Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 794195 for flyrotary@lancaironline.net; Tue, 15 Mar 2005 07:13:27 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.101; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-185-127.carolina.rr.com [24.74.185.127]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j2FCCd0W029392 for ; Tue, 15 Mar 2005 07:12:40 -0500 (EST) Message-ID: <001a01c52958$4a61c730$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: SAG Report Date: Tue, 15 Mar 2005 07:12:42 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0017_01C5292E.6159B2B0" 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 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0017_01C5292E.6159B2B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hard to say, John. I have had surges both ways but they were mainly due = to the fact my fuel map is somewhat uneven. So changes in rpm or = manifold pressure change the operational area to a point in the map = where it either gets an enrichment (more power) or a leaning (less = power). Also, when an SAG event clears up you certainly get a surge as = the rotors starts producing normal power again. If you hit a "rich" spot in the fuel map, it would cause an increase in = power, an increase in RPM, but not certain why it would cause a drop in = manifold pressure - unless the higher rpms happened quickly enough = (sucked the manifold pressure down) before the turbine wheel and = compressor caught up. However, If you are using the EM2 to tailor your = EC2 Fuel map then less likelihood of unevenness in the fuel map. But, if it were a sparkplug "clearing up" I would think the event would = be longer term. I don't know what the symptoms would be with SAG = underboost but if my speculation about the cause of SAG is correct, it = should be worst and last longer. Based on what I observed with oil and = coolant temps while under SAG, I would think yours would be quite = elevated. If they are not - then doubtful you encountered SAG (yet). So really don't have a better SWAG about what you may have encountered, = but can understand you wanting to find that "sweet" spot again {:>) Ed A ----- Original Message -----=20 From: John Slade=20 To: Rotary motors in aircraft=20 Sent: Monday, March 14, 2005 10:19 PM Subject: [FlyRotary] Re: SAG Report Speaking of SAG, I had a strange experience during today's flight = which might be the opposite of SAG.=20 Everything seemed normal. I was boosting about 38 MAP at 4500 rpm and = 5000'. I was gently adding a little throttle to increase speed for = another ASI calibration when I felt a surge of acceleration way beyond = what I'd expect for the minor throttle adjustment I'd made. This was = literally a shove in the back. It lasted maybe 2 seconds, then the = engine carried on at the new power level. RPM jumped up a couple of = hundred. I glanced down at the MAP. It had dropped to 34. My best guess = is that I'd been running with a gummed up plug which suddenly cleared = and gave me added power. I'd appreciate any opinions on this. Now if I could just make it happen again - and again..... John (getting relaxed enough to test the airframe) ------=_NextPart_000_0017_01C5292E.6159B2B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hard to say, John.  I have had = surges both=20 ways but they were mainly due to the fact my fuel map is = somewhat=20 uneven.  So changes in rpm or manifold pressure change the = operational area=20 to a point in the map where it either gets an enrichment (more power) or = a=20 leaning (less power).  Also, when an SAG event clears up you = certainly get=20 a surge as the rotors starts producing normal power again.
 
If you hit a "rich" spot in the fuel = map, it would=20 cause an increase in power, an increase in RPM, but not certain why it = would=20 cause a drop in manifold pressure - unless the higher rpms = happened quickly=20 enough (sucked the manifold pressure down) before the turbine wheel = and=20 compressor caught up.  However,  If you are using the EM2 to = tailor=20 your EC2 Fuel map then less likelihood of unevenness in the fuel=20 map.
 
But, if it were a sparkplug "clearing = up" I would=20 think the event would be longer term.  I don't know what = the=20 symptoms would be with SAG underboost but if my speculation about the = cause of=20 SAG is correct, it should be worst and last longer.  Based on = what I=20 observed with oil and coolant temps while under SAG, I would think yours = would=20 be quite elevated.  If they are not - then doubtful you encountered = SAG=20 (yet).
 
So really don't have a better SWAG = about what you=20 may have encountered, but can understand you wanting to find that = "sweet" spot=20 again {:>)
 
Ed A
 
 
----- Original Message -----
From:=20 John=20 Slade
Sent: Monday, March 14, 2005 = 10:19=20 PM
Subject: [FlyRotary] Re: SAG = Report

Speaking of SAG, I had = a strange=20 experience during today's flight which might be the opposite of SAG.=20
 
Everything seemed normal. I was boosting about = 38 MAP=20 at 4500 rpm and 5000'. I = was gently adding a little throttle to = increase speed=20 for another ASI calibration when I felt a surge of acceleration way = beyond=20 what I'd expect for the minor throttle adjustment I'd made. This=20 was literally a shove in = the back.=20 It lasted maybe 2 seconds, then the engine carried on at the new power = level. RPM jumped up a couple of = hundred.=20 I glanced down at the MAP. It had dropped to 34. My best guess = is that=20 I'd been running with a gummed up plug which suddenly cleared and gave = me=20 added power.
 
I'd appreciate any = opinions on=20 this.
Now=20 if I could just make it happen again - and = again.....
 
John=20 (getting relaxed enough to test the=20 airframe)
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