Wide Range O2

[Matt Beaubien]

Brock,

> I have a little sideline item that is on-topic with your above mentioned
> idea.  On the $8000 (wide-range) meters made by ECM (Engine Control and
> Monitoring), they have a "dummy 02 sensor" output on the back of the box
> that is able to be connected to a factory controller expecting a
> "switchpoint" type signal.  Unfortunately, their algorithm was less than
> genius in that it basically "switched" between 0 and 1 volt.  In other
> words, it was binary.  As you might guess, this did a lame job of
> simulating a sweeping signal from a real switching O2 sensor.
> 
> As another note, we often logged data with this meter and found that data
> points that were a tenth of a second apart resulted in an amazing amount of
> resolution.  For instance, if you recorded an event of "whacking open" the
> throttle, you could see a quite lean period of about .2 seconds with a
> factory ECM that represented the "lag time" between the fuel metering
> system and the airflow surge...  We used this momentarily "high" AFR to
> mark the beginning of the dyno run.

Brock, I've also had some experience with the ECM unit. It does have very
good response when set to fast response (.02 sec I believe). Does it use
the NTK sensor? I should check it out...

I used it when trying to calibrate a LSM-11 sensor, logging the outputs of
both. The LSM-11 had the same reaction time as the ECM unit, as far as my
cheap data acquisition could measure. The data logging feature of the ECM
unit could come in very handy for tuning vehicles.

My two bits.

Matt Beaubien
mbeaubie at gpu.srv.ualberta.ca