Does anybody know what units are in for air density in this formula
     if V is in feet per second. I'll settle for the metric units.

     I think it is in pounds per cubic inch which
     is .000046676 under standard conditions.


     Paul Lamar ...No rotor no motor.

  Paul,
The small p is density (rho). p = P/RT
Matt


Yes but what are the units? Pounds per cubic inch? Pounds per cubic foot?
etc. etc.


I suspect it is pounds per cubic inch if V is in feet per second.

Here is what I get if it is in pounds per cubic inch and V is in feet per second.
-

I added inches of water. If this is correct it illustrates why you
need a choke or primers and idle circuits in carbs. The venturi
pressure is not low enough to suck much fuel at low RPM.
Carbs and venturis are a major trade off with high power requirements.