[s-cars] Nitrogen in tires?

[Charlie Smith]

Earlier, ccohen5 wrote:
>
> How does one get the stuff into the tires without mixing it with air.  Or is
> it acceptable to have a N concentration but not pure N except for those F1
> folks who probably fill their tires in a vacuum chamber??

Use of nitrogen in tires is a common practice with racers, because
tire pressure is critical for best handling.  They carry a pressure
bottle, similar to an oxygen tank used with welders.  To set up
something like this, you'll need a high pressure regulator just
like on a welding tank.

After installation, inflate the tire and deflate it once,
then inflate it again.  That gets rid of most of the air.
With a race tire, the sidewalls are very thin and flexible,
so one can 'squish' the tire and get most of the air-nitrogen
out of it before the second filling.  Since race tires leak
like crazy, subsequent fillings will have even less air in
them.  Figure, this will greatly reduce the pressure change with
temperature change, and that's what's important.

Also figure - race tires are more sensitive to pressure being
exactly spot-on.  Plus, the benefits of nitrogen allow the pressure
to be right even on the first lap before the tires are fully heated up.

    - Charlie