X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm23.access.bullet.mail.mud.yahoo.com ([66.94.237.88] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with SMTP id 5195445 for flyrotary@lancaironline.net; Thu, 10 Nov 2011 21:37:48 -0500 Received-SPF: softfail receiver=logan.com; client-ip=66.94.237.88; envelope-from=echristley@nc.rr.com Received: from [66.94.237.198] by nm23.access.bullet.mail.mud.yahoo.com with NNFMP; 11 Nov 2011 02:37:12 -0000 Received: from [66.94.237.111] by tm9.access.bullet.mail.mud.yahoo.com with NNFMP; 11 Nov 2011 02:37:12 -0000 Received: from [127.0.0.1] by omp1016.access.mail.mud.yahoo.com with NNFMP; 11 Nov 2011 02:37:12 -0000 X-Yahoo-Newman-Id: 662879.89029.bm@omp1016.access.mail.mud.yahoo.com Received: (qmail 12906 invoked from network); 11 Nov 2011 02:37:12 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1320979032; bh=4lHlgIH2RlMJ0Lq6S4bUgbHrK+ihYsHWjQrKx+7nLf4=; h=X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Message-ID:Date:From:Reply-To:User-Agent:MIME-Version:To:Subject:References:In-Reply-To:Content-Type; b=ls6hefZxaMws9zPboOJd5L9nVL7eGsHsGbeoXu5XyQiLnl/M4SarB5lTiGNMBScsQu4QBybdVq8Y9mEX+XfX5nQKzrXpmoog12ROXZQCtLJW0MWF6NO+qlK0UU3sWMqKY0kLrL66LDZEe9XOtyHwyoZImC7qzPgQUWBdqvQlEz4= X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: y78ge.0VM1l9MVono00kt4t4H3AoJIwrQ4thoD8IxAAr_34 3DDEHg.ZzZEgyqwPhZFau0MgrjNNGQh1afIAz_OHkaIbajB2YZhU6ZVRjneE QajFaZIqy5p_Vj.199sCaNEZconPIbNIROWGQ4l3DxtpSiAzzTxCdeUP7SEy J7qfPAuCCVoaaX5.m92NoZp5RxfFRZZ_3.2sNdZ5Ys7hbTfrvRumJnHOXxic EvoZcVWDirZp5Vjj1jVTphhC9.0zdJ7H2v.cycdFitgNZu90_ajXm62e30Ff 5rsaOxl_xxRSRonDE.fMjsjyKMaDrgNEQmfPfR.0wPhZL.cJh1Wfyj9cIvzA BwKzW5HwJu.BJ7uJhotDiDq8R3dzdfprAshJmqjfvjWxdJ5gELNaSzXx1Em2 bNdQzuGZbggvB22MRsomMZytfjv6OxcfXorNyFM.2zktOJIUJ0HTwstDrVxV 8oRZUUL51fsxV44IePCwTQhWOpkBmhRcOlPJGfeGdBHrMpANlgS0- X-Yahoo-SMTP: 40RP3pGswBDvPav1a.I8eMv.KS8bdgWBnCloVoKaow-- Received: from [192.168.1.2] (echristley@71.70.227.94 with plain) by smtp110.sbc.mail.mud.yahoo.com with SMTP; 10 Nov 2011 18:37:12 -0800 PST Message-ID: <4EBC8A4B.2080106@nc.rr.com> Date: Thu, 10 Nov 2011 21:36:59 -0500 From: Ernest Christley Reply-To: echristley@att.net User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.23) Gecko/20110921 Lightning/1.0b2 Thunderbird/3.1.15 MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Any tuning suggestions? References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------030900000904050108050800" This is a multi-part message in MIME format. --------------030900000904050108050800 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit I think I have a tune file that will implement these recommendations. I especially liked the comment about the F/A following the PW, regardless of what the AFR gauge says. I was missing that, and thinking that I couldn't know what is going on when the gauge is finicky. It's only finicky at cold startup, but it is always good to remember that what the gauge says and what is really happening may not be the same. MegaSquirt has several tables that deal with things like cold enrichment, after start enrichment, cold advance, etc. I had some of them turned completely off, and several more minimized until I got a base tune. I've now turned a lot of that assistance on. I should be able to test my changes tomorrow. On 11/09/2011 08:04 AM, Lehanover@aol.com wrote: > At cold idle you would want a much richer mixture than a warm idle. I > cannot see the changes if any, even though I have a big screen. Street > cars bias pulse width with data from the coolant temperature sensor. > Timing at cold start could be 20 degrees and once you have a start > could go to 22 degrees. > 22 degrees is plenty until you are close to cruise power. Then as you > lean to cruise mixture, the timing can go up a bit to account for the > leaner (slower burning) mixture. > For closed throttle above idle RPM descents you can go up to 40 > degrees of advance. > Idle fuel flow but at high RPM you need extra time to burn the idle > mixture (the Renesis goes to 44 degrees), to keep the heat in the > rotors and prevent unburnt fuel from entering the exhaust and muffler, > lest the fuel ignite with surprising power and a big flame ball. Very > impressive in a race car but too spectacular for aviation use. > I would not put much faith in a F/A gage during throttle or RPM > transitions. At any RPM point if the pulse width and fuel pressure > didn't change then the mixture didn't change. > You will or may detect RPM/mixture combinations that report unhappy > tuning when you pass through various combinations of tuned length/back > pressure/timing settings. You can have cold air entering the muffler > and flowing quite a distance through it in some cases. Not so much in > Renesis engines with no overlap. Same thing around the oxygen sensor, > where gasses that have passed over the sensor come back over it in the > opposite direction. > So EGT probes and oxygen sensors are mounted on the outside of curves > where possible. > Never a problem in long exhaust systems. Airplanes tend to have very > short exhaust systems. > For full power tuning go too rich first. It is hard to hurt or stop a > rotary from too rich a mix. > Peak EGT is not good for apex seals. So stay rich of peak or well lean > of peak EGT. > If you tune too lean the engine will shut off just like the ignition > was cut. Just like your engine dying at idle. Just go richer and base > it on coolant temperature. > Just a guess though. > Lynn E. Hanover > In a message dated 11/9/2011 3:39:16 A.M. Paraguay Daylight Time, > echristley@nc.rr.com writes: > > Last night I turn the sound recorder on the laptop on while I did a > tuning run. I played back the data in MegaLogViewer while > recording the > screen, and then matched it up to the sound. I was hoping I could > get > suggestions for improving the tune. > > The first issue is the hard start. The only time I purposefully > turned > the engine off was at the very end. It runs pretty smooth, once > it is > warmed up to about 120*F, but below that the AFR will go off one > end of > the scale or the other, indicating that fuel isn't getting burned. > > http://www.youtube.com/watch?v=F3pYW1lOcTo&feature=youtu.be > > The top graph has RPM, manifold pressure and throttle position. > The second graph is injector pulse width time, AFR, and fuel flow. > Spark advance is on the third, along with mapDot and tpsDot. > Those are > measures of how quickly the map and throttle position are > changing. The > computer uses them to calculate how much to extra pulswidth to add on > acceleration. > The bottom graph show the oil temp, coolant temp and manifold air > temp. > Instantaneous values for each line show up at the center bottom of > each > graph. > The last line at the bottom is a run time timer. > > The bouncy balls to the right are the tables that the computer > uses to > calculate the injector pulse width and spark advance. Lowering the > numbers in the VE table tells the computer that the engine isn't > sucking > as much air as theoretically possible, and the computer will lower > the > amount of fuel at that combination of RPM and manifold pressure. > If the > ball is between cells, it uses a weighted average of the adjacent > ones. > It just pulls the number from the spark advance table and sends it > to my > EDIS modules. > > --------------030900000904050108050800 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit I think I have a tune file that will implement these recommendations.  I especially liked the comment about the F/A following the PW, regardless of what the AFR gauge says.  I was missing that, and thinking that I couldn't know what is going on when the gauge is finicky.  It's only finicky at cold startup, but it is always good to remember that what the gauge says and what is really happening may not be the same.

MegaSquirt has several tables that deal with things like cold enrichment, after start enrichment, cold advance, etc.  I had some of them turned completely off, and several more minimized until I got a base tune.  I've now turned a lot of that assistance on.  I should be able to test my changes tomorrow.

On 11/09/2011 08:04 AM, Lehanover@aol.com wrote:
At cold idle you would want a much richer mixture than a warm idle. I cannot see the changes if any, even though I have a big screen. Street cars bias pulse width with data from the coolant temperature sensor.
 
Timing at cold start could be 20 degrees and once you have a start could go to 22 degrees.
22 degrees is plenty until you are close to cruise power.  Then as you lean to cruise mixture, the timing can go up a bit to account for the leaner (slower burning)  mixture.
 
For closed throttle above idle RPM descents you can go up to 40 degrees of advance.
Idle fuel flow but at high RPM you need extra time to burn the idle mixture (the Renesis goes to 44 degrees), to keep the heat in the rotors and prevent unburnt fuel from entering the exhaust and muffler, lest the fuel ignite with surprising power and a big flame ball. Very impressive in a race car but too spectacular for aviation use.  
 
I would not put much faith in a F/A gage during throttle or RPM transitions. At any RPM point if the pulse width and fuel pressure didn't change then the mixture didn't change.
 
You will or may detect RPM/mixture combinations that report unhappy tuning when you pass through various combinations of tuned length/back pressure/timing settings. You can have cold air entering the muffler and flowing quite a distance through it in some cases. Not so much in Renesis engines with no overlap. Same thing around the oxygen sensor, where gasses that have passed over the sensor come back over it in the opposite direction.
 
So EGT probes and oxygen sensors are mounted on the outside of curves where possible.
 
Never a problem in long exhaust systems.  Airplanes tend to have very short exhaust systems.
 
For full power tuning go too rich first. It is hard to hurt or stop a rotary from too rich a mix.
Peak EGT is not good for apex seals. So stay rich of peak or well lean of peak EGT.
If you tune too lean the engine will shut off just like the ignition was cut. Just like your engine dying at idle. Just go richer and base it on coolant temperature.
 
Just a guess though.
 
Lynn E. Hanover
 
 
In a message dated 11/9/2011 3:39:16 A.M. Paraguay Daylight Time, echristley@nc.rr.com writes:
Last night I turn the sound recorder on the laptop on while I did a
tuning run.  I played back the data in MegaLogViewer while recording the
screen, and then matched it up to the sound.  I was hoping I could get
suggestions for improving the tune.

The first issue is the hard start.  The only time I purposefully turned
the engine off was at the very end.  It runs pretty smooth, once it is
warmed up to about 120*F, but below that the AFR will go off one end of
the scale or the other, indicating that fuel isn't getting burned.

http://www.youtube.com/watch?v=F3pYW1lOcTo&feature=youtu.be

The top graph has RPM, manifold pressure and throttle position.
The second graph is injector pulse width time, AFR, and fuel flow.
Spark advance is on the third, along with mapDot and tpsDot.  Those are
measures of how quickly the map and throttle position are changing.  The
computer uses them to calculate how much to extra pulswidth to add on
acceleration.
The bottom graph show the oil temp, coolant temp and manifold air temp.
Instantaneous values for each line show up at the center bottom of each
graph.
The last line at the bottom is a run time timer.

The bouncy balls to the right are the tables that the computer uses to
calculate the injector pulse width and spark advance.  Lowering the
numbers in the VE table tells the computer that the engine isn't sucking
as much air as theoretically possible, and the computer will lower the
amount of fuel at that combination of RPM and manifold pressure.  If the
ball is between cells, it uses a weighted average of the adjacent ones. 
It just pulls the number from the spark advance table and sends it to my
EDIS modules.



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