and yeah mav thats why the tj-100 installed actually performs exactly the same the p-60 in the A-4, sometimes even better pending on the turbione build weight. it has lighter weight for its installed power. you can have 400 pounds of thrust to a 10 pound thrust fan, but if takes 399 pounds of motor battery weight to get it your no better off, and even worse at slow speed part throttle cause that big pack to post big numbers is all still there at slow speed. But if you want to borrow terminal velocity for high speed runs the weight is handy! other wise most physics equations will tell you your lucky to get 80 percent of your efflux in velocity, and thats if ya got a clean airframe. but archimedes tells us a lever can amplify our work load, so if you borrow terminal velocity as a lever you can always stretch the truth as well! lol