X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-m06.mx.aol.com ([64.12.138.200] verified) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTP id 2604016 for flyrotary@lancaironline.net; Tue, 18 Dec 2007 15:17:51 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.138.200; envelope-from=WRJJRS@aol.com Received: from imo-d04.mx.aol.com (imo-d04.mail.aol.com [172.18.150.228]) by imr-m06.mx.aol.com (v107.10) with ESMTP id RELAYIN6-747682ac31d6; Tue, 18 Dec 2007 15:17:07 -0400 Received: from WRJJRS@aol.com by imo-d04.mx.aol.com (mail_out_v38_r9.3.) id q.d4d.168a315d (37142) for ; Tue, 18 Dec 2007 14:46:38 -0500 (EST) Received: from WEBMAIL-DG02 (webmail-dg02.sim.aol.com [205.188.171.66]) by cia-ma03.mx.aol.com (v121.4) with ESMTP id MAILCIAMA034-911647682397138; Tue, 18 Dec 2007 14:46:31 -0500 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: Supercharging Date: Tue, 18 Dec 2007 14:46:00 -0500 X-AOL-IP: 172.18.150.228 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: wrjjrs@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CA0FC5C008C470_E14_7F60_WEBMAIL-DG02" X-Mailer: AOL Webmail 33161-STANDARD Received: from 65.161.241.3 by WEBMAIL-DG02 (205.188.171.66) with HTTP (WebMailUI); Tue, 18 Dec 2007 14:46:00 -0500 Message-Id: <8CA0FC5C008C470-E14-3EBB@WEBMAIL-DG02> X-Spam-Flag: NO ----------MB_8CA0FC5C008C470_E14_7F60_WEBMAIL-DG02 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii" One thing Guys, A turbocharger properly applied can actually increase the engine efficiency by recouping the "wasted" exhaust energy. It takes careful design, but there it is. I have never seen that with a supercharger. Bill Jepson -----Original Message----- From: Greg Ward To: Rotary motors in aircraft Sent: Tue, 18 Dec 2007 9:18 am Subject: [FlyRotary] Re: Supercharging Thanks Ed;? The below is one of the reasons for looking at a SC in the first place. Specifically on a missed approach and go-around, in a ticklish spot, the responsiveness of the SC vs. the time it takes a TC to spool up, might be an advantage. And, as I have been hearing, back pressure (from a turbo) kills HP in a rotary. Maybe I'm picking the nit a little hard here??? Greg? ? There are certainly advantages to a supercharger in some applications - and? > to a turbo in others. The immediate boost response of a roots type blower > is about the only reason they are the bedrock of the top end drag racers. > Unlike a turbo which needs some time to spool up, the roots type > superchargers produce boost much quicker. There are several types on > impellers designed to increase the efficiency of the root types blowers, > but I am not aware of any that approach the centrifugal impeller in > efficiency.? >? >? > While the turbo uses the "free" exhaust flow energy, you do get back > pressure with the turbocharger that effects (decreases) engine power so > that has to be considered also. But, overall, its my understanding that > the turbo is a bit more efficient and also does not decrease crankshaft > power (at least not as much) as a supercharger. However, there may be > other reasons (like not having to have all that heated exhaust pipes > routing around to and from a turbocharger) as well as cost for using one > vs the other.? >? > Gee, its great to be back {:>)? >? > my 0.02? >? > Ed? >? > --? > Homepage: http://www.flyrotary.com/? > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html? > ? --? Homepage: http://www.flyrotary.com/? Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html? ________________________________________________________________________ More new features than ever. Check out the new AOL Mail ! - http://webmail.aol.com ----------MB_8CA0FC5C008C470_E14_7F60_WEBMAIL-DG02 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset="us-ascii" One thing Guys,
A turbocharger properly applied can actually increase the engine efficiency by recouping the "wasted" exhaust energy. It takes careful design, but there it is. I have never seen that with a supercharger.
Bill Jepson

-----Original Message-----
From: Greg Ward <gregw@onestopdesign.biz>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Tue, 18 Dec 2007 9:18 am
Subject: [FlyRotary] Re: Supercharging

Thanks Ed;
The below is one of the reasons for looking at a SC in the first place. Specifically on a missed approach and go-around, in a ticklish spot, the responsiveness of the SC vs. the time it takes a TC to spool up, might be an advantage. And, as I have been hearing, back pressure (from a turbo) kills HP in a rotary. Maybe I'm picking the nit a little hard here??
Greg

<snip> There are certainly advantages to a supercharger in some applications - and
> to a turbo in others. The immediate boost response of a roots type blower > is about the only reason they are the bedrock of the top end drag racers. > Unlike a turbo which needs some time to spool up, the roots type > superchargers produce boost much quicker. There are several types on > impellers designed to increase the efficiency of the root types blowers, > but I am not aware of any that approach the centrifugal impeller in > efficiency.
>
>
> While the turbo uses the "free" exhaust flow energy, you do get back > pressure with the turbocharger that effects (decreases) engine power so > that has to be considered also. But, overall, its my understanding that > the turbo is a bit more efficient and also does not decrease crankshaft > power (at least not as much) as a supercharger. However, there may be > other reasons (like not having to have all that heated exhaust pipes > routing around to and from a turbocharger) as well as cost for using one > vs the other.
>
> Gee, its great to be back {:>)
>
> my 0.02
>
> Ed
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html

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