Perhaps an RCR is in order where we specify that a ram air appearing intake must prove via data that it is not boosting air pressure in the intake above atmospheric. I've never logged a motor with a restrictor before, that may get interesting. I imagine it drops a bit more as it approaches redline or else the engine wouldn't make less power. It can really get messy in the case of a gutted LS1 airbox because again, they are restrictive in stock form. Even without a restrictor you are going to see a pressure drop as you approach redline. Now if gutting the box decreases that pressure drop, it won't necessarily be because of any ram air effects. The mere act of relieving a restriction in the intake tract, which is what this does, can absolutely decrease that pressure drop approaching redline. Some ram air systems do just this. They don't boost above atmospheric, they can only help with the pressure drop. A good free flowing intake that isn't bothered by packaging constraints can perform the same if it is fed cold air. So how do we as CMC define ram air? This is a loaded subject where a guy could get screwed over at nats by trying to have a cold air intake but, as long as someone has money and perceives that he is looking at a competitor's ram air setup, can have him DQd depending on how the directors perceive the intake to perform. Here's my thought: if the logged pressure drop is less at the top of 4th gear than it is at the top of 1st, you're getting some benefit of ram air. This is the only fair way to police this, and is what a racer should be doing to protect themselves before fielding such a system.