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

 

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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