Posted for "Jonathan Fuller" <jfuller@cox.net>:

"""
 "cblitzer" <cblitzer@triad.rr.com> wrote:
 I always thought that LOP, if one multiplies the GPH by 14.7, that will
 get you almost right on to your percent horse power.
 ------------------------------------------------------------------------
 ----------
 I believe that the multiplier is 14.2
 
 Robert M. Simon
 ES-P N301ES
"""
 
 My understanding (the source is the operating instructions on the Tornado
 Alley Turbo turbonormalizer available for review on their website) is that
 the constant for the IO-550 (with 8.5:1 compression ratio) is 14.9 hp/gph.
 The TSIO-550 (with 7.5:1 compression ratio) is 13.7 hp/gph.  This can be
 checked on your own engine by leaning to peak at the engine's max rpm and mp
 and dividing the rated power by the fuel flow.  If you accept the constants,
 you'll observe that your engine will make a little better than rated power
 when the air is cold and a little less when hot.  These constants depend
 most on compression ratios, but there is a little minor variation among
 different engine types.  Secondary effects probably include factors like
 camshaft profile and induction and exhaust characteristics.
 
 Jonathan Fuller