Mailing List flyrotary@lancaironline.net Message #61
From: Marvin Kaye <marv@lancaironline.net>
Subject: Re: [FlyRotary]Re: Wastegates
Date: Tue, 17 Sep 2002 23:01:11 -0400
To: <flyrotary>
Posted for Ken Welter <rotary.coot@verizon.net>:

[What you need is a throttle-plate type wastegate like they use on the turboed Continentals...  Rayay makes a great one, about 2.25 ID, and it won't break your piggy bank if you just get the wastegate and deep-six the controller. You

   I made a butter fly waste gate for one of my race cars once and used a air cylinder to control it, I simply used a small spring and controlled air pressure on one side and put boost pressure on the other, if I put 5 psi on one side it would take 6 lbs of boost to open the gate.
   Ken Welter


[I've mentioned in the past that my approach will be similar to that used on the older turboed Pipers... the wastegate will be controlled by the throttle. The first half of the throttle travel will open the throttle body to full open.  Further advancing the throttle starts closing the wastegate and brings the turbo online.  Very simple, reliable, and proven.  Yes, you have to close the wastegate slowly to allow things to spin up... but I never had a problem in the Turbo Arrow or Turbo Saratoga with it, and don't see any reason why I should have any with my 13B using the same approach.  This way I'm not controlling boost (ie, your 5lb/6lb scenario) but controlling MAP directly.  I don't care how much boost I'm making as long as I can make the MAP I want. At some point I'll run out of boost, and that point will define my critical altitude.  BTW, I'll pop-off the intake manifold at 34" MAP.... reliability, reliability, reliability.  Comments, of course, are welcome and appreciated.

           <Marv>                  ]
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