In the same spirit of friendly ribbing, the factory liked that 340 so much that they replaced it with a turbochrged Rotax.

I kid as well; they use those planes as test mules. Removing the 340 is not an indictment of its performance. How many engines has 12KF had? Nonetheless, I don't think anyone would say the performance from the current powerplant on the STI is Prius-like.

jmodguy, your plane will be a beast, and a pretty one at that. What's great about building your own plane is that you get a plane that is really your own.