X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from willowsprings.uwyo.edu ([129.72.10.31] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTPS id 4988669 for flyrotary@lancaironline.net; Thu, 19 May 2011 11:31:46 -0400 Received-SPF: none receiver=logan.com; client-ip=129.72.10.31; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht2.uwyo.edu (ponyexpress-ht2.uwyo.edu [10.84.60.209]) by willowsprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id p4JFV6Cq005352 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Thu, 19 May 2011 09:31:07 -0600 (MDT) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9813:248c:2d68:a28b]) by ponyexpress-ht2 ([10.84.60.209]) with mapi; Thu, 19 May 2011 09:31:05 -0600 From: "Steven W. Boese" To: Rotary motors in aircraft Date: Thu, 19 May 2011 09:30:53 -0600 Subject: RE: [FlyRotary] Re: Engine Tuning Thread-Topic: [FlyRotary] Re: Engine Tuning Thread-Index: AcwWI/D9nuKodQwiQ2aemb5BOU2XfAAC3aQQ Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E1AA3B1AF41D8049B1E3FBD5E2256260088BCDEF22ponyexpressmb_" MIME-Version: 1.0 --_000_E1AA3B1AF41D8049B1E3FBD5E2256260088BCDEF22ponyexpressmb_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Jeff, One way of reading the controller parameters is described in the following = website: www.rotarycopilot.com/ The software to do this can be downloaded from this site. If you already h= ave a computer, the only cost to do this is the voltage converter for the s= erial connection, the wiring to the controller which may already be install= ed, and the time invested. There is some indication that this data is available from the EM2/3 display= . It may be in hexadecimal format but converting that to decimal would be = straightforward. I don't have an EM2/3 so I am not positive that this is t= he case. I have been flying with a default (flat line at midrange zero) mixture corr= ection table for some time now with good results. The tuning was performed= as you describe. A default mixture correction table has also been used on= my engine test stand with various combinations of different sized primary = and secondary injectors giving equally good results. The values for mode 3, mode 6, the mixture control, and the mixture correct= ion table all appear to be used to calculate an injector pulse width for a = given manifold pressure and appear to be independent and additive. The value at a particular address in the mixture correction table is not a = pulse width, but a value used along with the others to calculate the pulse = width to be used. I am not aware of a readout of the pulse width in use th= at is directly available from the EC or EM equipment and have assembled my = own equipment for this purpose. The pulse width itself tells nothing about fuel delivery. When combined wi= th the injector characteristics, however, it very accurately defines the fu= el delivery. The controller has no initial knowledge of what the injector characteristic= s are or if an injector is even connected to it. This information is suppl= ied by feedback from the person doing the tuning through the adjustments of= the parameters mentioned. In Brian's case, I'm just suggesting that the feedback may have produced pa= rameters that result in long enough pulse widths to cause static injector o= peration at the RPM's he is capable of attaining. That particular combinat= ion of parameters (and many others) would produce static injector operation= regardless of what injector would be connected to the controller. The use= of larger injectors may not have resulted in feedback leading to that comb= ination of parameters, of course. I am not contending that this is actuall= y happening, but that it is possible and easy to verify. I agree that the best way to monitor fuel flow would be through the use of = a fuel flow meter. Preferably one based on a sensor such as a Floscan type= which is independent of the rest of the fuel system, but unfortunately exp= ensive. In the end, the engine will tell the operator if it is happy or no= t and the operator would already know this before looking at the fuel flow = meter. The O2 sensor seems to be more useful in keeping the engine happy. I hope I have interpreted your message correctly and my response is just my= way of looking at things with no claim of absolute certainty. Steve -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Jeff Whaley Sent: Thursday, May 19, 2011 6:55 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Engine Tuning Hi Steve, I always find something interesting in your reports, in this one = I'm most interested in how you know what the Mode 3 and Mode 6 correction v= alues are. Are they displayed by an EM2/3 or do you have something custom o= f your own making? If you start with ALL DEFAULTS then adjust Injector Flow rate with Mode 3, = followed by Mode 6 and maybe Mode 2 your Mixture Correction Table would be = a flat line at either 0 if display is -128 to +128 or it would be 128 if di= splay is 0 to 256. Which in my opinion tells you nothing about fuel deliver= y - the only way to know what your fuel delivery is in this scenario would = be to display the injector pulse width from BIN 1-128 or read your fuel flo= w meter. Jeff --_000_E1AA3B1AF41D8049B1E3FBD5E2256260088BCDEF22ponyexpressmb_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Jeff,

 

<= p class=3DMsoPlainText>One way of reading the controller parameters is d= escribed in the following website:

www.rotarycopilot.com/

The software to do this c= an be downloaded from this site.  If you already have a computer, the = only cost to do this is the voltage converter for the serial connection, th= e wiring to the controller which may already be installed, and the time inv= ested.

 

There is some indication that this data = is available from the EM2/3 display.  It may be in hexadecimal format = but converting that to decimal would be straightforward.  I don’= t have an EM2/3 so I am not positive that this is the case.

 

I have been flying with a default (flat line at midrange zero)= mixture correction table for some time now with good results.  The tu= ning was performed as you describe.  A default mixture correction tabl= e has also been used on my engine test stand with various combinations of d= ifferent sized primary and secondary injectors giving equally good results.=

 

The values for mode 3, mode 6, the mixture con= trol, and the mixture correction table all appear to be used to calculate a= n injector pulse width for a given manifold pressure and appear to be indep= endent and additive. 

 

The value at a part= icular address in the mixture correction table is not a pulse width, but a = value used along with the others to calculate the pulse width to be used.&n= bsp; I am not aware of a readout of the pulse width in use that is directly= available from the EC or EM equipment and have assembled my own equipment = for this purpose.

&nb= sp;

The pulse width itself tells= nothing about fuel delivery.  When combined with the injector charact= eristics, however, it very accurately defines the fuel delivery. 

 

The controller has no initial knowledge of what th= e injector characteristics are or if an injector is even connected to it.&n= bsp; This information is supplied by feedback from the person doing the tun= ing through the adjustments of the parameters mentioned.<= /p>

 

In Brian’s case, I’m just suggesting that the feedbac= k may have produced parameters that result in long enough pulse widths to c= ause static injector operation at the RPM’s he is capable of attainin= g.  That particular combination of parameters (and many others) would = produce static injector operation regardless of what injector would be conn= ected to the controller.  The use of larger injectors may not have res= ulted in feedback leading to that combination of parameters, of course.&nbs= p; I am not contending that this is actually happening, but that it is poss= ible and easy to verify.

 

I agree that the best = way to monitor fuel flow would be through the use of a fuel flow meter.&nbs= p; Preferably one based on a sensor such as a Floscan type which is indepen= dent of the rest of the fuel system, but unfortunately expensive.  In = the end, the engine will tell the operator if it is happy or not and the op= erator would already know this before looking at the fuel flow meter. = The O2 sensor seems to be more useful in keeping the engine happy.

 

I hope I have interpreted your message correctly and m= y response is just my way of looking at things with no claim of absolute ce= rtainty.

 <= /span>

Steve      

 

 

-----Original = Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancairon= line.net] On Behalf Of Jeff Whaley
Sent: Thursday, May 19, 2011 6:55 AM<= br>To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Engine Tuning<= o:p>

 

Hi Steve, I always find something interesting in your reports, in t= his one I'm most interested in how you know what the Mode 3 and Mode 6 corr= ection values are. Are they displayed by an EM2/3 or do you have something = custom of your own making?

 = ;

If you start with ALL DEFAULTS then adju= st Injector Flow rate with Mode 3, followed by Mode 6 and maybe Mode 2 your= Mixture Correction Table would be a flat line at either 0 if display is -1= 28 to +128 or it would be 128 if display is 0 to 256. Which in my opinion t= ells you nothing about fuel delivery - the only way to know what your fuel = delivery is in this scenario would be to display the injector pulse width f= rom BIN 1-128 or read your fuel flow meter.

Jeff

 

 

= --_000_E1AA3B1AF41D8049B1E3FBD5E2256260088BCDEF22ponyexpressmb_--