OK, I’ll chime in here.  After reading Bob Darrah’s post last week where he noticed a big improvement after separating the leads to his coils I gave it a try on my 20B.  It made a big difference, but was most noticeable in the lower rpm range.  I was only able to separate the wires down near the coils, and then only by a small amount, but it made a substantial improvement.  My question for Tracy is, can I leave the grounds and +14v wires bundled together and only separate the trigger leads, or do I need to separate all the wires?  Also, if I were to use 3 individual shielded wires and ground the shields, could I then bundle the trigger leads together with the rest of the coil wires?

 

On a side note, after separating the coil leads, it took a much leaner mixture to get it to run smooth.  Before, the best it would idle was about 1200rpm, now it will idle nicely at 900 rpm, not that I want to do that, but it shows that the improvement isn’t all in my head.

 

Mark S.

    

 

 

----- Original Message -----

From: Tracy Crook

To: Rotary motors in aircraft

Sent: Wednesday, October 04, 2006 9:31 AM

Subject: [FlyRotary] Re: Latest EC2 updates, Installation notes

 

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