X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail06.syd.optusnet.com.au ([211.29.132.187] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTPS id 949561 for flyrotary@lancaironline.net; Thu, 19 May 2005 02:09:59 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.187; envelope-from=lendich@optusnet.com.au Received: from george (d211-31-84-130.dsl.nsw.optusnet.com.au [211.31.84.130]) by mail06.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j4J691bC014055 for ; Thu, 19 May 2005 16:09:05 +1000 Message-ID: <001301c55c39$e7787690$82541fd3@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: More MAP measurement questions Date: Thu, 19 May 2005 16:13:38 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C55C8D.B77D3F30" 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_0010_01C55C8D.B77D3F30 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageAl,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_0010_01C55C8D.B77D3F30 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Al,Rusty and All,
Excuse my ignorance here, I have = absolutely no=20 knowledge about how ECU's work. I've heard people say that it reads MAP = settings=20 - so what is a MAP, and if it's different because the pressure is = different at=20 different places in the inlet, how can the computer calculate the inlet = charge=20 and timing.
I'm confused!
George ( down under)

 

Greetings,

 

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

 

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

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

 

Al (Also = running=20 TWM TB)

 

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

 

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

 

I could babble on about = this, but=20 my point is to ask where others are measuring their MAP (turbo folks = need not=20 apply).  You'll also have to give a general description of your = intake=20 layout.   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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