Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2b1) with ESMTP id 3139779 for flyrotary@lancaironline.net; Thu, 01 Apr 2004 00:30:14 -0500 Received: from edward (clt25-78-058.carolina.rr.com [24.25.78.58]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i315UCkG006117 for ; Thu, 1 Apr 2004 00:30:13 -0500 (EST) Message-ID: <000801c417aa$6928b090$2402a8c0@edward> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: One more question : EC2 operation Date: Thu, 1 Apr 2004 00:30:14 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0005_01C41780.8014B530" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0005_01C41780.8014B530 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =20 Ok, one more time for us slow folks. I understand that the = EC2 calculations some "adjustment" to the fuel requirement for each = intake cycle. Since the intake cycle is certainly tied to rpm in so far = that the rpm determines the number of intake events per unit time. I = think I follow that each intake cycle can be different as far as fuel = requirement. I had assumed that the fuel injection adjusment is = primarily based on the manifold pressure it senses. In otherwords, if = the Ec2 senses 17" Hg manifold pressure at a specific intake manfiold = air temp it calculates X milleseconds of injection time. I had assumed = that this amount of injection time would be the same whether 17" at 3000 = rpm or 17" at 5000 rpm but that since the injector fires more times/sec = at 5000 rpm than 3000 rpm there would be more fuel injected. In = otherwords, I had assumed that since the EC2 does its calculation for = each cycle, it didn't know(orcare) whether the cydle was happening at = 3000 rpm or 5000 rpm only what the manifold pressure was at each rpm. Since my assumption is apparently incorrect, then over a beer, = you need to explain it to me one more time how the RPM is a factor in = the computation of fuel injection time. I strongly suspected that Ve wasn't really a factor for the = reasons you stated, too bad {:>) Ed Anderson I think semantics are confusing both of us (or me at least : = ). If we look at it in terms of a single intake cycle, rpm does not = figure into the equation. If you look at it in terms of CC per minute or = gallons per hour, it does. However, in the latest version of the = software (which Rusty has), rpm does have an effect in that a different = MAP table is used for high and low RPM ranges. =20 Tracy (who would never accuse Ed of being slow ! ) OK, Tracy, I agree about the semantics and the two points of = reference. Within terms of a single intake cycle rpm does not directly = figure into the fuel injection time calculation. However, it is = certainly a factor in terms of CC/Minute as there are more intake cycles = at 5000 rpm than 3000 rpm. So when I stated earlier that RPM was not a = computation factor in determining injector pulse width time, I did not = mean it was not a factor in determining how many CC/Gallons of fuel flow = were consumed. So if you consider that total injection time (and = therefore total fuel flow) is a product of injection time computed = (based on manifold pressure) AND number of times that injection cycle is = trigger per unit time (RPM), then I think we are on the same sheet of = music. RPM IS a factor in determining fuel flow, just not in = calculating injector pulse width. (I think). Thanks for the explanation (again {:>)). Ed Anderson ------=_NextPart_000_0005_01C41780.8014B530 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
 
 
 
Ok, one more time for = us slow=20 folks.  I understand that the EC2 calculations some = "adjustment"=20 to the fuel requirement for each intake cycle. Since the = intake cycle=20 is certainly tied to rpm in so far that the rpm determines the = number=20 of intake events per unit time.  I think I follow  = that each=20 intake cycle can be different as far as fuel = requirement.  =20 I had  assumed that the fuel injection adjusment is = primarily=20 based on the manifold pressure it senses.  In otherwords, = if the=20 Ec2 senses 17" Hg manifold pressure at a specific intake = manfiold=20 air temp it calculates X milleseconds of injection time.  = I had=20 assumed that this amount of injection time would be the = same=20 whether 17" at 3000 rpm or 17" at 5000 rpm but that since = the=20 injector fires more times/sec at 5000 rpm than 3000 rpm there = would be=20 more fuel injected.   In otherwords, I had assumed = that=20 since the EC2 does its calculation for each cycle, it didn't=20 know(orcare) whether the cydle was happening at 3000 rpm or = 5000 rpm=20 only what the manifold pressure was at each rpm.
 
Since my assumption is = apparently=20 incorrect, then over a beer, you need to explain it to me one = more=20 time how the RPM is a factor in the computation of fuel = injection=20 time.
 
I strongly suspected = that Ve=20 wasn't really a factor for the reasons you stated, too bad=20 {:>)
 
Ed = Anderson
 
I think semantics are = confusing=20 both of us (or me at least  : ).  If we look at it = in terms=20 of a single intake cycle, rpm does not figure into the = equation. If=20 you look at it in terms of CC per minute or gallons per hour, = it=20 does.   However,  in the latest version of = the=20 software (which Rusty has), rpm does have an effect in that a=20 different MAP table is used for high and low RPM ranges.  =
 
Tracy  (who would = never=20 accuse Ed of being slow !  )
 
OK, Tracy, I agree about the semantics = and the=20 two points of reference.  Within terms of  a single = intake=20 cycle rpm does not directly figure into the fuel injection = time=20 calculation.  However, it is certainly a factor in terms = of=20 CC/Minute as there are more intake cycles at 5000 rpm than = 3000=20 rpm.  So when I stated earlier that RPM was not a = computation=20 factor in determining injector pulse width time, I did = not mean=20 it was not a factor in determining how many CC/Gallons of fuel = flow=20 were consumed.  So if you consider that total injection = time (and=20 therefore total fuel flow) is a product of injection time = computed=20 (based on manifold pressure) AND number of times that = injection=20 cycle is trigger per unit time (RPM), then I think we are on = the same=20 sheet of music.  RPM IS a factor in determining fuel = flow, just=20 not in calculating injector pulse width. (I = think).
 
Thanks for the explanation (again=20 {:>)).
 
Ed Anderson
 
 
 
 
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