Posted for "Bryan J. Burr" <bjburr@mwheli.com>:

 After talking with Andy the plenum makes a more efficient use of the
 cooling air.  Then inlets can be reduced thus eliminating drag.  The
 greatest benefit is to eliminate most of the sheet metal and baffeling
 material, reducing cylinder head temps and oil temp, without reducing
 power.
 
 I am proceeding to the design and production stage on this for my ES.
 Should be the same as a IVP as the cowlings are the same if the TSIO550
 is used.
 
 Bryan

 >    any idea what the performance improvement is for adding that?