Return-Path: Received: from relay04.roc.ny.frontiernet.net ([66.133.131.37] verified) by logan.com (CommuniGate Pro SMTP 4.1.4) with ESMTP id 2601064 for flyrotary@lancaironline.net; Tue, 23 Sep 2003 23:32:53 -0400 Received: (qmail 4863 invoked from network); 24 Sep 2003 03:32:50 -0000 Received: from unknown (HELO frontiernet.net) ([170.215.98.47]) (envelope-sender ) by relay04.roc.ny.frontiernet.net (FrontierMTA 2.3.6) with SMTP for ; 24 Sep 2003 03:32:50 -0000 Message-ID: <3F7102D6.80FB3F97@frontiernet.net> Date: Tue, 23 Sep 2003 22:35:02 -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] today's turbo musings References: Content-Type: multipart/alternative; boundary="------------E0344F5921F94724D8851D86" --------------E0344F5921F94724D8851D86 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Rusty, I'm really REALLY glad you're "back". TT says "... Charge temp is EVERYTHING ..." So what if you can't get EVERYTHING - the whole 70F delta-T. Just take EVERYTHING you can get. Keep checking charge temps and trying to cram more I-C volume on your system and varying boost and comparing performance improvement. At altitude where ambient is cooler, delta-T will likely be higher. That's a GOOD thing. That's where we need the performance anyway. You get to be the lucky guy who finds out how much boost it costs us to run the turbo, heat the charge and break even on power, the guy who quantifies the dead overhead of turbocharging a 13B. You're the point man, and you're going to make a lot of progress. When there's a couple more players in the game, there will be more (and probably quicker) progress. And the "team" will gradually sneak up on that magical 70F. Hang in there. I know you'll be glad you did (and so will we :o) ... Jim s. Russell Duffy wrote: > Howdy all,Well, I took a couple intercoolers to the hanger, > and tried them on for size. The FC model would probably go in > the right cheek, without too much effort, though I'm worried > that I'll pressurize the back of my radiator and oil cooler if > I let too much air flow through it. What to do, what to > do...I also did some more research on charge temps, and > intercooler effectiveness. It seems that 70F is about the > best temp drop that you can hope for with a good intercooler, > at high boost. Unfortunately, size counts, and neither the FC > nor FD intercooler is what would be considered "good". > Adequate might even be a stretch, especially for the FD > model. In the scheme of things, <=70F really isn't a deal > breaker, and I'm starting to believe it falls in the category > of refinement, more than necessity, when talking about 10 psi > or less of boost, particularly when the higher boost is only > used at frigid altitudes. Turbo Tom considers it a necessity, > but I have to wonder what his criteria is. If I had a car, > and were limited to X psi of boost, I would consider > intercooling necessary to make the most power possible. Since > I should easily have more power than I could ever need, I > don't see the intercooler being quite as essential. What does > this all mean. Well, I'm going to fly it like it is, and use > up to 5 psi for takeoff. At altitude, I'll go for the gusto, > but will try to limit myself to 50" MAP, or 12 psi of boost > over ambient, whichever comes first. This should make a world > of difference, and I can move on to something > else. Cheers,Rusty --------------E0344F5921F94724D8851D86 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Rusty,
I'm really REALLY glad you're "back". TT says "... Charge temp is EVERYTHING ..." So what if you can't get EVERYTHING - the whole 70F delta-T. Just take EVERYTHING you can get. Keep checking charge temps and trying to cram more I-C volume on your system and varying boost and comparing performance improvement. At altitude where ambient is cooler, delta-T will likely be higher. That's a GOOD thing. That's where we need the performance anyway. You get to be the lucky guy who finds out how much boost it costs us to run the turbo, heat the charge and break even on power, the guy who quantifies the dead overhead of turbocharging a 13B.
You're the point man, and you're going to make a lot of progress. When there's a couple more players in the game, there will be more (and probably quicker) progress. And the "team" will gradually sneak up on that magical 70F.

Hang in there. I know you'll be glad you did (and so will we :o) .... Jim s.

Russell Duffy wrote:

Howdy all,Well, I took a couple intercoolers to the hanger, and tried them on for size. The FC model would probably go in the right cheek, without too much effort, though I'm worried that I'll pressurize the back of my radiator and oil cooler if I let too much air flow through it. What to do, what to do...I also did some more research on charge temps, and intercooler effectiveness. It seems that 70F is about the best temp drop that you can hope for with a good intercooler, at high boost. Unfortunately, size counts, and neither the FC nor FD intercooler is what would be considered "good". Adequate might even be a stretch, especially for the FD model. In the scheme of things, <=70F really isn't a deal breaker, and I'm starting to believe it falls in the category of refinement, more than necessity, when talking about 10 psi or less of boost, particularly when the higher boost is only used at frigid altitudes. Turbo Tom considers it a necessity, but I have to wonder what his criteria is. If I had a car, and were limited to X psi of boost, I would consider intercooling necessary to make the most power possible. Since I should easily have more power than I could ever need, I don't see the intercooler being quite as essential. What does this all mean. Well, I'm going to fly it like it is, and use up to 5 psi for takeoff. At altitude, I'll go for the gusto, but will try to limit myself to 50" MAP, or 12 psi of boost over ambient, whichever comes first. This should make a world of difference, and I can move on to something else. Cheers,Rusty

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