SNIP:
   ...........I turbo normalize plus (make moderate gains in power at S/L
   through use
   of the turbo then 'normalize' that amount of power for benefit at
   altitude).  I achieve that by use of the throttle.

   I have a fixed waste 'gate' (exhaust bypass really) because it was the
   easiest way for me to get a big wastegate.  I believe an aircraft style
   wastegate is an excellent choice, but a LARGE automotive style can work
   equally well and is more available and less expensive.

   David Leonard

   Turbo Rotary RV-6 N4VY
   N4VY.RotaryRoster.net <http://N4VY.RotaryRoster.net>
   <http://N4VY.RotaryRoster.net>
   www.RotaryRoster.net <http://www.RotaryRoster.net>
   <http://www.RotaryRoster.net>
   leonardiniraq.blogspot.com <http://leonardiniraq.blogspot.com>
   <http://leonardiniraq.blogspot.com <http://leonardiniraq.blogspot.com>>

   David,
   Again I apologize for my ignorance, but can you explain exactly what you
   mean by "fixed wastegate"?  If I understand the term "fixed
   wastegate",  its basically a wastegate that is always open a little to
   allow a constant leak?  That would also allow a constant percentage of
   the exhaust to flow into the turbine side of the turbo.  If that is
   correct, Why use a "wastegate" at all?  Why not just have a small
   port before the turbine that leaks exhaust around the turbo and back
   into the exhaust pipe?  I guess a set up like that would require some
   sort of trial and error getting the % of exhaust bypass correct.  Maybe
   some type of restrictor in the bypass port?   But you would have much
   control of the turbo that way!!   Is that why you use a "fixed
   wastegate"?  So you can adjust the amount of bypass?  How does that
   differ from the normal wastegate operation?  I thought a wastegate
   cycled from open to closed based on its duty cycle.  That's different
   from the fixed wastegate isn't it??  Damn I'm confused!!!!!   Also what
   do you mean by, "then 'normalize' that amount of power for benefit at
   altitude).  I achieve that by use of the throttle."  I didn't follow
   that part at all.
   Don


Don, you are right that it is not a wastgate proper, but a bypass
port..  it used to be a wastegate until if removed the flapper valve.
Why? Because it was creating more back pressure than necessary for the
boost I needed - even with the flapper in the full open position.
Nothing fancy, I just hacked it off with a dremmel.  That opened up the
exhaust flow quite a bit.

There is still enough exhaust energy to get me about 10 psi boost (about
50 MAP) at sea level but I never use more than 5 psi. (that is the plus
part).  at 10000' I still have over 30"MAP available (that is the
normalization part).  Just like anyone else, I just control my MAP by
using my throttle - there is nothing else to control except mixture etc..

Not the most optimal set up, but not bad either.  Cheap, easy and
effective.  The opening does not have to be exact.  The preferred method
would be to use a much larger turbine housing and an operative
wastegate, but that is difficult, expensive, and most of all - won't fit
in my installation.