What kind of speed can I expect from a Thunder Tiger 46 with tuned pipe with 9X7 prop running at 17500 on the ground? I ran it the other day while holding on to the landing gear and it felt like it was going to pull them off the fuselage. I was hoping for a little more rpm but this was all that I could get with this prop.

Hi!
Expect around 200km/h if you have it in a "Polecat" type pylonracer with wingspan of 135-140cm and a weight of 2,2kg and you use an APC prop (Which is best).

Regards!
Jan K
Sweden

My calculations show a theretical static prop speed of 116mph. But that does not take into account airframe drag or inflight unloading. http://www.altimizer.com/propspd.html