Posted for John Huft <aflyer@lazy8.net>:

 Walter, I appreciate your concern. Of course, I have no way to measure the
ICPs. I simply follow Lycon's advice (they built the engine) to run at least
150 degrees rich of peak at high power.
 
 All, I am not advocating this system for your turbo engines. The original
question came from a 320 builder, whom I assumed was naturally aspirated. When
I race, I just use the filter (valve closed) for the taxi phase, in the dusty
conditions at the big fly in, and when the starter is counting down, I open
the valve for takeoff.
 
 Even if you always do this to address the concern of high temp intake air
causing detonation, you would still enjoy filtered air when taxiing, and
waiting in line at Copperstate, and automatic alternate air at all times.
 
 I had no idea I was opening such a can of worms with my original post. Back
to lurk mode.
 
 John