Bob,
That is a really good job on the filter inlet!
I saw one of those alternate air valves somewhere, maybe here.  I mentally rejected it because it takes air from inside the cowl.
I was considering building a valve that would manually switch between alternate and filtered air, but after thinking about the inputs from Ed, I am not certain that it would be necessary.  A high flow filter that gets ram air pressure like your install should be fine.  I might put a large opening screen at the opening to prevent something like a bird strike from plugging it.

Bill B


Subject:
Re: [FlyRotary] Intake CFM air flow
From:
Bob White <rlwhite@comcast.net>
Date:
Sun, 3 Jun 2007 09:52:57 -0600

Hi Bill,

Here is one shot of the air intake.  There are some more at
http://www.bob-white.com/album/main.php?g2_itemId=532

There is one piece missing from the photos.  I didn't connect the air
filter directly to the throttle body.  There was an alternate air
source that added several inches to the length.  The last photo is a
picture of the box the alternate air device came in with the P/N.  It
was broken, and I threw it away.  I attached a picture of a similar unit
that I found on ebay (item 160048910751).  I never tested this to see
how effective it would work.

Bob W.