I believe the original question was about the IO-550N, normally aspirated.  25.6 to 27.3 is the range in the TCM SB.  But that's for a stock engine.  That number is only valid with stock pistons.  GAMI might be the best source for what fuel flow numbers are necessary with 10:1 pistons, 32 GPH.

 

Unless Fred gets some numbers from someone with an IO-550N with 10:1 pistons, he should ignore the other numbers in my opinion.  I'm concerned that all the numbers for the TSIO might be confused with Fred's original question.

 

Mike Easley

Colorado Springs