[E4ODnut]

"Turning off cylinders" is getting beyond what I am comfortable tuning with. I would think that simply cutting off fuel won't do a great deal of good unless you can also eliminate the pumping losses with some sort of inlet and/or exhaust valve control.

The engines I work with are relatively low tech with stock configuration. My philosophy is one to just try maximize what I've got, tuning to the degree in which I am able to do in real world situations. I just go with the theory that any throttle setting that results in about 80 KPA of manifold pressure or less is "cruise" and I'll run as lean as I can without any sign of lean surge (idle range excepted). For my engines this is about 17:1 indicated. After about 80 KPA I feel that I am requiring some serious power and ramp up to about 12:1 at 100 KPA at max HP RPM. This is just my view on things and what I feel comfortable with. There may be a better way.