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Chris/Group;
Thanks for the kind words regarding my turbo setup.
My system has no waste gate. I contacted Greg Richter the Blue Mountain EFIS guy when he had a Turbo 13b in his canard. I have the same turbo he used, and asked him similar questions. IIRC my turbo is a Turbonetics 60-1 whith P trim and .67 AR. That's supposed to be a fairly 'loose' turbo that will build boost late at higher power and RPM.
He said leave out the waste gate and blow off valve. Fly the aircraft first, and find out if you need them or not. He didn't need one. So I followed Kelly Johnson's advice: Add lightness and simplicate. I noticed in Tracy's first flight report that his weight control program paid off in flight characteristics. I'm trying hard to do the same.
If I have an overboost condition, a looser turbine housing will be tried. I should take pressure readings before and after the throttle body. Simply put, the Turbo output is controlled by heat input. If the turbo is putting out too much, then close the throttle some.
My ground running so far has only been up to 3600 engine RPM, and that is a modest throttle position / manifold pressure. I'll find out more when I run at higher power settings. When I finish the engine upgrades (secondary injector relocation, turbo oil supply and drain upgrades, oil cooler and radiator relocations and new fiberglass ducts/scoops....you know, almost everything) I can start power testing again.
Dave Leonard is the one to seek out for heat issues, like controlling radiant heat from the turbo. I'm working from his kind critique of my project, and I'm shamelessly copying his chin radiator set up. I'll be adding some form of reflective barrier on the inside of the cowl, and additional heat shields around the fuel system etc. as required. You are right to be concerned about heat close to your primary flight controls.
As for Dave's modest comments on his 'thrown together' air scoop for his radiator, I'll note here that he experienced no loss of speed or increase in fuel consumption. That is evidence in it'self that he did a good job, Plus: I just got a Boeing Frontiers magazine that shows an unmanned delta flight body that has the identical scoop, albeit on the top, to feed the engine. I think his scoop is closer to optimum than he realizes, and I'm going the same route.
Scott
-----Original Message-----
From: John Slade <jslade@canardaviation.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sun, Sep 6, 2009 6:42 pm
Subject: [FlyRotary] Re: Regarding Scott Emery's turbo manifold
> Is there a conventional wisdom as to when to use a waste gate.
Chris,
My wastegate is automatic. It takes a vacuum feed fro the intake manifold and cuts in and out automatically.
John
Chris Barber wrote:
> Scott/Group,
> > I was just looking at the turbo set up that you posted. > http://gallery.eaa326.org/members/semery/?g2_page=1 Thanks for posting.
> > It looks great. It is continuing my motivation to pursue the turbo. I > also have the Conversions Concepts mount. I too will likely have to > fabricate - read that as have fabricated since, contrary to my manly > man status :-), I know not how to weld :-( - my turbo manifold. I > like how clean and simple yours is.
> > I am trying to decide the best position for it. The current extension > that I have on my engine - in order to clear the Mistral Injectors > location puts my aftermarket turbo manifold perilously close to my > aileron control linkage (about 3/4 of an inch, or so). Also, it is > right up on the top of the cowling.
> > My question to you is, I did not notice a waste gate mounting place on > your turbo exhaust manifold. Both my aftermarket manifolds have a > place to mount a waste gate. Did I miss it, is the wastage internal > to the turbo? which I think is how Mazda did it, but figured this was > not the case with the larger T04's we seem to be using). Where might > I add one to a manifold I would have made. Would the position be > secondary to just putting it in the place with most clearance?
> > While I have learned a great deal about how turbo's work, I am far > from versed enough yet. Is there a conventional wisdom as to when to > use a waste gate. I thought they were standard and the primary means > to control boost, along with a pop off valve (if that is the correct > term and idea?)
> > Advice and insight is sought and appreciated.
> > Thanks in advance guys and gals.
> > All the best,
> > Chris
> > Cpl. Christopher Barber, JD
> Badge 330
> Bellaire Police Department
> 5110 Jessamine
> Bellaire, Texas 77401
> > 713-668-0487
> 713-662-8289 fax
> > CBarber@BellairePolice.com
>
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