I haven't found a winner take all yet. Neither have others that have expended a lot of time and fluid engineering on the problem. The 3w method of routing the tube into an air intake seems the most consistent, but not always. Toms' method works with about the same percentage as the one from 3w. The balsa box is the cheapest, easiest way to try getting a handle on the problem if an air pressure deflector did not work. Start easy and cheap and work up is about the best one can do. It's a royal pita when methods don't work.