Return-Path: <13brv3@bellsouth.net> Received: from imf17aec.mail.bellsouth.net ([205.152.59.65] verified) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2624563 for flyrotary@lancaironline.net; Sun, 05 Oct 2003 00:06:08 -0400 Received: from rad ([68.212.15.208]) by imf17aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20031005040612.TYCV1821.imf17aec.mail.bellsouth.net@rad> for ; Sun, 5 Oct 2003 00:06:12 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: max boost with wastegate open Date: Sat, 4 Oct 2003 23:06:09 -0500 Message-ID: <019601c38af6$023ce900$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0197_01C38ACC.1966E100" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0197_01C38ACC.1966E100 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable > I'm absolutely convinced that 5 psi will be much stronger when I can > get the wastegate opened up more I missed something here. Could you explain this a little? Why does the wastegate need to be bigger? =20 The simple answer is, when I open the throttle on takeoff, I only want 5 = psi of pressure. As it is now, if I open the throttle, with the wastegate = fully open, I get 10 psi. The wastegate just isn't big enough. =20 =20 The more complicated, and controversial answer is that pressure isn't everything. In a static condition, all that matters is the pressure. = In a dynamic condition, where there's a large amount of flow through the = intake, any restriction will cause a loss of power. In my current = configuration, I have to run about half throttle to stay below 5 psi. That means that = the butterflies are half closed, and are a pretty significant restriction to airflow. We know that engines are at their most efficient mode when the throttle is wide open, and this is no exception. =20 =20 Step one, is getting the throttle fully open. In order to do this, you = need to be able to control the boost pressure, and that goes back to the wastegate size. I'm convinced that I'll have significantly more power = at 5 psi, with the throttle fully open, than I do now with the throttle half closed. =20 =20 If I were an optimist, I'd say that all these problems are good, because = I can look forward to improvements every weekend. Pity I'm a pessimist = :-) > I had recently re-oriented the oil vent line Hmmm. Oil vent line? I don't think I have one. Where does that connect? There should be a vent line on the oil filler tube, or on the center = housing near the tube. You don't want to plug these up. =20 Rusty=20 ------=_NextPart_000_0197_01C38ACC.1966E100 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message

> I’m absolutely convinced that 5 psi will be = much stronger=20 when I can
> get the wastegate opened up more
I missed = something here.=20 Could you explain this a little? Why does the wastegate need to be=20 bigger?

 
The = simple answer is,=20 when I open the throttle on takeoff, I only want 5 psi of = pressure.  As it=20 is now, if I open the throttle, with the wastegate fully open, I = get 10=20 psi.  The wastegate just isn't big = enough.  
 
The more = complicated,=20 and controversial answer is that pressure isn't everything.  In a = static=20 condition, all that matters is the pressure.  In a dynamic=20 condition, where there's a large amount of flow through the intake, = any=20 restriction will cause a loss of power.  In my current = configuration, I=20 have to run about half throttle to stay below 5 psi.   That = means that=20 the butterflies are half closed, and are a pretty significant = restriction to=20 airflow.  We know that engines are at their most efficient mode = when the=20 throttle is wide open, and this is no = exception.  
 
Step = one, is getting the=20 throttle fully open.  In order to do this, you need to be able to = control=20 the boost pressure, and that goes back to the wastegate size.  = I'm=20 convinced that I'll have significantly more power at 5 psi, with=20 the throttle fully open, than I do now with the throttle half=20 closed.  
 
If I = were an optimist,=20 I'd say that all these problems are good, because I can look = forward=20 to improvements every weekend.  Pity I'm a pessimist=20 :-)   

> I had recently re-oriented the oil vent line
Hmmm. Oil vent = line? I=20 don't think I have one. Where does that connect?

There should be a vent = line on the oil=20 filler tube, or on the center housing near the tube.  You don't = want=20 to plug these up. 

Rusty

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