I just read the other couple posts on this.

Spiral airstream vs P-Factor. They are different.

The aerodynamics forum has guys running around that can clarify this stuff in their sleep. But they are probably not looking in this section of RCU....plus I just noticed the title of the thread is "Chipmuck". Too funny when the fingers don't type what the brain for sure knows!

The OP may want to append to a thread on P-factor over in aerodynamics; or start his own.

In the meantime....stay on the rudder!

Tom