Return-Path: <13brv3@bellsouth.net> Received: from imf20aec.mail.bellsouth.net ([205.152.59.68] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2580403 for flyrotary@lancaironline.net; Mon, 15 Sep 2003 15:52:38 -0400 Received: from rad ([68.212.12.251]) by imf20aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030915195237.LJOF1780.imf20aec.mail.bellsouth.net@rad> for ; Mon, 15 Sep 2003 15:52:37 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "Flyrotary List" Subject: turbo performance? Date: Mon, 15 Sep 2003 14:52:38 -0500 Message-ID: <00e401c37bc2$eaccfb80$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00E5_01C37B99.01F6F380" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_00E5_01C37B99.01F6F380 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable I'm experiencing similar disappointment as Rusty in my climb speeds. However on the second flight we used the GPS to do a few runs to check = the airspeed we found that it reads 15-20 mph slow. This meant we were = climbing at too high of an airspeed. Even when we adjusted for this is was still disappointing. I feel that a big part over the problem may be that I'm over-propped. I'm currently using a 76" 3-blade IVO prop, which may = need to be shortened. I've got allot of testing to do before I shorten it = however. I have heard all the good and bad reports on the IVO prop, so I was = already aware that it may not be ideal or may be perfect, but decided that I'd = like to find out for myself.=20 =20 Todd, I got this from your initial flight post, and have been thinking about it some more. Just how much below your expectations was you climb performance? How much boost were you running? Full throttle, or part throttle to lower boost? You're initial speculation of being over = propped might put you in the same boat I'm in, that is, having less power than = you should. I know you've run as much as 6 psi on the ground, so I'm = guessing that you were probably running more than I was for these flights, so you = may not be as far behind the curve as I am. =20 =20 All along we've guessed that we would have to run maybe 1 psi to have = the same power as a NA setup, but I'm starting to wonder if that figure = isn't more like 5 psi. I'm still waiting for that call from Warp Drive to = confirm the low power that I had. One of the figures that I gave them was for = 6300 rpm, at 3 psi of boost (36 inches since I'm at sea level). I have a = feeling they're going to tell me that I was making something like 130 HP. If = so, the turbo's history. =20 =20 I'm starting to think Marko's right about the exhaust restriction = effect. =20 Cheers, Rusty =20 =20 =20 ------=_NextPart_000_00E5_01C37B99.01F6F380 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message
  I'm experiencing similar = disappointment as=20 Rusty in my climb speeds. However on the second flight we used the GPS = to do a=20 few runs to check the airspeed we found that it reads 15-20 mph slow. = This meant=20 we were climbing at too high of an airspeed. Even when we adjusted for = this is=20 was still disappointing. I feel that a big part over the problem may be = that I'm=20 over-propped. I'm currently using a  76" 3-blade IVO prop, = which may=20 need to be shortened. I've got allot of testing to do before I shorten = it=20 however. I have heard all the good and bad reports on the IVO prop, so I = was=20 already aware that it may not be ideal or may be perfect, but decided = that I'd=20 like to find out for myself.
 
Todd,  I=20 got this from your initial flight post, and have been thinking about it = some=20 more.  Just how much below your expectations was you = climb=20 performance?  How much boost were you running?  Full = throttle, or=20 part throttle to lower boost?  You're initial speculation of being = over=20 propped might put you in the same boat I'm in, that is, having less = power=20 than you should.  I know you've run as much as 6 psi on the = ground, so=20 I'm guessing that you were probably running more than I was = for these=20 flights, so you may not be as far behind the curve as I=20 am.  
 
All along=20 we've guessed that we would have to run maybe 1 psi to have = the same=20 power as a NA setup, but I'm starting to wonder if that figure isn't = more like 5=20 psi.  I'm still waiting for that call from Warp Drive to = confirm=20 the low power that I had.  One of the figures that I gave them was = for 6300=20 rpm, at 3 psi of boost (36 inches since I'm at sea level).  I have = a=20 feeling they're going to tell me that I was making something like = 130=20 HP.  If so, the turbo's history.  
 
I'm starting=20 to think Marko's right about the exhaust restriction = effect.
 
Cheers,
Rusty
 =20
 
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