the only reason Ed and I are skeptical, is that we currently run Nelsons on smaller, cleaner, and lighter q40 airframes with a nelson turning closer to 24,000 rpm and see straight line speeds around 185 mph.
Dave,
You have that right. look at the amount of work we have to do to get those speeds. If 200 mph was that easy we would be carving wood props and doing it! 30% fuel does not make a huge difference over 15% fuel as evidenced by only 21k. 200mph at 21k using an old stock racing .40 in a 5 pound airframe? It just ain't so.
Ed S