I'm running my SF260 in the 320hp range, but I am not sure what prop variables to tweak in order for it to properly absorb that extra power. Does propeller_blades=3 actually have the dynamic effect of adding a third blade? I've also thought about just increasing the prop diameter number, though I don't know if there is a better way to go about this. Any ideas?

Try changing the "thrust_scalar" in the a/c config file under the "propellor" section.John