George:

I have two (2) SPT5 turbines. They originally came setup from the factory at 165.000 rpm but my dealer told me to bump them up to 170.000. That 5.000 rpm difference really made a change in performance in my planes.

Both are equipped with Biela 24 x 12 x 3 since the airplanes didn't performed well with the 25 x 12 x 3. I do think that Boli also runs a 24 x 12 x 3.

I have limited the propeller rpm to 7.400 rpm but in flight you rarely see rpm's going higher than 7.100 or 7.200 rpm.