So! That is the initial logic I decided to go with at the dyno.
To test the logic with _this_ engine, I decided to do a couple of runs to proof theory. One run with the valves left in the closed position and one with the valves in the open position. Easy enough to do with the Zeeltronic pv controller.
A few things seem to speak out here:
You might look at the above comparison chart and say "Simple - open the valves at 7912 RPM." and you'd be kind of right. While indeed the torque curves do cross at approximately that point, there are other things to think about. First - the electronics / pv motor can't react instantaneously (over a single RPM?!). Second: and while opening the valves as quickly as possible is likely an appropriate logic for say ........ an RG500 engine it likely isn't for the Yamaha spool type power valves.
It was a mistake to start opening the valves at 5500 RPM. Look at how the torque curve for the pv closed run (blue) is above the base line run (black) until about 7300 RPM. That says leave the valves closed until about 7300.
I was closer on having the valves fully open at 8500. We'll say 8300.
For the rest of the testing the valves were programmed to start opening at 7300 and be fully open by 8300.
Note: There is an anomaly on this chart. Why does the pv open run measurably stronger (almost 3 HP) above 8300 RPM when all other conditions were as much the same as I could make them? Hmmmmm.
next post ....... Ignition Curve Testing