Return-Path: Received: from imf24aec.mail.bellsouth.net ([205.152.59.72] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 557878 for flyrotary@lancaironline.net; Mon, 06 Dec 2004 14:05:13 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.72; envelope-from=atlasyts@bellsouth.net Received: from [65.11.186.32] by imf24aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20041206190443.HCUN2421.imf24aec.mail.bellsouth.net@[65.11.186.32]> for ; Mon, 6 Dec 2004 14:04:43 -0500 User-Agent: Microsoft-Entourage/10.1.4.030702.0 Date: Mon, 06 Dec 2004 14:04:35 -0500 Subject: Re: [FlyRotary] Re: ECU oxygen sensor From: Bulent Aliev To: Rotary motors in aircraft Message-ID: In-Reply-To: Mime-version: 1.0 Content-type: multipart/alternative; boundary="B_3185186678_8793721" > This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --B_3185186678_8793721 Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit On 12/6/04 12:02 PM, "Russell Duffy" <13brv3@bellsouth.net> wrote: > I have been looking at various ECUs trying to understand how they > work. > > Fortunately, I was on the phone, and Ed just saved me a lot of typing :-) > One additional note, ECU's can run in open loop, or closed loop modes. > Tracy's EC-2 is open loop all the time. Basically, in open loop, you supply a > pre-designated amount of fuel from a look-up table, and you trust that it's > what you wanted. When we tune the EC-2, we're making this look-up table. In > closed loop mode, you start with the look up table number, then check the O2 > sensor to see how close you came. The ECU can add or remove fuel as needed to > hit a target O2 number. > > Cars use closed loop whenever they can, or emissions and fuel efficiency, but > they also run in open loop mode under certain conditions. For example, you're > car will run in open loop mode when you first start it, because there's no > valid O2 sensor reading until it warms up. Multi-wire heated O2 sensors have > shortened this time considerably over the years. I think most cars also run > in open loop mode during full throttle operation. > > Rusty > Sooo, I installed an 02 sensor for nothing? Bulent --B_3185186678_8793721 Content-type: text/html; charset="US-ASCII" Content-transfer-encoding: quoted-printable Re: [FlyRotary] Re: ECU oxygen sensor On 12/6/04 12:02 PM, &q= uot;Russell Duffy" <13brv3@bellsouth.net> wrote:

I have been looking at various ECUs trying to understand how they
work.  

Fortunately, I was on the phone, and Ed just saved me a lot of ty= ping :-)   One additional note, ECU's can run in open loop, or clo= sed loop modes.  Tracy's EC-2 is open loop all the time.  Basicall= y, in open loop, you supply a pre-designated amount of fuel from a look-up t= able, and you trust that it's what you wanted.  When we tune the EC-2, = we're making this look-up table.  In closed loop mode, you start with t= he look up table number, then check the O2 sensor to see how close you came.=  The ECU can add or remove fuel as needed to hit a target O2 number.
Cars use closed loop whenev= er they can, or emissions and fuel efficiency, but they also run in open loo= p mode under certain conditions.  For example, you're car will run in o= pen loop mode when you first start it, because there's no valid O2 sensor re= ading until it warms up.  Multi-wire heated O2 sensors have shortened t= his time considerably over the years.   I think most cars also run= in open loop mode during full throttle operation.

Rusty    

Sooo, I installed an 02 sensor for nothing?
Bulent --B_3185186678_8793721--