ORIGINAL: HighPlains
You need to do a little more research on the concept of prop efficiency. I’ve seen it referred to on RCU quite often, and almost all have it wrong.
My first post was a combination of facts and theory so maybe I should have put in a disclaimer. You must remember that I used the word "predict 201 mph" and not will go 201 mph so that should have given it away. There is no way to know all the exact facts but I still predict the engine power and gravity will allow up to but not much in excess of 200 mph with a 9x10 prop. Time will tell.
I was a pilot and not an aeronautical engineer so I do not have all the answers. I do try to back up what I say by explaining my reasoning and point to reputable web sites that support me. I was hoping to learn something in this thread but those with more knowledge then me could elaborate on why I am wrong and not just tell me to go do more research. At least point me to a web site that contradicts me. There is usually a difference between theory and reality so the real test will be the radar and Doppler #'s.