X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 12 Jun 2007 18:30:55 -0400 Message-ID: X-Original-Return-Path: Received: from wx-out-0506.google.com ([66.249.82.230] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2098668 for lml@lancaironline.net; Tue, 12 Jun 2007 15:16:37 -0400 Received-SPF: pass receiver=logan.com; client-ip=66.249.82.230; envelope-from=akadamson@gmail.com Received: by wx-out-0506.google.com with SMTP id t11so5807281wxc for ; Tue, 12 Jun 2007 12:16:00 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:from:to:references:subject:date:message-id:mime-version:content-type:x-mailer:x-mimeole:thread-index:in-reply-to:sender; b=H3OhnCRm+oafgFKOx+TD+uzsjtIDhQMStvBlXA0B6n5zZZSMp6IAtnFkkFuhWU9LwLNntRER6TdCfY4BzfSxdyJMsFPIAifIUC2aYVMKatfWh2odH6JDXzufqJV1bMyabq/5VBmrRmaA5TfjAk9gj1U77PqkukGcVLJgXZ29QzY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:from:to:references:subject:date:message-id:mime-version:content-type:x-mailer:x-mimeole:thread-index:in-reply-to:sender; b=MnIyffY6WItDUzo/JtypBW0rvI27uislSlPwNiuWulYogjEnzFyXW0jgJfBGWY5ZIsqAYkuyaujsqQhNyaMsdCsIAHRxtSStonWQzBpSXANOaqCjzKIY+HlfDv+lkpo5AaupD8Vq2P5vjevgLE/9ZgrByUzstCGOXiI8xSuCbnw= Received: by 10.90.50.1 with SMTP id x1mr7053121agx.1181675760361; Tue, 12 Jun 2007 12:16:00 -0700 (PDT) X-Original-Return-Path: Received: from Typhoon ( [76.97.47.101]) by mx.google.com with ESMTP id 32sm10046121aga.2007.06.12.12.15.58 (version=SSLv3 cipher=RC4-MD5); Tue, 12 Jun 2007 12:15:58 -0700 (PDT) From: "Alan Adamson" X-Original-To: "'Lancair Mailing List'" References: Subject: RE: [LML] Re: Boost switch X-Original-Date: Tue, 12 Jun 2007 15:15:55 -0400 X-Original-Message-ID: <014501c7ad26$1be1e4e0$2201a8c0@highrf.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0146_01C7AD04.94D044E0" X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 Thread-Index: Acesjs22cZAqZl01QXeBSAgVUoLzzwAAIn1A In-Reply-To: X-Original-Sender: Alan Adamson This is a multi-part message in MIME format. ------=_NextPart_000_0146_01C7AD04.94D044E0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I'm not sure about "suicidal" either, but yes I do understand why you'd feel that way... That is why it would need to be tested which should be pretty simple in run-up, etc. Also, I much prefer the "ARMED" approach. To that end in my Legacy, as most know I'm going to be beta testing the Vertical Power modules in my Legacy. I've been talking with the designers about this issue and they will most likely implement a form of "ARMED" detection/triggering where you can setup a programmatically rule to address emergency conditions around the boost pump. This may allow picking the percent power where an abrupt fuel pressure reading going to zero or below some settable threshold would trigger the "Emergency Boost mode". It may also allow for automatic triggering of the boost pump (either low or high) at specific altitudes, etc. Mind you, these "software features" do not exist today, but the capability certainly does with their system. But short of their system, the logical thing to do based upon what Continental told me, is to determine if HIGH boost causes the engine to get too much fuel in run-up, etc. Then to determine if there is a "simple" way to develop a "retro" option to support this concept of "ARMED". It would nice to know what Columbia uses as the "triggering" mechanism. It can't be fuel pressure alone as it is RPM dependant (this is a engine driven pump we are trying to figure out right?). *WITH NO SPECIFIC KNOWLEDGE*, it does seem that because the Dukes pump is *pre* the engine, that too much fuel really can't happen, it's metered by the fuel divider and if the throttle body is not open, then the fuel is returned via the return line. So in effect you are just pumping fuel back into the tanks via the return line.... Course like I said, I have no specific knowledge, just conjecture on how the fuel system works. I do know tho that some people use the high boost mode to purge the vapor out of the lines after shutdown or before startup. They simply allow the pump to circulate cool fuel throughout the lines, which is why I assume that the injectors can only take a Max amount of fuel and the remainder is shuttled back to the tanks via return lines... As I also said, I wish this wasn't all "black art" and that there was a scientific way to determine the optimal in all conditions... Alan _____ From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of marv@lancair.net Sent: Monday, June 11, 2007 9:13 PM To: lml@lancaironline.net Subject: [LML] Re: Boost switch Posted for "Colyn Case on earthlink" : Alan, I suspect high boost + a working mechanical pump on TO would be fairly suicidal but I can't say that from experience. (hmmmm......) Colyn -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_0146_01C7AD04.94D044E0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
I'm not sure about "suicidal" either, but yes I = do=20 understand why you'd feel that way... That is why it would need to be = tested=20 which should be pretty simple in run-up, etc.  Also, I much prefer = the=20 "ARMED" approach.  To that end in my Legacy, as most know I'm going = to be=20 beta testing the Vertical Power modules in my = Legacy.
 
I've been talking with the designers about this = issue and=20 they will most likely implement a form of "ARMED" detection/triggering = where you=20 can setup a programmatically rule to address emergency conditions around = the=20 boost pump.  This may allow picking the percent power where an = abrupt fuel=20 pressure reading going to zero or below some settable threshold would = trigger=20 the "Emergency Boost mode".  It may also allow for automatic = triggering of=20 the boost pump (either low or high) at specific altitudes, = etc.  Mind=20 you, these "software features" do not exist today, but the capability = certainly=20 does with their system.
 
But short of their system, the logical thing to = do based=20 upon what Continental told me, is to determine if HIGH boost causes the = engine=20 to get too much fuel in run-up, etc.  Then to determine if there is = a=20 "simple" way to develop a "retro" option to support this concept of=20 "ARMED".  It would nice to know what Columbia uses as the = "triggering"=20 mechanism.  It can't be fuel pressure alone as it is RPM dependant = (this is=20 a engine driven pump we are trying to figure out = right?).
 
*WITH NO SPECIFIC KNOWLEDGE*, it does seem that = because the=20 Dukes pump is *pre* the engine, that too much fuel really can't happen, = it's=20 metered by the fuel divider and if the throttle body is not open, then = the fuel=20 is returned via the return line.  So in effect you are just pumping = fuel=20 back into the tanks via the return line.... Course like I said, I have = no=20 specific knowledge, just conjecture on how the fuel system works.  = I do=20 know tho that some people use the high boost mode to purge the vapor out = of the=20 lines after shutdown or before startup.  They simply allow the pump = to=20 circulate cool fuel throughout the lines, which is why I assume that the = injectors can only take a Max amount of fuel and the remainder is = shuttled back=20 to the tanks via return lines...
 
As I = also said, I wish=20 this wasn't all "black art" and that there was a scientific way to = determine the=20 optimal in all conditions...
Alan
From: Lancair Mailing List=20 [mailto:lml@lancaironline.net] On Behalf Of=20 marv@lancair.net
Sent: Monday, June 11, 2007 9:13 = PM
To:=20 lml@lancaironline.net
Subject: [LML] Re: Boost=20 switch

Posted for "Colyn Case = on=20 earthlink" <colyncase@earthlink.net>:

Alan,
I suspect = high boost=20 + a working mechanical pump on TO would be fairly
suicidal but I = can't say=20 that from experience. (hmmmm......)

Colyn
 

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