Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Thu, 27 Mar 2003 18:50:33 -0500 Message-ID: X-Original-Return-Path: <13brv3@mchsi.com> Received: from sccmmhc01.mchsi.com ([204.127.203.183] verified) by logan.com (CommuniGate Pro SMTP 4.1b1) with ESMTP id 2088379 for flyrotary@lancaironline.net; Thu, 27 Mar 2003 11:41:54 -0500 Received: from rad (12-218-74-116.client.mchsi.com[12.218.74.116]) by sccmmhc01.mchsi.com (sccmmhc01) with SMTP id <20030327164153mm100sthafe>; Thu, 27 Mar 2003 16:41:53 +0000 Reply-To: <13brv3@mchsi.com> From: <13brv3@mchsi.com> X-Original-To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: boost control? X-Original-Date: Thu, 27 Mar 2003 10:41:46 -0600 X-Original-Message-ID: <000001c2f47f$c502e380$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C2F44D.7A687380" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C2F44D.7A687380 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I had intended to see if the wastegate could be eliminated entirely, and control boost strictly with throttle adjustments, ie if the engine is running at low power ,Idle, the throttle is almost closed thus eliminating the amount of fuel mixture burned thereby controlling exhaust gas pressure and controlling turbo speed. On takeoff, you would not use full throttle and the restriction at the throttle body would reduce boost in the same way. I think you would quickly learn about how much throttle to use and make needed adjustments after becoming airborn. --- This will certainly work, but you will still want a pop-off valve for those times that you misjudge the throttle movement. There are also times when a sudden go around may be required. This wouldn't be the best time to have to manually judge how far to push the lever. I'm not sure how much simpler it can get than a manual wastegate cable and a pop-off valve. However, I have purchased a standard exhaust manifold and it looks like the wastegate would have to be cut out and the hole welded shut so I quess since it's already there I'm going to put a manual control on it. --- What year is that manifold from? You're not running 3rd gen twins are you? The reason I ask, is that I don't think any 2nd gen manifolds had a wastegate built-in. Mine is the 89-91 version, and the wastegate is in the turbo itself. The exhaust manifold has no valves at all. I believe the 87-88 version had some sort of diverter valve, that was supposed to help spool quicker, but I've never seen one, do I'm not sure where it was located. Just curious. Rusty ------=_NextPart_000_0001_01C2F44D.7A687380 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

I had intended to see
if the wastegate could be = eliminated=20 entirely, and
control boost strictly with throttle adjustments, = ie
if the=20 engine is running at low power ,Idle, the
throttle is almost closed = thus=20 eliminating the amount
of fuel mixture burned thereby controlling = exhaust=20 gas
pressure and controlling turbo speed. On takeoff, you
would = not use=20 full throttle and the restriction at the
throttle body would reduce = boost in=20 the same way. I
think you would quickly learn about how much = throttle
to=20 use and make needed adjustments after becoming
airborn.

--- This = will certainly=20 work, but you will still want a pop-off valve for those times that you = misjudge=20 the throttle movement.  There are also times when a sudden go = around may be=20 required.  This wouldn't be the best time to have to manually judge = how far=20 to push the lever.  I'm not sure how much simpler it can get than a = manual=20 wastegate cable and a pop-off valve. 

 However, I have purchased a standard exhaust
manifold and it = looks=20 like the wastegate would have to
be cut out and the hole welded shut = so I=20 quess since
it's already there I'm going to put a manual = control
on it.=20

--- What year is that = manifold=20 from?  You're not running 3rd gen twins are you?  The reason I = ask, is=20 that I don't think any 2nd gen manifolds had a wastegate built-in.  = Mine is=20 the 89-91 version, and the wastegate is in the turbo itself.  The = exhaust=20 manifold has no valves at all.  I believe the 87-88 version had = some sort=20 of diverter valve, that was supposed to help spool quicker, but I've = never seen=20 one, do I'm not sure where it was located.   Just = curious.

Rusty

 

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