I thought i was diled in but i think i need some suggestions...4.25 pro running a 19p ballistic with cup added at 6300rpm 46mph consistently ...broke 50 a few times on long flat runs but I seem to over rev when turning...i do trim down in corners but if I go too far the motor seems to have a spot that halfway between full trim and no trim it cavitates bad and i can't run at that trim ..either higher with a rooster tail and runs great and overrev in corners or lower and pass through that cavitation area every corner which is rather annoying. Steering is also stiff as soon as it passes a couple trim bumps. Would going to a 21p in the same prop not cavitate as bad because it's going to lower my rpms? Should I try a prop with more cup? Is a spitfire x7 in order to fix it $$$...id like to see the same speed and the ballistic was supposed to be the "it" prop with the lower price tag according to my prop shop...if I was running long straight runs imo this prop is great other the the weird cavitation area you have to trim through.