Return-Path: Received: from [65.54.169.115] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2b2) with ESMTP id 3184970 for flyrotary@lancaironline.net; Thu, 22 Apr 2004 15:01:30 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Thu, 22 Apr 2004 12:01:29 -0700 Received: from 4.174.6.233 by BAY3-DAV85.phx.gbl with DAV; Thu, 22 Apr 2004 19:01:29 +0000 X-Originating-IP: [4.174.6.233] 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: Thu, 22 Apr 2004 15:01:28 -0400 MIME-Version: 1.0 X-Mailer: MSN Explorer 7.02.0011.2700 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0002_01C4287A.B0308EF0" Message-ID: X-OriginalArrivalTime: 22 Apr 2004 19:01:29.0442 (UTC) FILETIME=[38197C20:01C4289C] ------=_NextPart_001_0002_01C4287A.B0308EF0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable =20 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. =20 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. =20 Tracy =20 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. =20 Where do you measure MAP on your system? I can=C3=A2=E2=82=AC=E2=84=A2t = believe that you could see that kind of pressure at the engine end of a l= ong intake tube. But I remember once before when I was wrongJ. =20 Al =20 I measure it at the dynamic/plenum chamber, just under the throttle body.= =20 Tracy =20 Hum-m-m. That=C3=A2=E2=82=AC=E2=84=A2s about equivalent to me measuring= it in the air plenum before the TB. It would be very interesting to kno= w what it is on yours about 4=C3=A2=E2=82=AC=C2=9D from the intake port. = Then there is the whole question of =C3=A2=E2=82=AC=CB=9Cwhich=C3=A2=E2=82= =AC=E2=84=A2 MAP pressure the EC-2 should be interpreting =E2=80=93 or ma= ybe it doesn=C3=A2=E2=82=AC=E2=84=A2t matter. . . =20 Al =20 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 ). =20 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 : ) =20 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. =20 Tracy Tracy, So, where's the correct location for the MAP port? =20 Mark S. =20 Go up 6 paragraphs and read it again : ) Tracy ------=_NextPart_001_0002_01C4287A.B0308EF0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

<= DIV>

=

One more c= omment on intake manifolds & race results.   Do not ignore = the benefits of a really clean air inlet with ram air recovery BEFORE the= manifold.   At 1125 ft msl, 220 IAS, I saw manifold pres= sures around 31.8" Hg. Ignore this factor and you throw away about = 6% "free" horsepower.

&= nbsp;
Al, I forgot to comment on your last note about your MAP = tap in manifold. I think it is highly possible you were seeing erro= rs induced by air stream eddies or some other unpredictable factors cause= d 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 po= rts in the TWM throttle body. I assumed they would know where to pl= ace the port to get a good measurement.
Where do you measure MAP on your system? I c= an=C3=A2=E2=82=AC=E2=84=A2t believe that you could see that kind of press= ure at the engine end of a long intake tube. But I remember once be= fore when I was wrongJ.
Al
I measure it at the dynamic/plenum chamber= , just under the throttle body.
Tracy
Hum-m-m.=    That=C3=A2=E2=82=AC=E2=84=A2s about equivalent to me measuri= ng it in the air plenum before the TB. It would be very interesting= to know what it is on yours about 4=C3=A2=E2=82=AC=C2=9D from the intake= port. Then there is the whole question of =C3=A2=E2=82=AC=CB=9Cwhi= ch=C3=A2=E2=82=AC=E2=84=A2 MAP pressure the EC-2 should be interpreting =E2= =80=93 or maybe it doesn=C3=A2=E2=82=AC=E2=84=A2t matter. . .
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 matter to the EC2 if you tried to measure MAP there (i.= e., Would Not Work ).

At one time I did measure the MAP at the far end = of the small (primary) runners and found a .8" Hg drop at WOT compared to= dynamic chamber reading. I expected this drop. For reasons o= f not wanting to enter a prolonged and fruitless discussion on rotary eng= ine 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 ram air re= covery (at ~200 mph), REGARDLESS OF WHERE you measure it. <= DD>

Tracy<= /DD>

Tracy,
So, where's the correct loc= ation for the MAP port?

Mark S.

Go up 6 paragr= aphs and read it again : )

Tracy

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