here's what i had last year, before engine mods:
- 44.6 rw hp
- 30.7 nm torque
graph is here:
http://forums.sohc4.net/index.php/topic,134863.msg1522043.html#msg1522043that's pretty good as honda claimed 50 hp at the crankshaft, and many sources quote 38 rw hp for a stock 550.
after the current engine mods:
- 54.1 rw hp
- 67.9 nm torque
that's an increase in horsepower of about 22% and torque of 121% (!) compared to last year.
spark plugs and airfilter had about 8000km on them when measuring, with fresh ones it may be a tiny bit better.
here's the final graph:
the bike pulls like a train right from the start and keeps reacting strongly to throttle input through a wide rpm range. the power distribution seems very usable. does not peak as high as it could with maximising high-end output but for use on the road, this seems very good - apart from the theory that's also how it feels
we also tried the uni filter NU-4055 that fits in the stock airbox, vs. the honda OEM paper filter (with 8k km on it, so not totally pristine):
at higher rpms the unifilter provides less airflow than oem, shown in the dropping air/fuel curve. this manifests itself in a lower power output. this seems contrary to what some people claim - but these numbers don't lie and i'll be sticking with the OEM paper filter.
we then experimented with taking off the cover (mine has that "snorkel"), off the airbox: also that did not improve anything, neither flow nor power.
RAF i need to go now but will post a summary of the mods.
finally, the man i need to thank most is mike rieck.
over lengthy email conversations he patiently listened to my needs and ideas and helped with excellent advice to come to this result! that of course is on top of the brilliant work on the head that he did himself.
