tire pressure; was: toss the throttle body completely?

[frank j. bauer]

At 04:16 PM 1/31/01 -0500, Hue sez:
>off the car there is no contact patch and the CP is the relationship
>between pressure and weight.
>
>come on guys, this is not rocket science.

and then he sez:
>tire pressure (weight/area) = weight on tire (weight) / contact patch
>(area)

tire pressure = force/area
since air doesn't care much about gravity, it doesn't exert any special
force against the contact patch.
rather it exerts its force in a fairly equal distribution against the
container, which in this case is the inside of the tire combined with the
area between the rims.
that is the area we are talking about in this equation.

it is true that there is a force applied by the weight of the car against
the contact patches.
however, i don't believe the size of these patches can be determined simply
by a linear relationship between weight and air pressure.
perhaps in an ideal system.
there are a lot of factors such as materials and construction that affect
the elasticity of the tire, for example.
think bias ply vs radial construction.
or, say you filled the tire with an incompressible fluid to the same pressure.

i could be wrong, though...

frank