Here is a site that calculates speed, thrust, horse power . It may have been posted here before. With my nelson data it gives speed at 162 mph and i measured it at 163. Pretty close. Looks like i need more pitch. 9 = 181mph ; 10=201 mph. My thrust is low with the 7.4 inch prop which explains takeoff difficulties. If the jett 50 swings a 9x10 at the same rpm that would be much better. I am going to put the jett fire 50 on the new whiplash as soon as it gets here. Will post results.
http://freespace.virgin.net/barry.ho...e/goodies.html