Posted for "Douglas Brunner" <douglasbrunner@earthlink.net>:

 Recently, I installed two aluminum cowl inlets (see photo) in my Legacy.  I
did this largely for aesthetic reasons, but also expected that it would
improve my ram air pressure.  I was wrong - for reasons I don't understand my
ram air MP is now less that my filtered air MP by a full inch.  (My ram air is
reversed because my plane had de-ice and the de-ice alternator is on the left
side).
 
 I have sketched a new ram air system that I hope will give me back at least
1.5 or 2 inches of ram air. (see sketch).  Features:
  1.. The ram air inlet will be flush with the cowl inlet and well out into
the air stream.
  2.. A "flapper valve" to block the filter when not in use
 Your thoughts?
 
 Any suggestions of who could fabricate this?