X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail07.syd.optusnet.com.au ([211.29.132.188] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTPS id 951549 for flyrotary@lancaironline.net; Fri, 20 May 2005 18:30:36 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.188; envelope-from=lendich@optusnet.com.au Received: from george (d211-31-163-235.dsl.nsw.optusnet.com.au [211.31.163.235]) by mail07.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j4KMTjtm023994 for ; Sat, 21 May 2005 08:29:47 +1000 Message-ID: <001a01c55d8c$148014b0$eba31fd3@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: More MAP measurement questions Date: Sat, 21 May 2005 08:34:26 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0017_01C55DDF.E5A8C3E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0017_01C55DDF.E5A8C3E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageEd, Good suggestion, I do like the EM2, in that it will probably save much = in the way of engine instruments and that it has the auto-tune = capability - I need simple !! George ( down under) Hi George, No experience with the EM2, but the EC2 is great. Dual CPUs, so you = have a degree of redundancy - but, even better you can play with two = different fuel maps with one stored for A controller and the other for B = controller. I leave one with Tracy's stock setting and play with the = other, that way I always have one fuel map that will run the engine to = switch to in case I really screw up something on one controller. Ed ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Friday, May 20, 2005 4:29 AM Subject: [FlyRotary] Re: More MAP measurement questions Ed, Rusty, Bill, Anyone. Here's another question - having little knowledge in the area, I'm = considering Tracy's ECU and the EM2. What are your appreciations of the products. Is it the EM2 which provides the auto tune capability ? George (down under) Hi George, I'll give it a shot. The Ec2 basically determines how much fuel = to inject using two factors - MAP (Manifold Absolute Pressure) and OAT = which basically tells it how dense the air is that the engine is = ingesting from the manifold. The Ec2 then examines its memory settings = (a different Map - read further)programmed in its memory (which you can = adjust with a mixture knob) for that manifold pressure match. Since the = manifold pressure can vary from apporx 12" Hg to 30"Hg (non-turbo), = there are a series of memory locations generally also referred to as the = MAP (MAP in this case referring to a topological chart) of the fuel = settings. If you plot the fuel mixture settings against RPM and Pressure = it looks like a 2 dim map). So once it matches the manifold pressure = it senses through the manifold pressure sensors with the corresponding = memory location it extracts the injector timing for that MAP and sends = it on to the injectors (with corrections for air temp). The injectors fire once per revolution of the E shaft (which = corresponds to one face of an rotor, therefore, the faster the rpm the = more frequently the injectors fire. But, it basically provides the same = amount of fuel per revolution per specific manifold pressure (which of = course is controlled by the throttle setting and engine rpm) perhaps = adjusted for Ve and OAT. Manifold Absolute Pressure is also one parameter to determine how = well you induction system is working. At sea level the MAP is 29.92" = Hg. So when you open your throttle wide open, you would like to see = 29.92" Hg on the gauge. If you do not and see less than 29.92"Hg (at = sea level) then that implies there is a restriction in your intake and a = resulting pressure loss. Less pressure means less dense air in the = manifold which means less fuel can be burnt which means less power. =20 That is the reason Rusty is concerned about whether the MAP he is = seeing really reflects what his engine is seeing or some fluke of where = the sensing port is in the intake. Generally you would like to have = less that 1/2" of a pressure drop any more than that (if its real) and = you are starting to loose power potential. So if the drop is real then = Rusty probably wants to modify his intake to eliminate it - if its just = a fluke of where he is sensing it - then he does not need to go to the = trouble of designing and fabricating a new intake. =20 That's my take on it. Hope it helps. Ed ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Thursday, May 19, 2005 2:13 AM Subject: [FlyRotary] Re: More MAP measurement questions Al,Rusty and All, Excuse my ignorance here, I have absolutely no knowledge about = how ECU's work. I've heard people say that it reads MAP settings - so = what is a MAP, and if it's different because the pressure is different = at different places in the inlet, how can the computer calculate the = inlet charge and timing. I'm confused! George ( down under) Greetings, I'm working on a new theory about my low MAP reading. The = theory is that this isn't a problem at all, but rather a difference in = the way it's being measured. =20 What's new about this theory? This is what I was telling you = a week or two ago. J I apologize for lack of clarity, causing you to have to = re-invent this theory. Al (Also running TWM TB) The TWM TB has a MAP port about 4 inches past the entrance of = the TB throat. That means I'm measuring the air pressure on the = suction side of the largest restriction in the system (from wide open = space, to 41mm tube). Since there's no significant restriction = downstream from the TB, I would guess that I could measure the MAP at = the inlet of the side housing, and wouldn't find it significantly lower = than what I'm seeing in the TWM TB. In other words, I'm measuring the = worst possible MAP, which is the suction side. =20 From what I understand, the typical (if there is such a thing) = intake has a large TB, feeding into an open plenum, then into the = smaller runners that go to the engine. If I'm not mistaken, virtually = everyone is measuring their MAP in the open plenum, before the air has = to enter the smaller runners to go to the engine. In other words, the = people who are reading 30" are doing it on the pressure side of the = largest restriction. =20 I could babble on about this, but my point is to ask where = others are measuring their MAP (turbo folks need not apply). You'll = also have to give a general description of your intake layout. I = already know that Ed and Tracy are using the "typical" situation. Is = anyone measuring MAP in the runner to the engine? =20 Cheers, Rusty (duty calls...) =20 ------=_NextPart_000_0017_01C55DDF.E5A8C3E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Ed,
Good suggestion, I do like the EM2, in = that it will=20 probably save much in the way of engine instruments and that it has the=20 auto-tune capability - I need simple !!
George ( down under)
Hi George,
 
No experience with the EM2, but the EC2 is = great. =20 Dual CPUs, so you have a degree of redundancy - but, even better you = can play=20 with two different fuel maps with one stored for A controller and the = other=20 for B controller.  I leave one with Tracy's stock setting and = play with=20 the other, that way I always have one fuel map that will run the = engine to=20 switch to in case I really screw up something on one = controller.
 
Ed
----- Original Message -----
From:=20 George Lendich
To: Rotary motors in = aircraft=20
Sent: Friday, May 20, 2005 = 4:29=20 AM
Subject: [FlyRotary] Re: More = MAP=20 measurement questions

Ed, Rusty, Bill, = Anyone.
Here's another question - having = little=20 knowledge in the area, I'm considering Tracy's ECU and the=20 EM2.
What are your appreciations of the=20 products.
Is it the EM2 which provides = the auto tune=20 capability ?
George (down under)
Hi George,
 
I'll give it a shot.  The Ec2 = basically=20 determines how much fuel to inject using two factors - MAP = (Manifold=20 Absolute Pressure) and OAT which basically tells it how dense the = air is=20 that the engine is ingesting from the manifold.  The Ec2 then = examines its memory settings (a different Map - read=20 further)programmed  in its memory (which you can adjust with = a=20 mixture knob) for that manifold pressure match.  Since the = manifold=20 pressure can vary from apporx 12" Hg to 30"Hg (non-turbo), there = are a=20 series of memory locations generally also referred to as the MAP = (MAP in=20 this case referring to a topological chart) of the fuel settings. = If you=20 plot the fuel mixture settings against RPM and Pressure it looks = like=20 a 2 dim map).    So once it matches the manifold = pressure=20 it senses through the manifold pressure sensors with the = corresponding=20 memory location it extracts the injector timing for that MAP and = sends it=20 on to the injectors (with corrections for air temp).
 
The injectors fire once per revolution of = the E=20 shaft (which corresponds to one face of an rotor, therefore, the = faster=20 the rpm the more frequently the injectors fire.  But, it = basically=20 provides the same amount of fuel per revolution per specific = manifold=20 pressure (which of course is controlled by the throttle setting = and engine=20 rpm) perhaps adjusted for Ve and OAT.
 
Manifold Absolute Pressure is also one = parameter to=20 determine how well you induction system is working.  At sea = level the=20 MAP is 29.92" Hg.  So when you open your throttle wide open, = you=20 would like to see 29.92" Hg on the gauge.  If you do not and = see less=20 than 29.92"Hg (at sea level) then that implies there is a = restriction in=20 your intake and a resulting pressure loss.  Less pressure = means less=20 dense air in the manifold which means less fuel can be burnt which = means=20 less power.  
 
That is the reason Rusty is concerned = about whether=20 the MAP he is seeing really reflects what his engine is seeing or = some=20 fluke of where the sensing port is in the intake.  Generally = you=20 would like to have less that 1/2" of a pressure drop any more than = that=20 (if its real) and you are starting to loose power potential.  = So if=20 the drop is real then Rusty probably wants to modify his intake to = eliminate it - if its just a fluke of where he is sensing it - = then he=20 does not need to go to the trouble of designing and fabricating a = new=20 intake. 
 
That's my take on it.  Hope it=20 helps.
 
Ed
----- Original Message ----- =
From:=20 George Lendich =
To: Rotary motors in = aircraft=20
Sent: Thursday, May 19, = 2005 2:13=20 AM
Subject: [FlyRotary] Re: = More MAP=20 measurement questions

Al,Rusty and All,
Excuse my ignorance here, I = have absolutely=20 no knowledge about how ECU's work. I've heard people say that it = reads=20 MAP settings - so what is a MAP, and if it's different because = the=20 pressure is different at different places in the inlet, how can = the=20 computer calculate the inlet charge and timing.
I'm confused!
George ( down = under)

 

Greetings,

 

I'm working=20 on a new theory about my low MAP reading.  The theory is = that=20 this isn't a problem at all, but rather a difference in the = way it's=20 being measured. 

 

What=92s new=20 about this theory?  This is what I was telling you a week = or two=20 ago. J

I = apologize=20 for lack of clarity, causing you to have to re-invent this=20 theory.

 

Al (Also=20 running TWM TB)

 

The TWM TB=20 has a MAP port about 4 inches past the entrance of the TB=20 throat.   That means I'm measuring the air pressure = on the=20 suction side of the largest restriction in the system (from = wide open=20 space, to 41mm tube).   Since there's no significant = restriction downstream from the TB, I would guess that I = could=20 measure the MAP at the inlet of the side housing, and = wouldn't=20 find it significantly lower than what I'm seeing in the TWM=20 TB.  In other words, I'm measuring the worst = possible MAP,=20 which is the suction side. =20   

 

From what I=20 understand, the typical (if there is such a thing) intake has = a large=20 TB, feeding into an open plenum, then into the smaller = runners=20 that go to the engine.  If I'm not mistaken, = virtually=20 everyone is measuring their MAP in the open plenum, before the = air has=20 to enter the smaller runners to go to the = engine.  In=20 other words, the people who are reading 30" are doing it = on the=20 pressure side of the largest=20 restriction.  

 

I = could=20 babble on about this, but my point is to ask where others are=20 measuring their MAP (turbo folks need not apply).  You'll = also=20 have to give a general description of your intake = layout.  =20 I already know that Ed and Tracy are using the "typical"=20 situation.  Is anyone measuring MAP in the runner to the=20 engine?  

 

Cheers,

Rusty (duty=20 calls...)

 =20 =

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