X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 84 [XXX] (57%) BODY: contains "ambien" obfuscated (29%) URL: contains host with port number (14%) BODY: contains stock spam words Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.25.9.100] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 2038258 for flyrotary@lancaironline.net; Fri, 11 May 2007 12:40:48 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-01.southeast.rr.com (8.13.6/8.13.6) with SMTP id l4BGdwl4008055 for ; Fri, 11 May 2007 12:39:59 -0400 (EDT) Message-ID: <001901c793eb$42a389c0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EC2 question Date: Fri, 11 May 2007 12:41:44 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0016_01C793C9.BB376DB0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0016_01C793C9.BB376DB0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable You had better not doubt Tracy's products as my bird (that you claim you = want a flight in) is stuffed with them {:>). My experience is once you have "tuned" your fuel map, then little = adjustment is required. But remember your are setting the fuel map for = basically 64 bins (yes, there are 64 used below 3000 rpm and 64 used = above 3000 rpm for a total of 128 - but basically you use one or the = other - mostly the >3000). So 64 bins to cover an infinite ( or at = least very large) possible pressure points - see where I am heading? So you have 64 pressure bins which you tune. Now when you tune = (program) in the value you desire for a bin, you have automatically = selected the Manifold pressure (as influenced by ambient pressure). = So lets say your are flying at 6500 msl with the OAT at 42F, then your = intake temperature and manifold pressure are going to somewhat different = than ambient conditions (inlet temp will undoubtedly be higher and = manifold pressure will certainly be no higher (unless under boost) than = ambient and probably lower. But lets say your are at 22" HG manifold = pressure and 5600 rpm and air inlet Temp is 50F. =20 In any case, you move the mixture control until the engine is purring = just right and then hit the store button. A value is stored in a = particular fuel map bin that is a reflection of all those ambient = conditions you are operating with at that particular moment. Now that = value will get adjusted for inlet air temperature, but that's about it. = Now you are back flying two days later. You're at 6500 MSL, inlet temp = is the same and you have as best you can get it 22" Hg. But, is your = mixture control set exactly where it was two days before under these = conditions - or just close? Remember the manual mixture control setting = always influences the value used to determine injector on time. Are you = really at 22" Hg or just very close. The point I am trying to make it = is difficult to exactly fly two flights where conditions are identical. = So you look over at your A/F indicator and flow rate and decide they are = a bit lower than you want and you bump the mixture control a hair. = All I am really saying is yes, if conditions are exactly the same no = adjustment is required - otherwise you may want to "adjust" it a bit to = meet current conditions {:>) I personally find I am more likely to adjust the mixture control when I = am in the landing phase, as you may be varying between the two maps at = times, manifold pressure and other parameters are changing rapidly and I = really like my engine to be purring in the pattern - no burps, = hesitations, etc.=20 Do you need to do this - if you have done a good job of tuning - = probably not. But, lets hear from others and their experience. I would = not be a candidate for a single control system - I like to fiddle and = adjust too much {:>). Regarding Fuel system injection approach. Like most things Mass flow = and air density systems have pros and cons. Most mass flow systems I = have seen either had some sort of flap in the intake that got deflected = X amount reflecting air flow or else had a heated element which = temperature reflected air flow, or vortex generation schemes which also = did the same. The speed density really only needs manifold pressure and = temperature ( to determine the air density). Since our engines are = positive displacement pumps they displace the the same (known) volume = of space in a revolution regardless of the amount of air in them. So if = you know the volume displaced, the only other thing you need to know is = the density of the air in that displacement space for to determine the = amount of fuel you need to inject. =20 So I personally believe the air density system is more bullet proof, = less complex, and lighter than a Mass Flow type. If you had a typical = mass flow system and your throttle body plenum/mount fell off what = would the system do with air no longer flowing through it. With the = speed Density system - it would go to full throttle and you would have = to use your injector or ignition switch to modulate the power. Also I = think it is much easier to have a redundant manifold pressure sensor = than a second mass flow sensor. But, that is just a personal opinion, I've never designed a Mass flow = one. Ed ----- Original Message -----=20 From: Thomas Jakits=20 To: Rotary motors in aircraft=20 Sent: Friday, May 11, 2007 10:54 AM Subject: [FlyRotary] Re: EC2 question Thanx for the answers. I never doubted Tracy's product, I just want to understand its = operation. Numbers (sold and flying) speak for itself. My question was more to the degree of automation the EC2 provides: Is it necessary to manually (constantly) re-tune mixture or is this = automatic, once the base maps are set? Single Lever - "no need to think = about" - operation? I remember the Speed-Density versus Mass-Airflow discussion from the = Mustang 5.0 mags and forums. I understand that Mass-Airflow is easier to tune/play/aftermarket = with, but that Speed-Density is more efficient/precise/expensive?? I assume that a (any) controller would be rpm-adjusted by the pilot - = hold rpm. Prop-pitch could also be pilot set (as it is in about every C/S = flying) Prehistoric (Lycontsaurus) school also has you manage mixture - I = assume EC2 will do that all by itself, no matter what the throttle = position is (within set limits - no way to maintain rpm if pitch is too = steep...) About "the" book - well, whatever.... :) About the rest: I wonder when someone is showing PL some "detonation"- = parts with Tracy's surviving seals! Probably he will look to the other = side and say "I can't see what you talk about!"=20 There is people in the world that maintain that the sky is green - = because they say so! The weird thing is, sometimes the urge to be right is so strong, they = believe it themselves. Even if you proof these people wrong they will come up with the most = fantastic excuses... Had my share of contact with alike people.... If I ever get near Ed he better gives me a ride in his bird! ...or I am going to tell it that plug's up, evap-cores and pinched = ducts are "green" !=20 TJ :) =20 On 5/11/07, Finn Lassen wrote:=20 I'm not Tracy but the way I understand it is you don't want this. Why did Powersport get such poor fuel efficiency against the = Lycoming=20 fly-offs in the RV-8's. Because there was no option for leaning past max power setting. I guess you could have a max-power/best-fuel-efficiency switch, but = then again you don't have a single lever. And there would probably be = times=20 when you want something in-between and you're back to the variable mixture control. Ed has already answered the CS BS. Finn Thomas Jakits wrote: > Tracy, > ... > Single power-lever (maybe the prop-rpm separate or even that=20 > controlled by single lever), no mixture adjustment needed... > > Best Regards, > > TJ -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0016_01C793C9.BB376DB0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
You had better not doubt Tracy's products as my = bird (that=20 you claim you want a flight in) is stuffed with them = {:>).
 
My experience is once you have "tuned" your fuel = map, then=20 little adjustment is required.  But remember your are setting the = fuel map=20 for basically 64 bins (yes, there are 64 used below 3000 rpm and 64 used = above=20 3000 rpm for a total of 128 - but basically you use one or the other - = mostly=20 the >3000).  So 64 bins to cover an infinite ( or at least very = large)=20 possible pressure points - see where I am heading?
 
So you have 64 pressure bins which you = tune.  Now=20 when you tune (program) in the value you desire for a bin, you have=20 automatically selected   the  Manifold pressure (as influenced = by=20 ambient pressure).  So lets say your are flying at 6500 msl with = the OAT at=20 42F, then your intake temperature and manifold pressure are going to = somewhat=20 different than ambient conditions (inlet temp will undoubtedly be higher = and=20 manifold pressure will certainly be no higher (unless under boost) than = ambient=20 and probably lower.  But lets say your are at 22" HG manifold = pressure and=20 5600 rpm and air inlet Temp is 50F. 
 
In any case, you move the mixture control until = the engine=20 is purring just right and then hit the store button.  A value is = stored=20 in a particular  fuel map bin that is a reflection of all = those=20 ambient conditions you are operating with at that particular = moment.  Now=20 that value will get adjusted for inlet air temperature, but that's about = it.  
 
 Now you are back flying two days = later.  You're=20 at 6500 MSL, inlet temp is the same and you have as best you can get it = 22"=20 Hg.  But, is your mixture control set exactly where it was two days = before=20 under these conditions - or just close?  Remember the manual = mixture=20 control setting always influences the value used to determine injector = on=20 time.  Are you really at 22" Hg or just very close.  The point = I am=20 trying to make it is difficult to exactly fly two flights where = conditions are=20 identical.  So you look over at your A/F indicator and flow rate = and decide=20 they are a bit lower than you want and you bump the mixture control = a=20 hair.    All I am really saying is yes, if conditions are = exactly=20 the same no adjustment is required - otherwise you may want to "adjust" = it a bit=20 to meet current conditions {:>)
 
I personally find I am more likely to adjust the = mixture=20 control when I am in the landing phase, as you may be varying between = the two=20 maps at times, manifold pressure and other parameters are changing = rapidly and I=20 really like my engine to be purring in the pattern - no burps, = hesitations,=20 etc. 
 
 Do you need to do this - if you have done = a good job=20 of tuning - probably not.  But, lets hear from others and their=20 experience.  I would not be a candidate for a single control system = - I=20 like to fiddle and adjust too much {:>).
 
Regarding Fuel system injection approach.  = Like most=20 things Mass flow and air density systems have pros and cons.  Most = mass=20 flow systems I have seen either had some sort of flap in the intake that = got=20 deflected X amount reflecting air flow or else had a heated element = which=20 temperature reflected air flow, or vortex generation schemes which also = did the=20 same.  The speed density really only needs manifold pressure and=20 temperature ( to determine the air density).  Since our = engines are=20 positive displacement pumps they displace the the same (known) =  volume of=20 space in a revolution regardless of the amount of air in them.  So = if you=20 know the volume displaced, the only other thing you need to know is the = density=20 of the air in that displacement space for to determine the amount of = fuel you=20 need to inject. 
 
So I personally believe the air density system = is more=20 bullet proof, less complex, and lighter than a Mass Flow type.  If = you had=20 a typical mass flow system and your throttle body plenum/mount =  fell off=20 what would the system do  with air no longer flowing through = it.  With=20 the speed Density system - it would go to full throttle and you = would have=20 to use your injector or ignition switch to modulate the power.  = Also I=20 think it is much easier to have a redundant manifold pressure sensor = than a=20 second mass flow sensor.
 
 But, that is just a personal opinion, I've = never=20 designed a Mass flow one.
 
 
 
Ed
 
 
 
----- Original Message -----
From:=20 Thomas Jakits
Sent: Friday, May 11, 2007 = 10:54 AM
Subject: [FlyRotary] Re: EC2=20 question

Thanx for the answers.
I never doubted Tracy's product, I just want to understand its=20 operation.
Numbers (sold and flying) speak for itself.
My question was more to the degree of automation the EC2 = provides:
Is it necessary to manually (constantly) re-tune mixture or is = this=20 automatic, once the base maps are set? Single Lever - "no need to = think about"=20 - operation?
I remember the Speed-Density versus Mass-Airflow discussion from = the=20 Mustang 5.0 mags and forums.
I understand that Mass-Airflow is easier to tune/play/aftermarket = with,=20 but that Speed-Density is more efficient/precise/expensive??
 
I assume that a (any) controller would be rpm-adjusted by the = pilot -=20 hold rpm.
Prop-pitch could also be pilot set (as it is in about every C/S=20 flying)
Prehistoric (Lycontsaurus) school also has you manage = mixture - I=20 assume EC2 will do that all by itself, no matter what the throttle = position is=20 (within set limits - no way to maintain rpm if pitch is too = steep...)
 
About "the" book - well, whatever.... :)
 
About the rest: I wonder when someone is showing PL some = "detonation"-=20 parts with Tracy's surviving seals! Probably he will look to the other = side=20 and say "I can't see what you talk about!"
There is people in the world that maintain that the sky is green = -=20 because they say so!
The weird thing is, sometimes the urge to be right is so strong, = they=20 believe it themselves.
Even if you proof these people wrong they will come up with the = most=20 fantastic excuses...
 
Had my share of contact with alike people....
 
If I ever get near Ed he better gives me a ride in his = bird!
...or I am going to tell it that plug's up, evap-cores and = pinched=20 ducts are "green" !
 
TJ :)

 
On 5/11/07, Finn=20 Lassen <finn.lassen@verizon.net>=20 wrote:=20
I'm=20 not Tracy but the way I understand it is you don't want this.
Why = did=20 Powersport get such poor fuel efficiency against the Lycoming =
fly-offs=20 in the RV-8's.
Because there was no option for leaning past max = power=20 setting.

I guess you could have a = max-power/best-fuel-efficiency=20 switch, but then
again you don't have a single lever. And there = would=20 probably be times
when you want something in-between and you're = back to=20 the variable
mixture control.

Ed has already answered the = CS=20 BS.

Finn

Thomas Jakits wrote:
> Tracy,
>=20 ...
> Single power-lever (maybe the prop-rpm separate or even = that=20
> controlled by single lever), no mixture adjustment=20 needed...
>
> Best Regards,
>
>=20 TJ


--
Homepage:  http://www.flyrotary.com/
Archi= ve=20 and UnSub:   http:= //mail.lancaironline.net:81/lists/flyrotary/List.html

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