Hi all, wondering higher or lower Kv for control line stunt ?
High or low depends on how you hold your mouth. You should size the system so that when the battery voltage is hovering around 3.3V or 3.2V per cell and you still need lots of poop in the overhead 8 and the clover it's there. For a fixed-speed setup (Hubin & KR timers) you want your set speed divided by Kv to be about 75% of your nominal pack voltage (meaning, pack voltage computed at 3.7V/cell). For variable-speed setups like the Fioretti and Burger timers you want more (because they ask for more speed when the airplane is on top), but I'm not sure how much.
If that works out to "high Kv" for you, then you want "high Kv". If that works out to "astonishingly low Kv" for you, then you want low Kv.
You probably do want a higher cell count for a motor than is typical or recommended for RC -- the recommendations for motor/prop combinations in the catalogs assume that at some point you'll nail the throttle to the top of the transmitter and bore holes in the sky. With a typical top-level competition stunt setup, this would burn out the motor or ESC. It works for us because the timer/governor combinations we use keep the motor from running at full throttle until the end of the flight, when the battery is starting to go flat.
If this is all making you want to scream and run around the room bouncing off the walls, just look in the "list your setup" thread, and pay attention to the timer used, the number of cells, and the Kv of the motor. Then copy something that works.