Mike_964

I'm going to get my new tyres installed and was thinking about filling them with nitrogen. Nitrogen doesn't expand when warm so you get the benefit of a correct tyre pressure all the time.
But normally I run with 2.5 bar both front and rear as cold pressure, but with nitrogen it of course has to be higher, so how much pressure should I go for?
2.8 or?
I use the car both for tracking and on the road. The tyres are Toyo Proxes T1R.

springer3

What makes you think nitrogen does not expand? PV=nRT is the gas law equation relating pressure, volume, and temperature. Air is already 78% nitrogen. Pure nitrogen is better because you exclude oxygen and water vapor from the tires, but tires rot from the outside where you have little control of the atmosphere.

Geoffrey

Unless you have the equipment to purge the tires completely you won't see a difference with using a Nitrogen air source rather than a standard air source.

ilko

Remember this guy?



It was filled with nitrogen. You might want to try helium instead, but as others have pointed out it won't make a difference as far as performance is concerned.

Superunknown

Won't using helium make the car lighter though...

Geoffrey

Ummm, I think the Hindenburg was filled with Hydrogen,

ilko

You're right! I studied chemistry in another country so I still have a hard time translating the elements in English

Larry Herman

Geoffrey, you're being uncharacteristically diplomatic here.

Fred's 964

I believe the reason Nitrogen is used in aircraft tires is the low moisture content. At 40,000 feet, any air suspended moisture in the tires would condense, freeze and could create an out of balance condition on landing. Dry air would probably serve the same purpose, but dry nitrogen in 1500 psi cylinders is a convenient dry air. Large aircraft tires hold a lot of air at about 250 psi, that would be a lot of moisture if the air was not dry. For our cars, there is probably no benefit. Some say the pressure stays more consistent, this may also have to do with moisture content of an expanding gas at higher temps. At our tire temps, also probably not a negligible difference. Get a beer and some popcorn and go here for more info:
http://www.eng-tips.com/viewthread.c...=120996&page=1

flatsics

This is a common thing I hear at the track.People use Nitrogen and do not see a change from using plain old air. So here is a question--Why does everybody worry so much about using nitrogen in their remote resevoir shocks?

Larry Herman

Moisture.

Mike_964

I guess I almost fell for an old sales trick.... Of course Nitrogen expands when heated.
So I'll just buy for $40 worth of air instead ;-)
Yes. they where really trying to rip me of!

38D

Exactly.

flatsics

Quote:
Originally Posted by Larry Herman
Moisture.



Exactly.
__________________
- Colin
GTC Motorsports


Ok--I understand its for moisture reasons. I guess what I am unclear about is if this really works-in the way we use it.
Is the Nitrogen you get when your tank is filled "dry"?
Is the reason you dont see the benefit of the Nitrogen when we use in tires because they are contaminated with "wet" air?
How do you purge your tires of the "wet" air?

I am not trying to be a pain, I am going to start usin DA shock this year. Since I am going to have a Nitrogen tank set-up, I am just trying to figure out how to properly use it for tires.

LA964RS

If there is any moisture in the tire...@ 212ºF you will get a sudden increase in tire pressure as the moisture turns to steam. You will see now at IRl and Champ Car events Bridgestone/Firestone using a system that takes moisture out of the air they put in the tires during mounting...essentially an air dryer. Many teams are just using it that way instead of releasing the air and refilling w/Nitrogen.