RE: speed motor recommendation
You will do well to follow Bob's recommendations with engine choice and direction. First off, you must commit to speed and have the bucks and willing to spend them. The BVM is with out doubt the best 90's size engine out there. They are still available on e-bay, were around $800.00 new, they should be good. The OS 91VRDF is a decent starter engine and will spin a 10 X 10 around 22K, still available from Tower at around $300.00. I have two of them from e-bay in the cabinet waiting for a winter build of something in the crazy area. Mine need to go fast and turn left well as local club pylon is my focus. The ability to Build and design well is a big plus in the game, but do not loose direction overall. You must also fly well. You can always find some old Q-500s around and stuff a 46 in them for practice. The more radical your design approach is, the better you flying skills must be. Remember, you must be able to repeat your run which requires landing in one piece. If you fly off a grass field, you can get away with no landing gear and pickup a free 10-20 mph or more. After reaching 150mph, 10-15 mph starts to come hard. If you fly off a paved field, its hard to keep them in one piece withoug gear. My current "crazy" will have a front retract cowled in with light wire skids at the wing tips and tail. I give it about 50/50 as to working out well. Its hard to retract without a lot of unwanted weight. If you get over 5# and want it to turn well, there are more problems to deal with. The "Jett engilneering" engines are he best bang for your buck, I have them from 35 to 90, all quite good. My lifetime favorite is (believe it or not) the BSE 35. Little sucker is now in its 4th year of raceing and getting stronger all the time. Last club race, took 3 of 3. You are restricted to smaller airframes here and if flying skills are limited, go to the Jett 60LX which is in a 40 frame. It will pull very well and is cost effective. If money is no consideration, go directly to the true jet aircraft. $10,000 will get you a 50# thrust jet, engilne, neat airframe and speeds well past the 200 mph limit imposed by AMA, just for the pushing up on the left side. May be cheaper in the long run. Regardless of your choice, ENJOY. Just my 2cents worth after over 40 years of good times with these things.