MAP system

[Jim Staff]

  The question all you great theorists are here to answer. In Map based system I
measure pressure, however I need to put the unit on the outside of a pipe not to
disturb air flow. However this placement gives me only the pressure exerted on 
the walls of the pipe and not the pressure in the tube.




                            _______
                            |     |
                            |     | <-Sensor
                            |     |
----------------------------+-----+-------------------------------------------
            ^
            |            <---------------------  Desired air stream
        Measured Pressure    
------------------------------------------------------------------------------


  What is the formula to correct for this problem. My physics teachers couldn't 
tell me what it was but they knew that in principle it wasn't an impossible 
problem. In fact some great scientists based thier lives work on this So I know 
it can be done, however I bet it uses calculus and evil variables that I can't 
control. So be kind..... Also every MAP sensor I've ever seen is used like this.
I checked it out in a ford tempo GX and an Olsmobile firenza..

   My new system for an injector is much better, I calculate virtual gearing and
I track the mpg.. I'm good-- well decent..