programming for a MAF based system

[Sean Olson]

> For a MAF system you want MAF, TPS, ACT, BAP, ECT, ISV, and RPM.
> Here's the reason:
>
> You want to reference MAF to RPM to infer VE.  Once you know VE,
> you can key in a table, just like MAP does.  The other reason is
> because you can make an even simpler inference:  Have a global
> that defines your lb/hr per HP.  With the MAF vs RPM you can calulate
> realtime HP and use that to simply find your base fuel pulswidth.


What is the advantage of inferring VE as opposed to using the MAF reading
itself to calculate the base pulsewidth?  It seems like finding VE would
add extra calculations and use more ROM for the MAF/RPM to VE and VE to
pulsewidth mappings.


> This makes for very simple integer math with table lookups if you
> want.
>
> Then add the O2 sensor to fine tune the mixture.
>
> The other sensors I'd use are BAP (baro), constantly to adjust for
> altitude, ACT for additional spark advance and air density, and
> ECT for input to lean/richen the mixture so as to obtain the desired
> engine temp. The BAP is important especially on turbo cars, because
> turbos were intended for altitude compensators.


Would the BAP be needed on a naturally aspirated engine?  The BAP is used
to compensate for air density (higher alititude air is less dense).
Doesn't the MAF take this into account?  Air that is more dense would cool
the film/wires at a different (higher) rate than would air that is less
dense.  Or am I totally off base?


Sean




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