Originally Posted by
Nitrovein
Using that a 14x6 APC at 10,000 RPM increased to 10,200 RPM. RPM increased 2%, thrust 4%, and HP 6%. For 10,300 RPM the thrust increase 6% and HP 9%. These are rounded of course. But just a 3% increase of RPM increased HP almost 9%. You won't be able to tell this on a bench run, but when flying a plane I can tell a 300 RPM increase because it accelerates faster and climbs faster, it is noticeable without measuring times or acceleration.