From: Mike Fontenot <mikef@apexconsultingservices.com>
Subject: [FlyRotary] Initial Tuning - Today's Cornfusing Efforts
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Date: Sunday, May 10, 2009, 10:43 PM

Tracy and all,

I saw your note about Mode 9 auto-tune, I will re-read the manual.

Today I was able to tie her down and run the engine up to the MAP value to 22. It was right around 4700 RPM. Let me say that things were just a bit overwhelming, while sitting in the cockpit, engine roaring behind me, and the EM2 doing what I thought was 'odd' stuff. Anyway, feedback and advice is appreciated. I'm not sure I really made much progress today. Also, it looks like my alternator is not turning on. I was expecting to see increased voltage at these higher RPMs (I've never taken the engine to this RPM before), but that did not happen. Happily the batteries ran the system for a good 45 minutes, but I could see the voltage dropping, to a low point of around 11.8 volts at the end of the day. That is a problem I had not anticipated, all my electrical checks to this point were good. Hmmmm.

I did use the EM2 to view the Injector setting before starting to change Mode 3, it was 230.

I did have printed documents for tuning each mode I was planning on trying today. But with the wild swings of the Mixture indicator it left me confused. I have a feeling others might have experienced something like this when first trying to tune the EC2, it was frustrating.

STEP 1 - Tune Mode 3 - I started trying to tune Mode 3. I had no problems getting the MAP up to 22, I was able to use the Mixture Knob to keep the engine running smoothly. And clearly, if I leaned the mixture the MAP/RPM decreased. While increasing Mixture did the opposite. I could see changes in the EM2 Mixture Indicator (more shortly).

I started trying to balance the Mode 3 values by using the Program Knob/Store, Mixture Knob, and watching the EM2 mixture indicator.
First, on the EM2 (normal view) I could see the Mixture Indicator but to the right of it were four more bars. What the heck are those?? I don't see anything in the manuals mentioning these other four bars. And it even seems like they came and went. Weird.

While at MAP 22, if I increased the Mixture Knob just slightly past 1200, like to 1230, the Mixture Indicator would jump to 2 bars.
Here is an example of what I would do, and what would happen:

MAP at 22, Mixture Knob at 0200, engine running smoothly. I would put the Program Knob at 0300 and press the Store button. Doing this the EM2 Mixture Indicator would jump to 2 bars right away. Engine would continue to run.  Then if I reduced the Mixture Knob to 1200 the EM2 Mixture Indicator would drop  to about 30%. The engine would clearly drop in RPM and MAP as well. Moving Mixture Knob clockwise would speed it up and increase output. Overall the engine ran smoothly at this RPM, I'm just not sure if I am at 1 bar mixture.

This big movement would happen if I was using the Program Knob to increase or decrease the Injector setting. So these big jumps in the Mixture Indicator made it difficult for me to narrow in on values. Same thing for moving Mixture in the other direction.

Any ideas what could be causing such large changes for tiny adjustment? I did the best I could in getting the Mixture Indicator at 1 bar, and I looked in EM2 Table View for the Injector Flow rate, it read 153.

So as I reduced the throttle down to the low end RPM the engine ran rough, and the only way to keep it somewhat smooth was to move the Mixture Knob to 0500. I felt like the engine would quit if I throttled very low. Surgy and sort of rough.

Step 2 - Tune Mode 2 - Again the twitchy Mixture Indicator made it difficult for me to make precise changes. The engine was definitely running rougher now at this low RPM range. And the Mode 2 instructions are confusing to me especially this first time out, sort of a reverse logic (If you make large mixture rich movements then decrease injector dynamic range). I know it sounds logical sitting here reading it on the internets, it was confusing in the cockpit.

Since I was holding the Mixture Knob to 0500 (rich) I decreased the Mode 2 value. Again, the Mixture Indicator would jump down quickly. Engine still ran rough. I really felt like I was all over the place in this Mode 2. So I don't feel confident in the settings I have made so far.

I shut the engine down, and restarted a couple of times, just to convince myself it would start again after these adjustment. It did, but ran really rough and weak at lowest MAP/RPM. Just a slight increase in the RPM seemed to quickly smooth things out. I am really sort of wondering if the Mode 3 Injector flow got adjusted too low.

That was it, I was fried. Overall running time was about 50 minutes. Feedback, advice and suggestions are greatly appreciated.

Thanks,

--
Mike

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Mike Fontenot
Apex Consulting & Services LLC
Lakewood, Colorado
303 / 731-6645
mikef AT apexconsultingservices DOT com
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