X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 28 Dec 2005 22:50:25 -0500 Message-ID: X-Original-Return-Path: Received: from sfa.gami.com ([68.89.254.162] verified) by logan.com (CommuniGate Pro SMTP 5.0.5) with ESMTP id 903795 for lml@lancaironline.net; Wed, 28 Dec 2005 08:28:52 -0500 Received-SPF: none receiver=logan.com; client-ip=68.89.254.162; envelope-from=gwbraly@gami.com Received: from localhost (localhost.localdomain [127.0.0.1]) by sfa.gami.com (Postfix) with ESMTP id EC60F29C070 for ; Wed, 28 Dec 2005 07:27:34 -0600 (CST) Received: from sdf1.mail.taturbo.com (unknown [10.10.10.173]) by sfa.gami.com (Postfix) with ESMTP id 9FE1029C06E for ; Wed, 28 Dec 2005 07:27:33 -0600 (CST) X-MimeOLE: Produced By Microsoft Exchange V6.0.6603.0 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C60BB3.1B378434" Subject: RE: [LML] Re: Where has all the power gone? X-Original-Date: Wed, 28 Dec 2005 07:32:11 -0600 X-Original-Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [LML] Re: Where has all the power gone? Thread-Index: AcYKpUXp30XqphsCRSmjLEYsknCpPABDFyMA From: "George Braly" X-Original-To: "Lancair Mailing List" X-Virus-Scanned: by amavisd-new-2.3.2 (20050629) (Debian) at gami.com This is a multi-part message in MIME format. ------_=_NextPart_001_01C60BB3.1B378434 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 Brent, I agree with most of your usual excellent message. =20 >>Regarding variable timing on turbocharged engines, IMHO it is a wasted effort. Most ignition systems have some facility to retard the timing during starting. Once a turbocharged engine is started it will spend most of its power producing life in a very narrow range of operating parameters (2,400 - 2,700 RPM and 65-100% power) compared to an automotive engine (1,500 - 6,000 RPM and 10-100% power) . As Taylor observed, there is a minimum effect of timing changes at high power settings. The complexity of adding variable timing is not justified by the minimal performance gains.<< =20 At one time, I totally agreed with the thought you expressed, above. =20 However, subsequent consideration, investigation, and testing has revealed some surprising benefits for turbocharged engines from *properly executed* variable timing. =20 =20 Next time you are down south of Mason-Dixon, please find an excuse to drop in and see us. We can discuss it and if we have an engine up and running on the test stand, I think I can show you why it has more merit than it might at first appear based on the analysis you have stated. =20 Regards, George =20 =20 =20 =20 =20 =20 =20 ------_=_NextPart_001_01C60BB3.1B378434 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

Brent,   I agree with most of your = usual excellent message.

 

>>Regarding variable timing on = turbocharged engines, IMHO it is a wasted effort. Most ignition systems have some = facility to retard the timing during starting. Once a turbocharged engine is = started it will spend most of its power producing life in a very narrow range of = operating parameters (2,400 - 2,700 RPM and 65-100% power) compared to an = automotive engine (1,500 - 6,000 RPM and 10-100% power) . As Taylor observed, there is a minimum = effect of timing changes at high power settings. The complexity of adding variable = timing is not justified by the minimal performance = gains.<<

 

At one time,  I totally agreed with the = thought  you expressed, above.  

 

However,  subsequent consideration, = investigation,  and testing has revealed  some surprising benefits for turbocharged = engines from *properly = executed*  variable timing.  

 

Next time you are down south of = Mason-Dixon,  please find an excuse to drop in and see us.   We can discuss it and = if we have an engine up and running on the test stand,  I think I can show you = why it has more merit than it might at first appear based on the analysis you have = stated.

 

Regards,  = George

 

 

   =    

 

 

 

 

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