Ok, I hate to sound dumb here, but this chart is way over my head.  I'm
   sure it provides everything I need to know, but I don't know what
   questions to ask of the chart.  To start, is there a problem with the
   displacement shown on the turbo spreadsheet?   The spreadsheet says that
   the 13B displacement is 159.6 cubic inches.  That sounds way to
   high.  I
   looked up the displacement in "cubic centimeters" and converted it:
   13B = 1308 cc =  79.788 cubic inches
   20B = 1962 cc = 119.682 cubic inches

   I'm in Dallas and do most of my flying in 90-100 degree F.  My field
   altitude is 600ft.  I usually fly under 15k altitude.  I just want to
   know how to select a turbo that will help me maintain 350 hp up to about
   18k altitude on those hotter that hell Texas Summer days.  Can anyone
   give me the "Cliff Notes" or "Turbos for Dummies" version
   Don

   No Don it is indeed 159 c.i. equivalent. The three rotor is 240 c.i.
   roughly. That is how much air they pump in one rev at 100% VE. I
   am not sure which spread sheet you are looking at but it is probably
   Dave Leonard's. Can you help Don out Dave?

   You will also need that Turbochargers book Don. I hope you save
   messages :)

   Paul Lamar


Eh yeah, Im not going there... that is too close to the old "is it a
4-piston, 6-piston, or 2-piston equivalent?"  :-)

Lets just use 159 c.i. and leave it at that  :-)

(ok, each chamber is used once per rev instead of once every other rev
like in a typical piston engine... so double the equivalent volume)