Just a thought, but perhaps the problem could be solved by using smaller tubing for the MAP sensor input.  As you know, I work the Proprietary Software Systems AOA booth at the airshows, and we supply all the required tubing for the installation.  The tubing used for that instrument is a high-grade urethane with a really small ID.  I don't know exactly what that ID is, but I do know that the OD of the tubing is only 1/8".  The reason that small tubes work ok is that we are not looking at moving any volume of air through the tubes, all we want to do is transmit the pressure seen at one end to the other end.  Consequently, a small capillary does that job admirably.  Just a thought.

 <Marv>