I have read up on the ram air/ram jet of NACA times, and how its really only useful at supersonic speeds. my question basically is for clarification because I honestly don't know how to work the math out to really figure out how beneficial it would even be. This pertains to drag racing. I have a motorcycle and currently trap around 135mph at the end of the track, so i would make more use than most cars. Basically I was trying to figure out, if i had a cone inlet, say 7" in diameter that tapers down to 4" in diameter over 1' length linearly, would I see a notable increase in air velocity? at 100mph, if my manifold vacuum is say 3.5" H2O, how much less vacuum would I have, or would I possibly even see a slight presurization with that same cone? this question is benefical for me because as we go faster we experience more drag, our acceleration rate slows, and we plateau. If i can raise the plateau, even slightly, it would be great. something to counteract the drag, i.e. more horsepower.