X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.219.56.245] (HELO mail.qnsi.net) by logan.com (CommuniGate Pro SMTP 6.0.8) with ESMTP id 6750291 for flyrotary@lancaironline.net; Wed, 26 Feb 2014 10:11:35 -0500 Received-SPF: none receiver=logan.com; client-ip=66.219.56.245; envelope-from=bhughes@qnsi.net X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message Return-Receipt-To: "Bobby J. Hughes" Subject: RE: [FlyRotary] Re: wastegate control and oil coolers MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01CF3304.F4D48545" Disposition-Notification-To: "Bobby J. Hughes" Date: Wed, 26 Feb 2014 09:10:59 -0600 Message-ID: <74120FDE88CAFE4DBDA8814BCE20A3F36262AE@qnsi-mail.qnsi.net> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: wastegate control and oil coolers Thread-Index: Ac8zBLlD+lqPz4oeRim+qm8mp+DIqw== From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01CF3304.F4D48545 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Steve, =20 The operating range may be wide enough to work for my planned turbo swap. I would like to control 30"MP \ 5# at 10K with engine rpm at 4800. Limit takeoff to 38"MP \ 4# at 7000 rpm. And operate between ambient pressure and 28" MP when desired without closing the throttle. I like to cruise with WOT between 4800 and 5200 rpm, F/A around 15.8 at less than 28"MP. This allows EGT's between 1480-1525F depending on altitude and MP.=20 =20 Any pictures you could share? =20 Bobby=20 =20 =20 =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese Sent: Wednesday, February 26, 2014 2:42 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: wastegate control and oil coolers =20 Bobby, =20 I believe the behavior you are describing would be for an absolute pressure controller (not variable). =20 The variable absolute pressure controller allows a moving target. The way the one I have is adjusted, the minimum setting of the variable function is set at 28" Hg and is referenced to the duct between the compressor and throttle body. The wastegate is closed at pressures less than 28". Advancing the throttle enables the turbo to eventually develop pressure which is initially limited to 28" Hg upstream of the throttle body by the controller modulating the wastegate. So MAP is controlled by the throttle up to that 28" Hg. With normal atmospheric pressure here of 23" Hg at 7200 ft elevation, WOT would only give a MAP of 23" Hg without the turbo. With the throttle open and MAP at 28" Hg, the variable function of the controller can then be actuated with a separate control cable and used to raise the MAP above 28" Hg. The maximum attainable MAP is determined by the adjustment of the controller or the capability of the turbo. =20 =20 With my equipment, there is still throttle movement available when 28" Hg is reached (the throttle body is larger than necessary) so the throttle body linkage could be also directly connected to the controller instead of using a separate control cable. That way the single throttle control would enable setting the MAP from idle to the maximum allowed by the controller. I don't know what the upper limit of MAP is since 36" Hg is the highest setting I've tried. My intent is just to normalize MAP to sea level. =20 With this control mechanism, above 28" Hg the turbo is only producing the amount of boost required by the throttle setting rather than producing excess boost which is then reduced by throttle body. The result is a minimum of exhaust back pressure and better efficiency. =20 The absolute pressure reference aneroid in the controller enables the controller to maintain the MAP setting independent of changes in altitude. =20 Steve =20 =20 =20 ________________________________ =20 =20 From: Rotary motors in aircraft > on behalf of Bobby J. Hughes > Sent: Tuesday, February 25, 2014 3:18 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: wastegate control and oil coolers=20 =20 Steve I think I understand now. You set the maximum \ target MP and use the throttle to operate below the target when desired.=20 Bobby Sent from my iPad =20 =20 ------_=_NextPart_001_01CF3304.F4D48545 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Steve,

 

The operating range may be wide enough to work for my planned turbo = swap. I would like to control 30”MP \ 5# at 10K with engine rpm at = 4800. Limit takeoff to 38”MP \ 4# at 7000 rpm. And operate between = ambient pressure and 28” MP when desired without closing the = throttle.  I like to cruise with WOT between 4800 and 5200 rpm, F/A = around 15.8 at less than 28”MP. This allows EGT’s between = 1480-1525F depending on altitude and MP.

 

Any pictures you could share?

 

Bobby

 

 

 

From:= = Rotary motors in aircraft [mailto:flyrotary@lancaironlin= e.net] On Behalf Of Steven W. Boese
Sent: = Wednesday, February 26, 2014 2:42 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: wastegate control and oil = coolers

 

Bobby,

 

I believe the = behavior you are describing would be for an absolute pressure controller = (not variable).

 

The variable = absolute pressure controller allows a moving target.  The way the = one I have is adjusted, the minimum setting of the variable function is = set at 28" Hg and is referenced to the duct between the compressor = and throttle body.  The wastegate is closed at pressures less than = 28".  Advancing the throttle enables the turbo to = eventually develop pressure which is initially limited to 28" = Hg upstream of the throttle body by the controller modulating the = wastegate.  So MAP is controlled by the throttle up to that = 28" Hg.  With normal atmospheric pressure here of 23" Hg = at 7200 ft elevation, WOT would only give a MAP of 23" Hg without = the turbo.  With the throttle open and MAP at 28" Hg, the = variable function of the controller can then be actuated with a = separate control cable and used to raise the MAP above 28" = Hg.  The maximum attainable MAP is determined by = the adjustment of the controller or the capability of the = turbo. 

 

With my = equipment, there is still throttle movement available when 28" = Hg is reached (the throttle body is larger than necessary) = so the throttle body linkage could be also directly = connected to the controller instead of using a separate control = cable.  That way the single throttle control would enable setting = the MAP from idle to the maximum allowed by the controller.  I = don't know what the upper limit of MAP is since 36" Hg is the = highest setting I've tried.  My intent is just to normalize MAP to = sea level.

 

With this = control mechanism, above 28" Hg the turbo is only producing = the amount of boost required by the throttle setting rather than = producing excess boost which is then reduced by throttle = body.  The result is a minimum of exhaust back pressure and = better efficiency.

 

The absolute = pressure reference aneroid in the controller enables the controller to = maintain the MAP setting independent of changes in = altitude.

 

Steve=

  &nbs= p;  

 

 

 

 

From: Rotary motors in aircraft <flyrotary@l= ancaironline.net> on behalf of Bobby J. Hughes <bhughes@qns= i.net>
Sent: Tuesday, February 25, 2014 3:18 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: wastegate = control and oil coolers =

 

Steve


I think I = understand now. You set the maximum \ target MP and use the throttle to = operate below the target when = desired. 


Bobby
<= br>Sent from my iPad

 

 

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