Charge-air temps are EVERYTHING.  The flying rotary turbo guy should measure his. As you might imagine, 30-inches of MAP at 80F degrees is not at all the same thing as 30-inches of MAP at 140-150F degrees.  That's a pretty typical output temp for a well-matched turbo.  So yes, intercooling is a MUST. 

Speaking of temps, I meant to ask about the calculations.  What would be the theoretical loss of available power between 30" MAP at 90F, and 30" MAP at 167F?  I attempted to calculate this, and came up with only having 88% power at 167F compared to 90F.  I'm only about .0348% confident in this calculation though.  It sounds like Finn is seeing a much larger difference, and I've always been able to feel the diff in cars between hot and cold days.  To feel the diff in a car would seem to suggest quite a bit of power to me.