X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-la0-f47.google.com ([209.85.215.47] verified) by logan.com (CommuniGate Pro SMTP 6.0.5) with ESMTPS id 6362989 for flyrotary@lancaironline.net; Sat, 06 Jul 2013 15:37:36 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.47; envelope-from=wdleonard@gmail.com Received: by mail-la0-f47.google.com with SMTP id fe20so2839542lab.20 for ; Sat, 06 Jul 2013 12:36:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=AtpSi9dUNeyjUxdwlvuL46Q+VrVHuz463nqM9DJER9w=; b=Fs32F0jqylbDQoA3fb+3Ebpfx2zR9Z+Ygyg+8oprKM9ZT6S8k/IL1Lid/BRbSyqMzC cBsQpnov1KysjrSxCZGbCmkkq01mYozDrP9RsngYANkhl25OJVA/PUzDoxSHqcFuU60K CGEsFEOpvfZIkg+vM/kx0/TrtWkXYDk8zhgj7SMUxmyUAWoFGryyye1Ckgs3igzojRnY na2npKtIiEiTA2lTM9HRnML/nHN1MeVraUpKEMSFrScPVfeSOna4baD0F7uHVnxYKP1Z IsL+rS8kKxHy74n6LZqLDLjwK3NtL/Qwq5X5IHZQSllXQ3e+MOZm/a9EmYvr48OSuYec Ciaw== MIME-Version: 1.0 X-Received: by 10.152.27.40 with SMTP id q8mr7323038lag.75.1373139419279; Sat, 06 Jul 2013 12:36:59 -0700 (PDT) Received: by 10.112.60.70 with HTTP; Sat, 6 Jul 2013 12:36:59 -0700 (PDT) In-Reply-To: References: Date: Sat, 6 Jul 2013 12:36:59 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Turbo boost indication From: David Leonard To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=089e0158c5aa50376304e0dcef6d --089e0158c5aa50376304e0dcef6d Content-Type: text/plain; charset=ISO-8859-1 OK, so the more accurate conversion is 20psi=40.7 in Hg so in your example 20psi boost = 70.6 in MAP (Manifold Absolute Pressure) It help in your article, turbos work as a boost ratio. So this turbo it then making a boost ratio of: 70.6 / 29.9 = 2.36 So as you go up in altitude you multiply the ambient pressure by 2.36 So at 17,500 ft the pressure is half, and so is the MAP, or, 35.3 " MAP Losses are not porportunately reduced, and the turbo may be less efficient in that range so actual MAP may be less. On Sat, Jul 6, 2013 at 11:57 AM, Patrick Panzera wrote: > I'm editing an article about a bone stock, turbocharged direct injection > car engine that boasts 20 lbs of boost. > > I want to convert that to MP so us airplane junkies can wrap our heads > around it. > > Thanks! > > Pat > > > On Sat, Jul 6, 2013 at 11:44 AM, David Leonard wrote: > >> Simply convert 20 psi to Inches of Hg (its about 2 to 1 but not exactly) >> and add it to 29.9. So the MP should be about 69 inches, give or take >> depending on losses and where in the system you measure. >> >> I keep my plane less that 45 inches MP. You have to be more rich and >> skilled than me to go higher without detonation. >> >> >> On Sat, Jul 6, 2013 at 11:14 AM, Patrick Panzera < >> editor@contactmagazine.com> wrote: >> >>> Friends, >>> >>> Hypothetical question. >>> Let's say it's a standard day and I'm at sea level. >>> I've installed a turbocharger and have also connected the stock >>> automobile turbo boost gauge, along with my traditional manifold pressure >>> gauge. >>> >>> I ground-run the engine to full throttle (where the MP would normally be >>> reading 29.92- minus some efficiency loss) and the boost gauge is reading >>> 20 psi. >>> >>> What should the MP indicator be reading? >>> >>> Thanks! >>> >>> Pat >>> >>> >> >> >> -- >> David Leonard >> >> Turbo Rotary RV-6 N4VY >> http://N4VY.RotaryRoster.net >> http://RotaryRoster.net >> > > -- David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net --089e0158c5aa50376304e0dcef6d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
OK, so the more accurate conversion is=A0
20psi=3D40.7= in Hg
so in your example
20psi boost =3D 70.6 in MAP (= Manifold Absolute Pressure)

It help in your articl= e, turbos work as a boost ratio. =A0So this turbo it then making a boost ra= tio of:
70.6 / 29.9 =A0=3D 2.36

So as you go up in al= titude you multiply the ambient pressure by 2.36

S= o at 17,500 ft the pressure is half, and so is the MAP, or, 35.3 " MAP=

Losses are not porportunately reduced, and the turbo ma= y be less efficient in that range so actual MAP may be less.

=



On Sat, Jul 6, 2013 at 11:57 AM, Patrick Panzera <editor@contactm= agazine.com> wrote:
I'm editing an article about a bone stock, turbocharge= d direct injection car engine that boasts 20 lbs of boost.

I w= ant to convert that to MP so us airplane junkies can wrap our heads around = it.

Thanks!

Pat=A0


On Sat, Jul 6, 2013 at 11:44 AM, David Leonard <w= dleonard@gmail.com> wrote:
Simply convert 20 psi to In= ches of Hg (its about 2 to 1 but not exactly) and add it to 29.9. =A0So the= MP should be about 69 inches, give or take depending on losses and where i= n the system you measure.

I keep my plane less that 45 inches MP. =A0You have to be more r= ich and skilled than me to go higher without detonation.


On Sat, Jul 6, 2013 = at 11:14 AM, Patrick Panzera <editor@contactmagazine.com><= /span> wrote:
Friends,

Hypot= hetical question.=A0
Let's say it's a standard day and I&= #39;m at sea level.
I've installed a turbocharger and have also connected the stock au= tomobile turbo boost gauge, along with my traditional manifold pressure gau= ge.

I ground-run the engine to full throttle (where the MP = would normally be reading 29.92- minus some efficiency loss) and the boost = gauge is reading 20 psi.

What should the MP indica= tor be reading?

Thanks!

Pat




--
David Leonard

Turbo Rotary RV-6 N4VY=
http://N4VY.= RotaryRoster.net
http://RotaryRoster.n= et




--
= David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net --089e0158c5aa50376304e0dcef6d--