Thanks for the kind
words about the EFISM, Jeff. I think most folks will find that being
able to graphically see their fuel MAP/MCT makes it much easier to understand
what your engine is doing and how well your MAP is adjusted – the only
two units offered that are capable of doing this (that I am aware
of)
Is Tracy’s RWL excellent
EM2/3 system and my EFISM. Either one will provide this capability.
You can certainly
tune and fly safely without either of these units to monitor/adjust your MAP –
I did it for years. However, I never could eliminate my staging bog (for
example) until I watch the air/fuel ratio indicator and the fuel MAP as the
engine operating point approached the staging point. For whatever the
reason, my A/F ratio would take a nose dive toward the lean side just
before staging – causing a temporary (but annoying) hesitation or bog.
Using the graphical display I began increasing the richness of each bin as the
A/F indicated lean and advance bin by bin making this adjustment until
after increasing 4-6 bins just before the staging point, my staging bog has
completely disappeared.
It is also difficult
(at least for me) to try to tune the EC2 by advancing the manifold pressure ½”
Hg at a time to activate each bin. I also found (using the EFISM),
that when I adjusted the value of the bin my engine was operating on – that
change (rich or lean) invariably cause the engine to change operating
conditions – just enough so that it would shift to the adjacent bin or two –
so I was no longer tuning the same bin as a moment before. I know some
can do it by hear – Tracy for example – but, for me visual was
much easier to do.
In any case whether
Tracy’s EM2/3
or my EFISM – I think most will find a graphical representation easier to work
with.
Ed
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Jeff Whaley
Sent: Wednesday, July 29, 2009 9:05
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] EC2 and Ed's EFISM -
a great combination
The following is
an excerpt from a Mike Wills post several months
ago:
“Anyone trying to tune up
Tracy's EC2
without either having an EM2/3 or Ed Anderson's EFISM, you're wasting your
time. I spent the better part of a year tweaking the MAP table and thought I
had it pretty well done. On my first flight I spent a fair amount of time
fiddling with mixtures and had a couple of rough running spots. I installed
Ed's EFISM and spent 2 days tweaking. In the process I got the engine running
smoother than it ever has and now have it is idling nicely at 1350 RPM. That’s
300 RPM lower than I was ever able to get it previously. In my opinion you
really HAVE to have some sort of indication of what is loaded in the MAP
table to effectively tune it.”
I whole-heartedly
agree!! I installed ED’s EFISM last night and was anxious to see my MCT –
let’s just say it was a mess. There were a few points, mostly around the
staging area, where I could see that some tuning had taken place; however,
there were several locations with wild swings from one bin to the next. These
wild variations appeared in the middle of the high rpm band where the engine
has spent very little time, as I’m usually near idle or WOT – but man it sure
is nice to actually see what’s going on.
Jeff
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