From: "Finn Lassen finn.lassen@verizon.net" <flyrotary@lancaironline.net>
Received-SPF: pass
 receiver=logan.com; client-ip=66.163.191.206; envelope-from=finn.lassen@verizon.net
Subject: Re: [FlyRotary] Re: EC2/3 Mixture Correction Table
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
References: <list-684598@logan.com>
Message-ID: <5ed0d6eb-6f60-a20a-f1c9-06c4fcd2acdf@verizon.net>
Date: Thu, 17 Feb 2022 19:36:12 -0500
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <list-684598@logan.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Content-Length: 4981

I'm using the O2 signal from the EC3. Not sure if the EC2 has that 
option, but if it has auto tune I'd think so.
When using the EC3 O2 signal, the EM3 looks at EC3 ENGINFO WIDEBAND bit, 
so it's automatic.

 From the EM3 manual:
EM3 OPTION SELECTION VARIABLE  DEFINITIONS

CHANNEL  9,         O2 SENSOR (MIX)
OPTIONS AFFECTED   -      O2  Sensor Installed (Parameter 2)
              Air Data option enable    (parameter 3)
              EC3 O2 Sensor select    (Parameter 4)

PARAMETER  2 (sensor offset)     Set to 1 if O2 sensor  (connected to 
EM3)   0 if not.

PARAMETER  3 (low limit alarm)   Set to 1 if Air Data option installed,  
0 if not.

PARAMETER  4 (high limit alarm)   Set to 1  to use the O2 Sensor on the 
EC3 instead of one connected to the EM3.  Set to 0 if using the EM3 O2 
sensor.
also
CHANNEL 14           MISCELLANEOUS
OPTIONS AFFECTED       BSFC of engine at 14.7 A/F mixture            (P. 0)
             1%  of maximum engine power                   (P. 1)
             Fuel Pressure Sensor type                       (P. 2)
             Mixture Monitor sensitivity                   (P. 3)

PARAMETER  0 (sensor offset)    Brake Fuel Specific Consumption in 
Lb/HP/Hr.  .55 is typical Rotary engine value at a median mixture.  If 
you think your engine is more efficient than this, reduce this value. It 
will affect the displayed  HP and percentage of engine power on the 
EM3.  The very best engines have about .47 BSFC.

PARAMETER  1 (zero offset)   1% of max engine power.  For example,  if 
your engine makes 250 HP max, set this to 2.50.

PARAMETER 2 (sensor offset)   Fuel Pressure Sensor used.  Set to 0 if 
using Stewart Warner 33 - 240 ohm sender.  Set to 1 if using VDO 10 - 
180 ohm sender.

PARAMETER 3 (mixture monitor sensitivity)  Lowering this value makes the 
mixture monitor more sensitive.   Used to compensate for differences in 
O2 sensor sensitivity.   Adjust so that stoichiometric mixture (14.7 : 
1  A/F ratio) reads 1/2 scale on bargraph.

Because the wideband O2 signal is inverted from the narrowband, you'd 
probably need to insert an inverting opamp if using the O2/Mixture input 
on the EM3.

Finn

On 2/17/2022 4:49 PM, Stephen Izett stephen.izett@gmail.com wrote:
> Thanks Finn for the feedback.
>
> Yes, I think even with the 8 table configuration I see areas in the map where its hard to get it right.
> I’m installing a better camera mount today so I can record the EM3 MCT display and Wideband on the Dynon so I can do some more post flight tuning of those areas hard to pickup in flight.
> I wish I could adjust the code of the EM3 and change the O2 to Wideband instead of narrow.
>
> Cheers
>
> Steve
>
>
>
>
>
>
>
>
>
>> On 18 Feb 2022, at 12:10 am, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:
>>
>> You're still way ahead of me.
>>
>> I thought I had auto-tuned all tables. Yet found it going lean when added throttle to climb around 4,200+ RPM. Disconcerting. Could be change in AOA influences intake. Need to fly and tune more. Only 33 hours in the air so far. And yet now have to do annual condition inspection :(
>> About 3 shots of prime in 80F + temps. More in colder temps.
>>
>> Finn
>>
>>
>> On 2/17/2022 3:42 AM, Stephen Izett stephen.izett@gmail.com wrote:
>>> Hi Guys
>>>
>>> I’m using an EC2 with an 8 table MCT
>>>
>>> Ive never adjusted the early table entries that only get used during those initial moments at startup.
>>> Our Renesis 4 port, at startup initially runs just below 1500 rpm and over the next ~ 30 seconds warms and then idles at our desired 1800 rpm. The RD1C can make some noise if we lower that idle.
>>>
>>> As its pretty tricky to get mixture readings as the engine first fires up, I’m wondering if anyone has experimented with playing with those early addresses of the MCT and found this has made for a sweeter startup.
>>>
>>> Also on startup I have settled into giving 4-5 priming shots when the engine is cold. And only a few when warm. It takes double or triple the revolutions to start when warmed up.
>>>
>>> Our OAT is generally somewhere between 60-85F
>>>
>>> I’m wondering what others with similar warmer climbs have found is the best technique.
>>>
>>> Thanks
>>>
>>> Steve Izett
>>> Perth Western Australia
>>>
>>>
>>>
>>>
>>>
>>> --
>>> Homepage:  http://www.flyrotary.com/
>>> Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>>
>>
>> ---
>> This email has been checked for viruses by Avast antivirus software.
>> https://www.avast.com/antivirus
>>
>>
>> --
>> Homepage:  http://www.flyrotary.com/
>> Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html
>