flyrotary@lancaironline.net Mailing List Archive

I recommend that you get the book Maximum Boost by Corky Bell if you want to know all about turbochargers, including wastegates.

See http://search.barnesandnoble.com/Maximum-Boost/Corky-Bell/e/9780837601601

You really need a wastegate and it is external to the TO4. The wastegate should be mounted in the exhaust manifold before the flow gets to the turbo. It controls the exhaust pressure and, when necessary, allows exhaust to bypass the turbo to control the amount of boost. The pop-off valve is on the intake side and serves primarily to protect from over pressuring the system when you rapidly close the throttle. This should not happen in an airplane, but it does not hurt to have one (other than extra cost and slight extra weight).

Bob

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Chris Barber
Sent: Sunday, September 06, 2009 8:06 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Regarding Scott Emery's turbo manifold

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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