I have not dynoed mine, but on the track (straight line), it is as fast as a track RD350 YPVS. Similar bikes to this RD have been dynoed at approx the same power as you got. 52. So I guess mine, std 21 with wire splice, is also on this range. I guess next step is open the airbox and rejet (4x 1 in holes?).

Now, question for the experts. Andy is explaining how to reach the 60 Hp range with wire splice and airbox mod. However, Tyga's way to get there starts with wire splice and new expansion chambers. Are these two ways compatible? What would be the outcome of both mods? Which one to select first?

I know there is a lot of knowledge required to fine tune a NSR, and of course there are no hard rules that can be followed. This is just a question from a non highly skilled person to start planning enhancements on his 21.