Return-Path: Received: from [199.185.220.223] (HELO priv-edtnes16-hme0.telusplanet.net) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2581110 for flyrotary@lancaironline.net; Tue, 16 Sep 2003 02:49:05 -0400 Received: from Endurance ([209.52.209.152]) by priv-edtnes16-hme0.telusplanet.net (InterMail vM.5.01.05.17 201-253-122-126-117-20021021) with SMTP id <20030916064901.BRQX1925.priv-edtnes16-hme0.telusplanet.net@Endurance> for ; Tue, 16 Sep 2003 00:49:01 -0600 From: "Haywire" To: "Rotary motors in aircraft" Subject: RE: [FlyRotary] turbo performance? Date: Mon, 15 Sep 2003 23:48:54 -0700 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0046_01C37BE3.EC37D320" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 This is a multi-part message in MIME format. ------=_NextPart_000_0046_01C37BE3.EC37D320 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit MessageHi Rusty; You're probably not as curious now about this since you've been out wrangling up some extra ponies, but here it is anyways... Just how much below your expectations was you climb performance? Lots. I had dreams of 2000fpm, but was expecting 1200fpm without using boost, but managed a dismal 500fpm. However aircraft weight was approx 1700 lbs, as there was two of us on board and I was carrying more fuel than necessary. How much boost were you running? Full throttle, or part throttle to lower boost? We were running 0psi boost, which is less than 3/4 throttle. At one point it creeped up to 2 psi but I throttled back. I had been running under the idea that 0 boost would equal an NA, even though in the back of my mind I remembered someone speculating that it would require at least 2 psi to overcome the backpressure caused by the turbo. Leon has confirmed this for me. 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 spoke with Dave Atkins as I knew he was also using an IVO Magnum. His is also a 76" 3-blade, so maybe I'm as overpropped as I had thought. He has reprofiled his blades, but he says that only helped at the top end. Apparently some NASA engineer helped him with it and it allowed him to get the top end numbers that are otherwise elusive for IVO props. I can't tell you what pitch I'm running as mine is cockpit adjustable, so I've cycled through a few times. A big priority will be to calibrate the electronic constant speed governor so then I should be able to dial it in for the climb RPM. This has to be done under flight conditions. 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. The plan for flight #5 was to "press the go button":-), and use all available boost on take-off, just to see what she really had in her, unfortunately the EWP seizing moments before we taxied onto the active runway put a halt on that idea. The weather here has really cooled off in the last week, this evening as I was riding my motorbike home, it was downright freezing, so by the time I get going again I'll do some air density calcs before I pour all the coals on the fire. I'm also considering removing my wings and bringing my plane home, but for different reasons. In less than a week I have to go to the bush to work as a hunting guide for a few weeks, then when I return I have less than three weeks before I return to tech school. Since we have an incoming exam that is worth 25% of final mark, I'd best get my nose in the books. I don't return from school till Christmas, so realistically I'm looking at January before I can resume flight testing. As a rookie pilot, flight testing in the winter might not be the best idea, so it may even be spring before I can get really serious about again. Right now I pay a pretty reasonable rate for hangar space, but it goes up substantially in the winter, so bringing it home may be the best option. I can't say that I'm very happy about this, in fact I'm downright pissed off :-(, but as everyday goes by with an empty mailbox and no EWP, I'm running out of options. This is not to say that I regret trying the EWP. It was really promising right up until it quit working :-). As even the best products can fail, I'm willing to give it the benefit and try a replacement. Leon has helped by sending a replacement right away, but somewhere it got lost, so he has sent yet another, but I'm beginning to lose faith in our mail system. I'm really hoping I can get another chance to try this pump before I'm forced to bring it home, as if it is not successful it would be allot easier to convert to a mechanical pump here in my own shop. S. Todd Bartrim Turbo 13B RV-9Endurance C-FSTB http://www3.telus.net/haywire/RV-9/C-FSTB.htm "Whatever you vividly imagine, Ardently desire, Sincerely believe in, Enthusiastically act upon, Must inevitably come to pass". ------=_NextPart_000_0046_01C37BE3.EC37D320 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message
Hi=20 Rusty;
    You're probably not as curious now about this since you've been = out=20 wrangling up some extra ponies, but here it is = anyways...
 
Just=20 how much below your expectations was you climb=20 performance? 
Lots. = I had dreams=20 of 2000fpm, but was expecting 1200fpm without using boost, but managed a = dismal=20 500fpm. However aircraft weight was approx 1700 lbs, as there was two of = us on=20 board and I was carrying more fuel than necessary.
How much boost were you = running? =20 Full throttle, or part throttle to lower = boost?
We were=20 running 0psi boost, which is less than 3/4 throttle. At one = point it=20 creeped up to 2 psi but I throttled back. I had been running under the = idea that=20 0 boost would equal an NA, even though in the back of my mind I = remembered=20 someone speculating that it would require at least 2 psi to overcome the = backpressure caused by the turbo. Leon has confirmed this for=20 me.
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 spoke with=20 Dave Atkins as I knew he was also using an IVO Magnum. His is also a 76" = 3-blade, so maybe I'm as overpropped as I had thought. He has reprofiled = his=20 blades, but he says that only helped at the top end. Apparently some = NASA=20 engineer helped him with it and it allowed him to get the top end = numbers that=20 are otherwise elusive for IVO props. I can't tell you what pitch I'm = running as=20 mine is cockpit adjustable, so I've cycled through a few times. A big = priority=20 will be to calibrate the electronic constant speed governor so then I = should be=20 able to dial it in for the climb RPM. This has to be done under flight=20 conditions.
 
 I know you've run as = much as 6 psi=20 on the ground, so I'm guessing that you were probably running more = than I was=20 for these flights, so you may not be as far behind the curve as I = am.  
The plan for=20 flight #5 was to "press the go button":-), and use all available boost = on=20 take-off, just to see what she really had in her, unfortunately the EWP = seizing=20 moments before we taxied onto the active runway put a halt on that idea. =
The weather=20 here has really cooled off in the last week, this evening as I was = riding my=20 motorbike home, it was downright freezing, so by the time I get going = again I'll=20 do some air density calcs before I pour all the coals on the=20 fire.
 
I'm also=20 considering removing my wings and bringing my plane home, but for = different=20 reasons. In less than a week I have to go to the bush to work as a = hunting guide=20 for a few weeks, then when I return I have less than three weeks before = I return=20 to tech school. Since we have an incoming exam that is worth 25% of = final mark,=20 I'd best get my nose in the books. I don't return from school till = Christmas, so=20 realistically I'm looking at January before I can resume flight testing. = As a=20 rookie pilot, flight testing in the winter might not be the best idea, = so it may=20 even be spring before I can get really serious about again. Right now I = pay a=20 pretty reasonable rate for hangar space, but it goes up substantially in = the=20 winter, so bringing it home may be the best option. I can't say that I'm = very=20 happy about this, in fact I'm downright pissed off :-(, but as everyday = goes by=20 with an empty mailbox and no EWP, I'm running out of=20 options.
 
This is not=20 to say that I regret trying the EWP. It was really promising right up = until it=20 quit working :-). As even the best products can fail, I'm willing to = give it the=20 benefit and try a replacement. Leon has helped by sending a replacement = right=20 away, but somewhere it got lost, so he has sent yet another, but I'm = beginning=20 to lose faith in our mail system. I'm really hoping I can get another = chance to=20 try this pump before I'm forced to bring it home, as if it is not = successful it=20 would be allot easier to convert to a mechanical pump here in my own=20 shop.

S. Todd Bartrim
Turbo 13B = RV-9Endurance
C-FSTB
http://www3.telus.net/haywire/RV-9/C-FSTB.htm

=   =20 "Whatever you vividly imagine, Ardently desire, Sincerely believe in,=20 Enthusiastically act upon, Must inevitably come to pass".

 
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