Scott writes,  "At 183 KIAS I should be seeing about +1.5" Hg added to the MAP because of a dedicated ram induction port."

 

And I too "should be seeing about +1.5" Hg added to the MAP because of a dedicated ram induction port" but I clearly am not.  My ram air port now adds only .25 to .35 inches of pressure and I don't understand why not more.  Clearly, the consensus of our builders and fliers favors the installation and use of ram air ports in our Lancairs. 

 

As I understand it, the worst that should happen after I remove the ram air is that my aircraft performance should be no worse than it now is - and that is a happy event!  Like you, I am capable of flying at 183 knots using just 90% of my available power (long wings, 0360, after-market injection and electronic ignition).  More often, cross country flights are at 12000 feet and 175 knots cruise.  I love it!

 

Removing the ram air should reduce weight and complexity while facilitating maintenance (cowling easier to remove & install), streamlining the cowling and permitting better sealing of cooling air.  The experiences of others have varied but, for me, the only downside that I can see is a theoretical reduction in speed/power at high altitudes and airspeeds (but not on takeoffs, landings and slower airspeeds).  Are there other safety or performance factors that should be considered?

 

Thanks to all for your comments.   Greg Nelson