Caveman tech. Some years ago I bought a jet boat. I noticed many similar machines with the scoop mounted backwards. [S I started asking questions. The explanation?
- To avoid sucking in water and hyrolocking the engine. (That makes sense).
- No noticeable difference in performance. I didn't believe that nonsense. So I tried mine backwards and I couldn't tell any difference either. I did not have a/f readings to compare, strictly a seat-of-the-pants experiment to satisfy my curiosity. I would expect the backwards scoop to cause a rich condition and sluggish performance, but that was not evident in my experiment.
Logic. The engine got the air it needed either way. Like I said previously, a scoop doesn't change the properties of the available atmosphere, it only makes it immediately available. I do believe facing forward guarantees that and I continued to run mine that way. Better pushed than pulled.
I read someplace that the ram air effect occurs at well over 200 mph. Only then do you actually begin to compress the air and elevate the atmospheric pressure. Then you have force-fed air and definitely a lean condition just like a turbo or blower does. That's what I think I understand from it all, anyhow.
So, I'm as curious as you are. Please share those a/f readings when you have them. Again with the logic, I expect a difference, but I don't think it will be as dramatic as we would like to believe.