Rocketman612 ,

Sorry for the slow response. I'm flying the 91FS/12-8 three blade ar about 9300. It peaks about 9600. For the way I fly the plane, it's enough power. I can get fairly large loops and decent vertical for humpty-bumps so long as I don't try to roll on the uplines. I can get a vertical 8 out of it but it isn't too pretty. That would probably be better with a Saito 100. I had this engine already. If I was buying one for it, I'd think about the Saito.
The Delta Vortex isn't real fast as deltas go. Large thick wing, gear in the wind, servos hanging out, lotsa drag. But it sure looks cool touching down with the nose up in the air and flying aerobatic maneuvers.

Larry