Mailing List flyrotary@lancaironline.net Message #67249
From: Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net>
Subject: EC2/3 Tuning
Date: Tue, 24 May 2022 13:48:23 +0800
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Hi people.

I have a question about tuning the EC2/3’s and particularly Mode #2 'Dynamic Range Adjust'

I have left Mode #2 at the default setting and no problem tuning. However here is the thing:

I have some friends that are very experienced pilots (unlike myself) and on flying the Glasair they have asked if it is possible to adjust the mixture control so that at:
1. Full CW rotation sets full rich which in my experience and understanding is ~0.85 lambda or 12.5:1 AFM, and
2. Full CCW rotation sets full lean, again I’m thinking ~1.07 lambda or 15.8:1

It's really point 1. I’m interested in.

What my friends are asking is that they are confident that behind their Lycomings in an emergency they just push that Red knob all the way in and get on with flying the aeroplane.
In my setup, if I turn the Mixture Knob full rich it would probably make the fan stop. My Mixture Knob set at 12 O’clock is about Stoichiometric and best power is less than 2 O’clock.

For them, this is a significant safety issue.

But I’m struggling with the description in the Programming Guide.

Can anyone confirm that adjusting Mode #2 'Dynamic Range Adjust’ will change, well, the 'Dynamic Range' of both the mixture correction table and the Mixture Knob.

Could I reduce the Dynamic Range parameter so that once the MCT is set correctly I will then have a situation where quickly turning the Mixture Control FULL CW the Engine will be at Full Rich.

If it does what I’m thinking/hoping, the adjustments required in the MCT will be larger.
Currently my MCT adjustment amounts are positive and negative about half of the available range (-70 & +60 decimal)
So by reducing the Dynamic Range by approx. half, will I then need the full +- 127 decimal range of the MCT and will the Mixture Knob then be approx half as sensitive?

I didn’t want to mess up my tune before asking if someone can confirm how Mode #2 works.

Thanks

Steve Izett
Renesis 4 port RD1-C EC2 EM3





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