The hot pipe deal sounds plausible, I have heard of that before come to think of it. You may think I am lying, or exaggerating, but I have to set the needle about 2000 rpm rich to cover the unloading in the air. I launch at around 19,500, with the engine then climbing to the full rpm once unloaded. I can peak it to almost 23k on the ground, but it will not make the climb out before it starts to sag. I guess the whiplash's airframe allows the engine to really unload. I have never had a flame out, and it is very very easy on plugs.
Thanks