However, how is it that you can up the RPM limit of a given engine
simply
because you want to keep the prop tips subsonic?

You would decrease the RPM limit, not increase it, to keep the tips
subsonic.

Understood. If you lengthened the prop, you'd have to decrease the RPM
redline to keep the tips subsonic.

However, the part of the question I was referring to was if you *shortened*
the prop. Part of the original post implied that you would be able to
simply *increase* the engine's redline RPM if you shortened your prop,
regardless of engine limitations. I don't believe this is true.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"