Sensor Questions?

[Zublin, Bryan (SD-MS)]

Clint writes:

>Quick question: what exactly is going to cause this "sudden increase in the
>amount of required air" that is going to draw a vacuum?

I don't know all of the physics behind it, but it is related to the velocity 
and inertia of the air, length of intake track, etc.  The previous post 
about "acceleration enrichment strategies that are a function of throttle 
transients" was correct and is how the computer compensates for this 
condition.

>Just remember that a MAF system also has to be calibrated to the engine it 
is
>on.  The MAF give out a voltage (or frequency) depending on how much air is
>going through it.  It does not tell you "currently, there is x Kg/sec 
flowing
>through me".

Excuse me?  That's exactly what the MAF *does* tell you:  mass air flow 
(kg/hr) flowing through the meter and into the engine.  That's the beauty of 
the MAF.  Pressure, temperature, and density variations do not have a 
(large) effect on the accuracy.

Bryan Zublin
bzublin at gi.com