If I remember correctly; P mags are dual function magnetos, that replace the
current mags.  If memory serves me correct they are also  larger than Slick
mags.  The Lancair short mounts leave little room for the larger mags so I
opted for LSE.

Bob,

 

P-mags do generate their own power once above about 700 rpm.  Battery power is required for start.  The bulk is because the coils are mounted on the back of the unit.  Arnie had no problem with getting them in his short-mount 360.  He has been running his successfully since July and even raced with them in the Air Venture Cup.  Note that E-Mags would require aircraft power and, thus, a backup battery - just like our LSE units.

 

Being data oriented, I prefer to know what timing is being used - another plus for LSE.  Of course, we all know the fixed timing of ordinary mags.