More silly ideas

[Ludis Langens]

Bruce Plecan wrote:
> 
> What if someone wanted to use a straight full time baro correction (for a
> MAP system)?.   Could it be done as simply as using a 1bar MAP referenced to
> atmosphere, and then the output from that one used as the reference voltage
> to a second MAP that is referenced to the engine vacuum.
>    Then carrying this further how about as a correction for 2+3 bar MAPs?.
> All of the above would be require deleting the baro calc from the prom, and
> recalibrating the Tables, that are VE related.

I'm not sure quite what you are trying to do.  I assume you want to get
rid of the inferred BAP calculation and to substitute a real BAP sensor.
 A MAP sensor measuring open air, hooked to another ECM analog input,
and with some code changes would work.

If that's not what you want, keep in mind that the ECM computes and uses
various pressure values.  It has absolute pressure, baro pressure, and
gauge pressure (aka manifold vaccuum).  For example, one ECM has an
intake VE table indexed by MAP, and an exhaust VE (aka backpressure)
table indexed by BAP.  The same ECM also has lots of tables indexed by vacuum.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/