X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fk-out-0910.google.com ([209.85.128.189] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2336767 for flyrotary@lancaironline.net; Mon, 17 Sep 2007 22:53:36 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.128.189; envelope-from=wdleonard@gmail.com Received: by fk-out-0910.google.com with SMTP id b27so1833640fka for ; Mon, 17 Sep 2007 19:53:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; bh=LFADW5iCdtGgMpSj/xBagAViybdhDfMNlv9tjnXysww=; b=Ntzx99SAsfnk/g/8NRLMeuO/uSINeorfL+imP29kNIfEpRFPAf9cBfW0Pw1PvuEw8z4WYzRXY1+nflG0DeT8KNzl7XLH4ukGt10v1e6TvDlAEE2m3sADKVYW6GoLTYywVwnYR5jITbqN3+74WevJVddA/Gr2Jg7g7lIzJqHuaX0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=ZCj3yUiKXBLCFu5BnIcJwgN3rTrh/W9LiauRTZ3cBbfhPpg+GnOhyZQupYSZjVvmCoyHoOAk0SOBOUMufBt75m61pM0/gGTv0ueEWDHm/CPGvzCPKjJd9uNmqpo1OdUT1jp3qwjsafVrNd/nwclXx2JuIaiTBJu9wzZ4s8qBt2k= Received: by 10.82.189.6 with SMTP id m6mr5890424buf.1190083978922; Mon, 17 Sep 2007 19:52:58 -0700 (PDT) Received: by 10.82.122.16 with HTTP; Mon, 17 Sep 2007 19:52:58 -0700 (PDT) Message-ID: <1c23473f0709171952v2ec4b613o908b7915f85508fd@mail.gmail.com> Date: Mon, 17 Sep 2007 19:52:58 -0700 From: "David Leonard" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] One for the guys that don't give up In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_14252_30713591.1190083978893" References: ------=_Part_14252_30713591.1190083978893 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Al, I have the TWM at the end of long runners, and computer B takes its manifol= d reading there. I also use the stock manifold that has a port right as the mixture enters the center housing. Computer A takes its manifold reading there. Besides a slight difference in the mixture necessary between the 2 computers, both locations seem to work well. Sorry I don't have a solution. Dave Leonard On 9/17/07, Al Gietzen wrote: > > > I don't seldom give up on a problem, but I came awfully close this time. > > Mark > > OK; Mark; (or anybody). Since we both have 20Bs, and both use the EC2 > controller, maybe you have a clue for this one. I've brought this up here > before, but no solution. > > I have all the latest updates on the EC2, and I have double checked the > static timing set at 35o BTDC. From that point on the EC2 is handling th= e > timing curve with rpm and MAP. > > At lower power levels, disabling the leading ignition clearly has a large= r > effect than disabling the trailing =96 as one would expect. At somewhere > around 18" MAP, (don't know right now what rpm that is, maybe close to 40= 00) > the effect is about equal when disabling either set. At higher power > levels, there is a larger effect of disabling the trailing than the > leading. That troubles me. I think the leading should always have a > greater effect. It makes me wonder about the timing; or if something els= e > is wrong. > > I have in the past tried varying the timing 2 or 3 steps while at power, > but couldn't discern a change in rpm greater than the normal variation in > the readout. Tracy sent me the XL spreadsheet with the timing curve data= , > but I haven't yet figured a safe way of checking it with that prop spinni= ng > close by. > > Does your installation exhibit the same behavior? Is there some > explanation for this? What test should I perform? > > One thing that occurs to me is that Tracy measures MAP out before the > runners. I measure MAP at the manifold, downstream from intake plenum an= d > three short runners and the 3-barrel TWM throttle body. At WOT my MAP is > not atmospheric pressure =96 it is maybe 2-3" HG less. I can't quite see= how > that is an issue; but maybe someone else with a TWM TB setup with the MAP > port downstream would know. > > > > Other than that I'm very pleased with the new mixture correction table > setup for the 20B. Much less tuning and seamless transistion between tab= les > and through the stage point. Probably the pulse clamping and injector > isolation diodes are part of that. > --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net ------=_Part_14252_30713591.1190083978893 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Al,

I have the TWM at the end of long runners, and computer B takes = its manifold reading there.  I also use the stock manifold that has a = port right as the mixture enters the center housing.  Computer A takes= its manifold reading there.  Besides a slight difference in the mixtu= re necessary between the 2 computers, both locations seem to work well.

Sorry I don't have a solution.

Dave Leonard

= On 9/17/07, Al Gi= etzen <ALVentures@cox.net&= gt; wrote:

I don't seldom give up on a problem, but I came awfully close this time= .

Mark

OK; Mark; (or anybody).  Since we both have 20Bs, and both use the EC2 controller, maybe you h= ave a clue for this one. I've brought this up here before, but no solution.

I have all the latest updates = on the EC2, and I have double checked the static timing set at 35o BTDC= .  From that point on the EC2 is handling the timing curve with rpm and MAP.

At lower power levels, disabli= ng the leading ignition clearly has a larger effect than disabling the trailing = =96 as one would expect.  At somewhere around 18" MAP, (don't know right now what rpm that is, maybe close to 4000) the effect is about equal = when disabling either set.  At higher power levels, there is a larger effec= t of disabling the trailing than the leading.  That troubles me.  I th= ink the leading should always have a greater effect.  It makes me wonder a= bout the timing; or if something else is wrong.

I have in the past tried varyi= ng the timing 2 or 3 steps while at power, but couldn't discern a change in rpm gr= eater than the normal variation in the readout.  Tracy sent m= e the XL spreadsheet with the timing curve data, but I haven't yet figured a safe way of checking it with that prop spinning close by.

Does your installation exhibit= the same behavior? = ; Is there some explanation for this?  What test should I perform?

One thing that occurs to me is= that Tracy measures MAP = out before the runners.  I measure MAP at the manifold, downstream from in= take plenum and three short runners and the 3-barrel TWM throttle body.  At= WOT my MAP is not atmospheric pressure =96 it is maybe 2-3" HG less.  I can't quite see how that is an issue; but maybe someone else with a TWM TB setup with the MAP port downstream would know.

 

Other than that I'm very pleas= ed with the new mixture correction table setup for the 20B.  Much less tuning = and seamless transistion between tables and through the stage point.  Prob= ably the pulse clamping and injector isolation diodes are part of that.




--
David Leonard

Tu= rbo Rotary RV-6 N4VY
http://N4V= Y.RotaryRoster.net
http://Rotary= Roster.net ------=_Part_14252_30713591.1190083978893--