Return-Path: Received: from [65.54.169.130] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2b2) with ESMTP id 3182731 for flyrotary@lancaironline.net; Wed, 21 Apr 2004 11:52:38 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 21 Apr 2004 08:52:38 -0700 Received: from 4.174.0.254 by BAY3-DAV100.phx.gbl with DAV; Wed, 21 Apr 2004 15:52:38 +0000 X-Originating-IP: [4.174.0.254] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: intake ideas? Date: Wed, 21 Apr 2004 11:52:36 -0400 MIME-Version: 1.0 X-Mailer: MSN Explorer 7.02.0011.2700 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0002_01C42797.237FCEA0" Message-ID: X-OriginalArrivalTime: 21 Apr 2004 15:52:38.0578 (UTC) FILETIME=[ABF71920:01C427B8] ------=_NextPart_001_0002_01C42797.237FCEA0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable One more comment on intake manifolds & race results. Do not ignore the = benefits of a really clean air inlet with ram air recovery BEFORE the man= ifold. At 1125 ft msl, 220 IAS, I saw manifold pressures around 31.8" = Hg. Ignore this factor and you throw away about 6% "free" horsepower. Al, I forgot to comment on your last note about your MAP tap in manifold= I think it is highly possible you were seeing errors induced by air st= ream eddies or some other unpredictable factors caused by that location. = It is a challenge to get MAP measurements when you have no real plenum,= only runners with high velocity air. Tracy I use the stock ports in the TWM throttle body. I assumed they would kno= w where to place the port to get a good measurement. Where do you measure MAP on your system? I can=E2=80=99t believe that yo= u could see that kind of pressure at the engine end of a long intake tube= But I remember once before when I was wrongJ. Al I measure it at the dynamic/plenum chamber, just under the throttle body. Tracy Hum-m-m. That=E2=80=99s about equivalent to me measuring it in the air = plenum before the TB. It would be very interesting to know what it is on= yours about 4=E2=80=9D from the intake port. Then there is the whole qu= estion of =E2=80=98which=E2=80=99 MAP pressure the EC-2 should be interpr= eting =E2=80=93 or maybe it doesn=E2=80=99t matter. . . =20 Al Before the TB? I don't follow you. Ideally, that would be true at WOT = only, but it would be a fairly useless figure. And it would definitely m= atter to the EC2 if you tried to measure MAP there (i.e., Would Not Wor= k ). At one time I did measure the MAP at the far end of the small (primary) r= unners and found a .8" Hg drop at WOT compared to dynamic chamber reading= I expected this drop. For reasons of not wanting to enter a prolonged= and fruitless discussion on rotary engine manifold design, I will not ex= plain why this drop is desirable : ) But my main point was that you can get about 2" of MAP increase from ram = air recovery (at ~200 mph), REGARDLESS OF WHERE you measure it. Tracy ------=_NextPart_001_0002_01C42797.237FCEA0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

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One mor= e comment on intake manifolds & race results.   Do not igno= re the benefits of a really clean air inlet with ram air recovery BEFORE = the manifold.   At 1125 ft  msl, 220 IAS, I saw manif= old pressures around 31.8" Hg. Ignore this factor and you throw awa= y about 6% "free" horsepower.

Al, I= forgot to comment on your last note about your MAP tap in manifold. = ; I think it is highly possible you were seeing errors induced by air str= eam eddies or some other unpredictable factors caused by that location.&n= bsp; It is a challenge to get MAP measurements when you have n= o real plenum, only runners with high velocity air.

Tracy

I use the stock ports i= n the TWM throttle body. I assumed they would know where to place t= he port to get a good measurement.

= Where = do you measure MAP on your system? I can=E2=80=99t believe that you= could see that kind of pressure at the engine end of a long intake tube.= But I remember once before when I was wrongJ.

Al

I measure it at the dynamic/plenum chamber, just under the throttl= e body.

Tracy

Hum-m-m. Tha= t=E2=80=99s about equivalent to me measuring it in the air plenum before = the TB. It would be very interesting to know what it is on yours ab= out 4=E2=80=9D from the intake port. Then there is the whole questi= on of =E2=80=98which=E2=80=99 MAP pressure the EC-2 should be interpretin= g =E2=80=93 or maybe it doesn=E2=80=99t matter. . .
Al

&nbs= p;

Before the TB?&nb= sp; I don't follow you. Ideally, that would be true at WOT on= ly, but it would be a fairly useless figure. And it would definitel= y matter to the EC2 if you tried to measure MAP there (i.e., &= nbsp;Would Not Work ).

At one time I did measure the MAP at the far end o= f the small (primary) runners and found a .8" Hg drop at WOT compared to = dynamic chamber reading. I expected this drop.  For reaso= ns of not wanting to enter a prolonged and fruitless discussion on rotary= engine manifold design, I will not explain why this drop is desirable : = )

But= my main point was that you can get about 2" of MAP increase from ra= m air recovery (at ~200 mph),  REGARDLESS OF WHERE yo= u measure it.

Tracy
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