ddunbar wrote:

 Hello Paul,
 For aircraft use I ask this question.
 What are the pro's and against of putting the throttle body before the
 turbo compressor.
 Mazda uses the 3 throat body for control of low down torque and
flexibility but
 a fixed pitch prop is quite different.
 What are your thoughts on this.


 --
 Best regards,
  ddunbar                          mailto:ddunbar@echidna.id.au

Good question Don. Hugh MacInnes's book "Turbochargers" HP Books
suggest putting the throttle between the compressor and engine
to prevent a vacuum on the inlet side when the throttle is suddenly
closed at high RPM. That could suck oil out of the turbo and into the intake
system past the seals page 23 and 24. On page 103 there is an aircraft
diagram with the carb on the outlet side. That is where I am planning
to put my slide throttle. However most of the
diagrams in the book have a carb on the inlet side.

A three throat body will have more intake manifold pressure loss
than a one throat
throttle of the same area. Make it big and make it clean and simple simple.

Paul Lamar

   A slide throttle is not a good idea, the intake vacuum will pull on
the slide so hard that it will stick the throttle, done it did it
been there.

  Ken Welter

Very true Ken so it must be engineered with that problem in mind.
This one works like a small car with four small ball bearing wheels
that allow the throttle to move back and fourth in the housing
regardless of how much force is on the throttle plate.

These wheels are known as cam followers.

The slide throttles used in race car engines generally have recirculating
linear ball bearings. That was too hard for me to fabricate  so I came
up with this idea. I need to do a 3D on this as it is a bit hard
to follow this drawing.

Paul Lamar
 
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