X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao102.cox.net ([68.230.241.44] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4234174 for flyrotary@lancaironline.net; Mon, 26 Apr 2010 01:22:05 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.44; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao102.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100426052130.ZOUA20234.fed1rmmtao102.cox.net@fed1rmimpo03.cox.net> for ; Mon, 26 Apr 2010 01:21:30 -0400 Received: from willsPC ([174.66.169.142]) by fed1rmimpo03.cox.net with bizsmtp id A5MV1e00834gpFS045MVN7; Mon, 26 Apr 2010 01:21:29 -0400 X-VR-Score: -70.00 X-Authority-Analysis: v=1.1 cv=b4II0uhcJPnwjva2/FqJSYAtAoopJitAe4Ogu0tU6w4= c=1 sm=1 a=jZ489fqmLCIA:10 a=cPUexvdKvEVW1PN6gG+JiA==:17 a=Ia-xEzejAAAA:8 a=pedpZTtsAAAA:8 a=-wtcJwQAc6X87zTFI2AA:9 a=dB7cJ7TOsP5httwDersA:7 a=mhUoYI75xy70rrpV0l00gvk_pjEA:4 a=pILNOxqGKmIA:10 a=EzXvWhQp4_cA:10 a=eJojReuL3h0A:10 a=R9KGrc9WInGpPmXp:21 a=Ffas6hCEv8heEpRy:21 a=cyKPeHffyHktm32HIA8A:9 a=5NFA3z6mYn85TWHbw8EA:7 a=YtUtcFtfbITNMThPwAe10NWH67cA:4 a=q39TO4fE_H6tW0Hh:21 a=3zvumXxoiOA_6sDr:21 a=cPUexvdKvEVW1PN6gG+JiA==:117 X-CM-Score: 0.00 Message-ID: <4D24B5F6E1E341859E6CAC3F3AB2906F@willsPC> From: "Mike Wills" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: getting lost in the tuning process Date: Sun, 25 Apr 2010 22:21:28 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0078_01CAE4C5.A68FE9A0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_0078_01CAE4C5.A68FE9A0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable That=92s just not fair. And honestly I don=92t understand how it worked = so well for you without any tuning required at all. On completely = different engines. Mine was a bear to get right. In fact never really = did get it completely right, but close enough to fly safely. Then I = pulled the wrecking yard injectors and installed my overhauled injectors = hoping to get more balanced egts across the full rpm range. With the = replacement injectors, more tuning required. But unlike a carb at least = its easy to tune in real time. Mike Wills From: Steven W. Boese=20 Sent: Sunday, April 25, 2010 11:29 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: getting lost in the tuning process If I may relate my own recent experience with the tuning process... There are two systems that I have been working with. One is my flying = RV6A with a 1986 13B NA with 4 stock peak and hold (low resistance) fuel = injectors, stock CAS, an intake manifold with no intentional dynamic = tuning, and GM ignition coils. The other is a test stand with a 1987 = 13B NA with 4 stock saturated (high resistance) fuel injectors, stock = CAS, also with GM ignition coils. The propellers are quite similar = although of different manufacturers. Both systems have EC2's with chips = that were updated early in 2010. After installing the updated chips in the plane's EC2, I made sure that = I had studied the latest copy of the installation manual. I also had = the IPAQ EC2 recording system described elsewhere set up to document my = tuning steps so I could review it after the fact to assure myself that I = had done things in a reasonable fashion. Starting with the default = settings in the EC2, I found to my great dissapointment ;) that no = changes in the default settings were needed. I could use just the = manual mixture control to run from rich of peak to lean of peak EGT at = any throttle setting available. Max MAP for my location with a field = elveation of 7200 ft is always near 23 inches of Hg. A couple of days = ago, I flew from home (Laramie, WY) to Benson, MN at altitudes ranging = from 12000 ft to 1300 ft and OAT's ranging from the 20's to 60's, with = those default EC2 settings and using the manual mixture control to = select the desired operating conditions. There wasn't any hint of an = improvement to be gained from tuning the power plant any differently. The engine stand which we took to the Contact Magazine fly-in last month = has performed similarly. No change from the default settings has been = required using either the stock automotive intake system with the = dynamic chamber or a second intake system that I got with the engine. = This second intake system has secondary runners controlled by the double = butterfly of a cut down stock throttle body and primary runners = controlled by the single butterfly of that throttle body. There is no = pneumatic connection between the primary and secondary runners except = for MAP sensing lines tee'd together and going to the EC2. There is a = mechanical linkage on the throttle body between the primary butterfly = and and the double butterfly, of course. I tested this manifold just = because it was available, thinking that there was no way this would work = very well. It performed very nearly as well as the stock dynamic = chamber, again with the default EC2 settings. Probably, the the important thing that these systems have in common are = the 4 stock fuel injectors all of the same flow characteristics. Personally, it has been most useful (if I set the staging point = different than default) to set the staging point to a setting such that = the two primary injectors are used to as high a MAP as possible without = them limiting the fuel flow at about 80% duty cycle. I do this because = there is a lower limit to the amount of fuel that the injectors can = deliver reliably. This lower limit occurs at about 1.5 to 2 ms pulse = width with the injectors I have tested. Below this limit, the amount of = fuel delivered is more a function of the injector dynamics than it is a = function of what the EC2 is requesting of it. If the staging point is = set too low, one is just getting into the range where the two injectors = are working predictably and then the system switches to using 4 = injectors, each one trying to deliver fuel in such small amounts that = they are somewhat unpredictable. The dynamic range adjustment in the = EC2 may be able to compensate for the low flow non-linearity to some = extent, but it seems to me that this would be most useful to obtain good = idle characteristics with two injectors rather than using 4 injectors at = relatively low but non-idle power settings. Setting the staging point = to a low MAP may be useful as an exercise in learning the steps involved = in tuning the EC2 while avoid cooling porblems on the ground, but I = suspect that it will be frustrating if the resulting parameters are = expected to work well in flight. It seems to me that it will be much = more productive to temporarily resolve the ground cooling issue and = program the EC2 under conditions as close to the power levels that would = be encountered in flight as possible. Please note that these are just my thoughts based on the special cases I = have to work with and there is absolutely no criticism intended toward = anyone. This email may also be the result of being away from home on a = gloomy day unfit for flying. Steve Boese =20 =20 -------------------------------------------------------------------------= ------- From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf = Of Bill Bradburry [bbradburry@bellsouth.net] Sent: Sunday, April 25, 2010 7:41 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: getting lost in the tuning process You certainly have it right about the better understanding part! :>) So, since it has no effect, why, in step 1, do you say, =93with the = engine running below the staging point, select mode 6 and turn the = program knob slightly to the left of the 12:00 oclock position and press = the program store switch=94??? Is this some kind of arming step?? The mixture is really rich before I start this step. I have the mixture = control knob at probably 9:00 oclock on both sides of 15=94 of map. Is = this going to have an effect on that? Or is it just in case the mixture = changes when you go from below 15 to above 15? With the 4 yellow injectors, where do you recommend the staging point be = set? I have it set now at 15 mostly so I can do stuff like this without = running at high power and causing ground cooling problems. If I get = every thing set and then later change the staging point, will this cause = a need for a do over? =20 I will clear and start over. When would be a good time to call if need = be? Thanks for the response that helps to clear it up. By the way, to those carb guys, this is a little confusing, but no way = bad enough to justify going with a carburetor!!! Bill B ------=_NextPart_000_0078_01CAE4C5.A68FE9A0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
That=92s just not fair. And honestly I don=92t = understand=20 how it worked so well for you without any tuning required at all. On = completely=20 different engines. Mine was a bear to get right. In fact never = really did=20 get it completely right, but close enough to fly safely. Then I pulled = the=20 wrecking yard injectors and installed my overhauled injectors hoping to = get more=20 balanced egts across the full rpm range. With the replacement injectors, = more=20 tuning required. But unlike a carb at least its easy to tune in real=20 time.
 
Mike Wills

Sent: Sunday, April 25, 2010 11:29 AM
Subject: [FlyRotary] Re: getting lost in the tuning=20 process

If I may = relate my own=20 recent experience with the tuning process...
 
There are two systems that I = have been=20 working with.  One is my flying RV6A with a 1986 13B NA with 4 = stock peak=20 and hold (low resistance) fuel injectors, stock CAS, an intake = manifold=20 with no intentional dynamic tuning, and GM ignition = coils.  The=20 other is a test stand with a 1987 13B NA with 4 stock saturated (high=20 resistance) fuel injectors, stock CAS, also with GM ignition=20 coils.  The propellers are quite similar although of different=20 manufacturers.  Both systems have EC2's with chips that were = updated early=20 in 2010.
 
After installing the updated = chips in the=20 plane's EC2, I made sure that I had studied the latest copy of the=20 installation manual.  I also had the IPAQ EC2 recording system = described=20 elsewhere set up to document my tuning steps so I could review it after = the fact=20 to assure myself that I had done things in a reasonable fashion.  = Starting=20 with the default settings in the EC2, I found to my great dissapointment = ;) that=20 no changes in the default settings were needed.  I could use just = the=20 manual mixture control to run from rich of peak to lean of = peak EGT at=20 any throttle setting available.  Max MAP for my location with a = field=20 elveation of 7200 ft is always near 23 inches of Hg.  A couple of = days ago,=20 I flew from home (Laramie, WY) to Benson, MN at altitudes ranging = from=20 12000 ft to 1300 ft and OAT's ranging from the 20's to = 60's, with=20 those default EC2 settings and using the manual mixture control to = select the=20 desired operating conditions.  There wasn't any hint of an = improvement to=20 be gained from tuning the power plant any differently.
 
The engine stand which we = took to the=20 Contact Magazine fly-in last month has performed similarly.  No = change from=20 the default settings has been required using either the stock automotive = intake=20 system with the dynamic chamber or a second intake system that I got = with the=20 engine.  This second intake system has secondary runners controlled = by the=20 double butterfly of a cut down stock throttle body and primary runners=20 controlled by the single butterfly of that throttle body.  = There is no=20 pneumatic connection between the primary and secondary runners except=20 for MAP sensing lines tee'd together and going to the = EC2.  There=20 is a mechanical linkage on the throttle body between the primary = butterfly and=20 and the double butterfly, of course.  I tested this manifold just = because=20 it was available, thinking that there was no way this would work very=20 well.  It performed very nearly as well as the stock dynamic = chamber, again=20 with the default EC2 settings.
 
Probably, the the=20 important thing that these systems have in common are the 4 stock fuel = injectors=20 all of the same flow characteristics.
 
Personally, it has been most = useful (if I set the staging point different than default) to set = the=20 staging point to a setting such that the two primary injectors = are=20 used to as high a MAP as possible without them limiting the fuel=20 flow at about 80% duty cycle.  I do this because there is = a lower=20 limit to the amount of fuel that the injectors can deliver = reliably.  This=20 lower limit occurs at about 1.5 to 2 ms pulse width with the = injectors I=20 have tested.  Below this limit, the amount of fuel delivered is = more a=20 function of the injector dynamics than it is a function of what the EC2 = is=20 requesting of it.  If the staging point is set too low, one is just = getting=20 into the range where the two injectors are working predictably and then = the=20 system switches to using 4 injectors, each one trying to deliver=20 fuel in such small amounts that they are somewhat = unpredictable. =20 The dynamic range adjustment in the EC2 may be able to compensate for = the low=20 flow non-linearity to some extent, but it seems to me that this would be = most=20 useful to obtain good idle characteristics with two = injectors rather=20 than using 4 injectors at relatively low but non-idle power = settings. =20 Setting the staging point to a low MAP may be useful as an exercise in = learning=20 the steps involved in tuning the EC2 while avoid cooling porblems = on the=20 ground, but I suspect that it will be frustrating if the=20 resulting parameters are expected to work well in flight.  It = seems to=20 me that it will be much more productive to temporarily resolve=20 the ground cooling issue and program the EC2 under conditions as = close to=20 the power levels that would be encountered in flight as = possible.
 
Please = note that these=20 are just my thoughts based on the special cases I have to work with and = there is=20 absolutely no criticism intended toward anyone.  This email = may also=20 be the result of being away from home on a gloomy day unfit for=20 flying.
 
Steve Boese
 
 
          
 
     =
From: Rotary motors in aircraft=20 [flyrotary@lancaironline.net] On Behalf Of Bill Bradburry=20 [bbradburry@bellsouth.net]
Sent: Sunday, April 25, 2010 7:41=20 AM
To: Rotary motors in aircraft
Subject: = [FlyRotary] Re:=20 getting lost in the tuning process

You certainly = have it=20 right about the better understanding part!  = :>)

 

So, since it = has no=20 effect, why, in step 1, do you say, =93with the engine running below the = staging=20 point, select mode 6 and turn the program knob slightly to the left of = the 12:00=20 oclock position and press the program store = switch=94???

Is this some = kind of=20 arming step??

 

The mixture = is really=20 rich before I start this step.  I have the mixture control knob at = probably=20 9:00 oclock on both sides of 15=94 of map.  Is this going to have = an effect=20 on that?  Or is it just in case the mixture changes when you go = from below=20 15 to above 15?

 

With the 4 = yellow=20 injectors, where do you recommend the staging point be set?  I have = it set=20 now at 15 mostly so I can do stuff like this without running at high = power and=20 causing ground cooling problems.  If I get every thing set and then = later=20 change the staging point, will this cause a need for a do over? =20

 

I will clear = and start=20 over.  When would be a good time to call if need = be?

 

Thanks for = the response=20 that helps to clear it up.

 

By the way, = to those=20 carb guys, this is a little confusing, but no way bad enough to justify = going=20 with a carburetor!!!

 

Bill=20 B

 

 

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