Frank- My box DOES have a lid- the bottom of the gas tank. The only time it doesn't have a lid is when the gas tank is tilted up. I was looking at the box purely as a conduit to move air. As far as the shop vac idea, we would need to hook up a pressure manometer to the air box and see what positive pressures occur at what speeds, and duplicate those readings on the shop vac dyno. I don't think that I am smart enought to figure out how to make variable speed shop vacs that can be controlled as fast as the engine can accelerate the drum on the dyno. I am just going to settle for the concept that the ECM richens the mixture in 5th and 6th, so if I can get it to run right on the dyno in 4th, It should be close. The final high speed tweaks would have to be made under a controlled situation with stable weather where you could make a number of top speed blasts with a GPS unit taped to the bike.