now.

 

[RossGr]

Originally posted by: Ronstang

Originally posted by: RossGr

Nitrogen cuts down on the PSI changes with tempeature

At the pressure and densities of gas in your tires, the ideal gas law:

PV=nRT

holds.

So Pressure (P) = nRT/V
n = the number of moles of particles present
R = Universal Gas constant= 8.3 J/mole K
T= Temperature
V = Volumn

No where do I see where it matters if you use pure N2 or air (80% N2)

Then you aren't looking hard enough because using N2 versus air makes a big difference on the racetrack where the tires see extreme temperatures.

Data?
If there is a pressure variation with temperature which is different between N2 and air it is not due to the ideal gas law, perhaps there is some chemical reaction with tires that selectively removes O2 from air, therefore with an increase in temp you could lose 20% of your air pressure. Pure N2 would not see this loss.

 

[Feldenak]

Originally posted by: yamahaXS

Originally posted by: Feldenak

Originally posted by: Jhill
I've always wanted to fill a football with enough helium to make it really light. Then punt it 200 yards away while my friends worship me.

Heh, you mean like Jackie Sherrell accused Auburn of doing because the punter was averaging around 50 yards/punt? 🙂

hahah Jackie Sherrell... what a card! Although you do realize most people here were sh!tting their diapers when Sherrell was run out of College Station.?!?!

Yikes, was it that long ago?

Edit: It has to be within the last 10 years because he made that accusation after I got to Auburn.

 

[Chaotic42]

Originally posted by: FoBoT
i am sure any Dense Gas will do

Just use lead gas. Of course, you'd have to keep your tires warm.

 

[silverpig]

Originally posted by: RossGr

Originally posted by: Ronstang

Originally posted by: RossGr

Nitrogen cuts down on the PSI changes with tempeature

At the pressure and densities of gas in your tires, the ideal gas law:

PV=nRT

holds.

So Pressure (P) = nRT/V
n = the number of moles of particles present
R = Universal Gas constant= 8.3 J/mole K
T= Temperature
V = Volumn

No where do I see where it matters if you use pure N2 or air (80% N2)

Then you aren't looking hard enough because using N2 versus air makes a big difference on the racetrack where the tires see extreme temperatures.

Data?
If there is a pressure variation with temperature which is different between N2 and air it is not due to the ideal gas law, perhaps there is some chemical reaction with tires that selectively removes O2 from air, therefore with an increase in temp you could lose 20% of your air pressure. Pure N2 would not see this loss.

I believe it has something to do with the equilibrium reaction of the gases...

N2 + 02 <=> N2O2

or is it 2NO? or N20? Or N02?

There is definitely an equilibrium reaction going on there though which is greatly affected by pressure and temperature.

 

[silverpig]

Ahhh, and then there's the 3/2 O2 <=> O3 reaction...

 

[Sukhoi]

We'd be damned near dead if that N2 + O2 -> whatever reaction went on very often. 😉

 

[Sukhoi]

What temperature ranges are we talking about? I can get the specific volumes for air and nitrogen this afternoon when I have time.

 

[AbsolutDealage]

Originally posted by: FoBoT

Sulfur hexafluoride

I was actually about to suggest this. It is the "heaviest" gas at STP, IIRC.

 

[StageLeft]

I fill mine with cheetah urine and they go faster.

 

[Demon-Xanth]

A lot of professional race teams use nitrogen because it's not as temperature dependant, is benign, and is easy to get.

 

[silverpig]

Originally posted by: Sukhoi
We'd be damned near dead if that N2 + O2 -> whatever reaction went on very often. 😉

It happens all the time, but it's an equilibrium reaction IIRC favouring pressure and temperature.