While trouble shooting Al Gietzen's EC2 engine controller problems, he
mentioned that he was seeing relatively large mixture changes when the
alternator was switched off and the battery voltage went low. The
mixture goes leaner with lower battery voltage because the injectors take
longer to open. It was well within the range of the manual mixture
control to correct but it got me to thinking about adding battery
voltage compensation to the EC2. This has been done and all
controllers shipped after 9-20-06 now incorporate this feature. Not a
freebie, but if anyone wants this incorporated into an earlier EC2 it can be
retrofitted.
The other update is a rev limiter. It was easy to do so I went ahead
and added it. I haven't seen this as a priority because in our application if
you make use of it, it means that you need to be more concerned about the
pilot's health than the engine's (the prop has fallen off the airplane).
The default rev limit is 8000 rpm. If you want something
different, specify when ordering. (Also retrofittable)
EC2 / EM2 Installation Note.
This only applies to EC2 engine controller installations combined with
early two-part EM2 engine monitors in canard aircraft where both units are
installed near the engine and have long wiring harnesses connecting them to
the EC2 front panel and EM2 display (a rare combination that may be unique to
Al's airplane). Have been working with Al for some time searching
for the cause of random MAP table and other EC2 parameter corruption. I
am now almost certain that the cause is noise coupling from the EM2 display
harness into the EC2 control panel harness. The two harnesses were
laced together in Al's installation. He is in the process of
separating them now (sympathies to Al, no picnic). Needless to say
at this point, never run these two harnesses together and separate them
as far as practical. I think Al will have about 4 inches between
them when separated.
Tracy Crook, RWS