X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 01 Aug 2007 00:02:44 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-banded.atl.sa.earthlink.net ([209.86.89.70] verified) by logan.com (CommuniGate Pro SMTP 5.1.11) with ESMTP id 2223548 for lml@lancaironline.net; Tue, 31 Jul 2007 21:08:36 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.70; envelope-from=douglasbrunner@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=GpeauMgboaEsBr7d0b2Zjg4138yoTNd9Gu/F+85t1EKqPD5DEi39GHWhJ+2JDHYj; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MIMEOLE:X-ELNK-Trace:X-Originating-IP; Received: from [74.93.196.177] (helo=DFWK3391) by elasmtp-banded.atl.sa.earthlink.net with asmtp (Exim 4.34) id 1IG2gw-0004ht-Ja for lml@lancaironline.net; Tue, 31 Jul 2007 21:07:58 -0400 X-Original-Message-ID: <002a01c7d3d8$612bb700$1bd0a60a@DFWK3391> From: "Douglas Brunner" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: Template of Leading Edges X-Original-Date: Tue, 31 Jul 2007 21:07:49 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0027_01C7D3B6.D9D741A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-ELNK-Trace: ad85a799c4f5de37c2eb1477c196d22294f5150ab1c16ac0c864d17e3813b99af1421af0701c2d907316496e043915c2350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 74.93.196.177 This is a multi-part message in MIME format. ------=_NextPart_000_0027_01C7D3B6.D9D741A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Alan, I have the disadvantage of not being an engineer but it is my = understanding that drag and therefore power requirements go up rather = steeply (based on the cube) at the top end of the speed curve. Let us assume that 922F goes 15 knots faster than another similar Legacy = and that we can explain this difference based either on aerodynamics or on horsepower. (Most = likely the difference is a combination of the two) The difference in = speed between 250 and 265 is approximately 6%. If we chose to explain this difference in speed solely on a difference = in horsepower how much horsepower do we need? (Here is where it would = be very helpful if I was an engineer) By my (suspect) calculations we = would need 19% greater horsepower. So if the 250 kt plane is making 325 = hp the 265 kt plane would need to make 387 hp. If the 250 kt plane = makes 310 hp, the 265 kt plane would need to make 369 hp. =20 In my discussion with Mr. Frazier he said that he had run his engine at = about 2600 RPM and approx 26 inches manifold pressure. I doubt that his = engine makes 19% more horsepower at that setting than a stock = Continental. Some of the discussions on horsepower become more like discussions of = religion than of science. And I must admit that I am probably of the = "Oklahoma Branch" of the faith rather than the "Southern California = Branch". I simply do not believe that an approximately 15 kt difference = in speed can be explained based primarily on horsepower. On a more practical level, my engine is already built (IO-550, 10:1 = compression, dual mags, built by Monty Barrett) so I cannot change that. = My only chance to get 265 kts is to attend to the aerodynamics. I may = have a chance to actually test and see how much increase (or decrease) = in speed I can get by paying attention to the leading edges. Most = likely my plane will be flying before I get a chance to "template" the = leading edges. I will then have an opportunity to see if there is a = "before vs. after" difference. D. Brunner ----- Original Message -----=20 From: Alan Adamson=20 To: lml@lancaironline.net=20 Sent: Tuesday, July 31, 2007 6:12 PM Subject: [LML] Re: Template of Leading Edges It was 922F. Given this discussion, I'd suggest a slightly different approach. Most of the Legacys run in the 240-250kt range (those quicker ones = anyway). If indeed this one is in the mid 260's, I doubt subtle changes to the = bodywork to better match wing airfoils is the magic as that is a 15kts = differential from the 250 mark (which very few stock legacys make) This particular airplane makes that mid 260 number on 19.5 gph (the = owner had a card in the airplane with the specifics). It gave no MP/RPM = numbers however. Also, it has a highly modified LyCon IO-550 engine with 10:1 = compression and a supposedly dyno'd 375HP. I heard a rumor that it = actually made 390 on the dyno and had to be "turned down" (dunno how you = do that with a normally aspirated engine) to make the 375HP. As everyone knows, the only semi accurate way to determine accuracy in = TAS numbers is to use a spreadsheet by the National Test Pilot = association, here's the link http://www.ntps.edu/Files/GPS%20PEC.XLS Use the tab that requires 4 legs. It's pretty simple to do this, just = pick an altitude where you can make 75% power, setup for your runs and = level out and let your speed build. Now turn on your Autopilot and = slave it to the GPS. You want to fly 90 degree legs (90, 180, 270, 360) = all 4 of them. For each leg, write down the following information Alt, RPM, MP, OAT, PALT, DALT, IAS, TAS (if you have onboard = indication), GPS TRACK, and GPS GROUND SPEED Now when you have landed, plug in the GPS TRACK and the GPS GROUND = SPEED into that 4 leg tab on the spread sheet and see what the TAS was. = If it is higher or lower than your indicated TAS, then you have an error = in your IAS (which is what feeds the TAS CALC in most GLASS panels), or = your OAT. I did notice that this particular airplane had GRT Glass panels in it = and that it used a slightly different ram air setup. As a note, Scott Alair ran the AVC at 297mph or 253kts in a stock = engined legacy, but I believe he was turning 2900 RPM and I don't know = what his MP was. Last year at reno, a legacy right out of build assist = with no paint or body work turned 290mph laps at reno but this one also = had a modified motor from performance engines altho it turned stock RPM = (2800). The reason I make these last 2 points. HP is king when trying to put = up speed numbers. So if the mid 260's is everything full forward, what = is the typical cruise in this airplane with a more standard fuel burn? = That will tell probably more as it relates to speed than a speed run = will. My .02, Alan -------------------------------------------------------------------------= ----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = VTAILJEFF@aol.com Sent: Tuesday, July 31, 2007 8:17 AM To: lml@lancaironline.net Subject: [LML] Re: Template of Leading Edges What is Mr. Frazier's N Number? Jeff -------------------------------------------------------------------------= ----- Get a sneak peek of the all-new AOL.com. ------=_NextPart_000_0027_01C7D3B6.D9D741A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Alan,
 
I have the disadvantage of not being an engineer but it is my = understanding=20 that drag and therefore power requirements go up rather steeply = (based on=20 the cube) at the top end of the speed curve.
 
Let us assume that 922F goes 15 knots faster than another similar = Legacy=20 and that we can explain
this difference based either on aerodynamics or on = horsepower.  (Most=20 likely the difference is a combination of the two)  The difference = in speed=20 between 250 and 265 is approximately 6%.
 
If we chose to explain this difference in speed solely on = a=20 difference in horsepower how much horsepower do we need?  (Here is = where it=20 would be very helpful if I was an engineer) By my (suspect) calculations = we=20 would need 19% greater horsepower.  So if the 250 kt plane is = making 325 hp=20 the 265 kt plane would need to make 387 hp.  If the 250 kt plane = makes 310=20 hp, the 265 kt plane would need to make 369 hp. 
 
In my discussion with Mr. Frazier he said that he had run his = engine at=20 about 2600 RPM and approx 26 inches manifold pressure.  I doubt = that his=20 engine makes 19% more horsepower at that setting than a stock = Continental.
 
Some of the discussions on horsepower become more like discussions = of=20 religion than of science.  And I must admit that I am probably of = the=20 "Oklahoma Branch" of the faith rather than the "Southern California=20 Branch".  I simply do not believe that an approximately 15 kt = difference in=20 speed can be explained based primarily on horsepower.
 
On a more practical level, my engine is already built (IO-550, 10:1 = compression, dual mags, built by Monty Barrett) so I cannot change = that. =20 My only chance to get 265 kts is to attend to the = aerodynamics. I may=20 have a chance to actually test and see how much increase (or decrease) = in speed=20 I can get by paying attention to the leading edges.  Most likely my = plane=20 will be flying before I get a chance to "template" the leading = edges.  I=20 will then have an opportunity to see if there is a "before vs. after"=20 difference.
 
D. Brunner
----- Original Message -----
From:=20 Alan=20 Adamson
Sent: Tuesday, July 31, 2007 = 6:12=20 PM
Subject: [LML] Re: Template of = Leading=20 Edges

It was=20 922F.
 
Given = this discussion,=20 I'd suggest a slightly different approach.
 
Most of = the Legacys run=20 in the 240-250kt range (those quicker ones anyway).
 
If indeed = this one is=20 in the mid 260's, I doubt subtle changes to the bodywork to better = match wing=20 airfoils is the magic as that is a 15kts differential from the 250 = mark (which=20 very few stock legacys make)
 
This = particular=20 airplane makes that mid 260 number on 19.5 gph (the owner had a card = in the=20 airplane with the specifics).  It gave no MP/RPM numbers=20 however.
 
Also, it = has a highly=20 modified LyCon IO-550 engine with 10:1 compression and a supposedly = dyno'd=20 375HP.  I heard a rumor that it actually made 390 on the dyno and = had to=20 be "turned down" (dunno how you do that with a normally aspirated = engine) to=20 make the 375HP.
 
As = everyone knows, the=20 only semi accurate way to determine accuracy in TAS numbers is to use = a=20 spreadsheet by the National Test Pilot association, here's the link http://www.ntps.edu/File= s/GPS%20PEC.XLS
 
Use the = tab that=20 requires 4 legs.  It's pretty simple to do this, just pick an = altitude=20 where you can make 75% power, setup for your runs and level out and = let your=20 speed build.  Now turn on your Autopilot and slave it to the = GPS. =20 You want to fly 90 degree legs (90, 180, 270, 360) all 4 of = them.
 
For each = leg, write=20 down the following information
Alt, RPM, = MP, OAT,=20 PALT, DALT, IAS, TAS (if you have onboard indication), GPS TRACK, and = GPS=20 GROUND SPEED
 
Now when = you have=20 landed, plug in the GPS TRACK and the GPS GROUND SPEED into that 4 leg = tab on=20 the spread sheet and see what the TAS was.  If it is higher or = lower than=20 your indicated TAS, then you have an error in your IAS (which is what = feeds=20 the TAS CALC in most GLASS panels), or your OAT.
 
I did = notice that this=20 particular airplane had GRT Glass panels in it and that it used a = slightly=20 different ram air setup.
 
As a = note, Scott Alair=20 ran the AVC at 297mph or 253kts in a stock engined legacy, but I = believe he=20 was turning 2900 RPM and I don't know what his MP was.  Last year = at=20 reno, a legacy right out of build assist with no paint or body work = turned=20 290mph laps at reno but this one also had a modified motor from = performance=20 engines altho it turned stock RPM (2800).
 
The = reason I make these=20 last 2 points.  HP is king when trying to put up speed = numbers.  So=20 if the mid 260's is everything full forward, what is the typical = cruise in=20 this airplane with a more standard fuel burn?  That will tell = probably=20 more as it relates to speed than a speed run will.
 
My = .02,
Alan

From: Lancair Mailing List=20 [mailto:lml@lancaironline.net] On Behalf Of=20 VTAILJEFF@aol.com
Sent: Tuesday, July 31, 2007 8:17=20 AM
To: lml@lancaironline.net
Subject: [LML] Re: = Template=20 of Leading Edges

What is Mr. Frazier's N Number?
 
Jeff



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