You should have seen my Tiger 60 with a Dinamax fan unit and a OS 91 and pipe mounted on top, in flight it looked like one of the German rockets from WW2.
I also kit bashed a North Star with the same Dinamax fan unit on top, a storm came through the area then, I took the opportunity to fly it that day, strong winds, flying into the wind took a long time but flying down wind was fast as a jet, good experience before my waiver.