Return-Path: Received: from relay04.roc.ny.frontiernet.net ([66.133.131.37] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2590183 for flyrotary@lancaironline.net; Tue, 23 Sep 2003 00:06:40 -0400 Received: (qmail 8617 invoked from network); 23 Sep 2003 04:06:39 -0000 Received: from unknown (HELO frontiernet.net) ([67.50.124.115]) (envelope-sender ) by relay04.roc.ny.frontiernet.net (FrontierMTA 2.3.6) with SMTP for ; 23 Sep 2003 04:06:39 -0000 Message-ID: <3F6FB94C.EDCB4B5@frontiernet.net> Date: Mon, 22 Sep 2003 23:09:00 -0400 From: Jim Sower X-Mailer: Mozilla 4.77 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Some turbo thoughts from a pro .... References: Content-Type: multipart/alternative; boundary="------------96B7E7E2D95F1DC054E6F031" --------------96B7E7E2D95F1DC054E6F031 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit <... present a formula or graph that shows HP vs air temp ...> Air density vs air temp is no trick. HP would vary much more per application (witness Ed's dramatic increase in static RPM at low temps, which are much less dramatic with other engines). That said, charge temperature is a really REALLY important consideration, and cooler is gooder regardless of what kind of engine you have, and if it's all that important, it should really REALLY be monitored and watched. Otherwise, you don't really know what you're dealing with. When Turbo Tom is talkin', ole Jim needs to be listenin', and TT says "...charge temps are EVERYTHING ... intercooling is a MUST ...". I take him at his word. Besides, it makes PERFECT sense .... Jim S. Finn Lassen wrote: > Now these are real loose numbers from memory. But on a 90F day > I'm not seeing much more than 10GPH climbing out through > 1500'. > I seem to recall seeing 13+ GPH on a 50 or 60F day. > > But surely someone here should be able to present a formula or > graph that shows HP vs air temp. > > Finn > > Russell Duffy wrote: > >> (antagonizing text deleted ) Of course, by fuel flow, >> I'm only producing 120 (hot day) to 150 (cold day) >> HP. You're saying you have a 30 HP difference between hot >> and cold days? Holy cow !!! Do you have intake temps to go >> along with that? If not, what would be your definition of >> hot and cold? I'm going to have to find those >> intercoolers... >> >> Thanks for the info.Rusty > -- Jim Sower Crossville, TN; Chapter 5 Long-EZ N83RT, Velocity N4095T --------------96B7E7E2D95F1DC054E6F031 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit <... present a formula or graph that shows HP vs air temp ...>
Air density vs air temp is no trick.  HP would vary much more per application (witness Ed's dramatic increase in static RPM at low temps, which are much less dramatic with other engines).  That said, charge temperature is a really REALLY important consideration, and cooler is gooder regardless of what kind of engine you have, and if it's all that important, it should really REALLY be monitored and watched.  Otherwise, you don't really know what you're dealing with.  When Turbo Tom is talkin', ole Jim needs to be listenin', and TT says "...charge temps are EVERYTHING ... intercooling is a MUST ...".
I take him at his word.  Besides, it makes PERFECT sense .... Jim S.

Finn Lassen wrote:

Now these are real loose numbers from memory. But on a 90F day I'm not seeing much more than 10GPH climbing out through 1500'.
I seem to recall seeing 13+ GPH on a 50 or 60F day.

But surely someone here should be able to present a formula or graph that shows HP vs air temp.

Finn

Russell Duffy wrote:

(antagonizing text deleted <g>)  Of course, by fuel flow, I'm only producing 120 (hot day) to 150 (cold day) HP. You're saying you have a 30 HP difference between hot and cold days?  Holy cow !!!  Do you have intake temps to go along with that?  If not, what would be your definition of hot and cold?  I'm going to have to find those intercoolers...

Thanks for the info.Rusty

--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T
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