Still more Questions ....

[atsakiri at ford.com]

> I have more question on MAF sensors
> 
> The MAF on OEM's is always plaed very fare from the throtle body 
> by doing this we have to
> reaslise that we have the intake + the air hose that act as a 
> resevoir after the metered 
> air has passed the MAF, would it not be better placed as close 
> as posible to the intake 
> ???

The "reservoir" problem is definitely a disadvantage of placing a
mass air flow sensor considerably upstream of the intake valves.
However, there are advantages of this placement too.

The sensing element is usually small compared to the full diameter
of the sensor.  A relationship between the local flow and the
bulk flow is necessary.  The more well-developed the flow is, the 
more accurate and robust such a relationship will be.

Also, the flow is not steady, but pulsating.  The flow rate varies
due to the cyclic nature of the engine's induction.  Placing a
sensor upstream helps to isolate it from the pulsations.


Anthony Tsakiris

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The opinions expressed are my own and not necessarily those of my employer.