Disclaimer: I have no idea what I'm talking about.
Just to add to the discussion, I made a video of the intake. I'm printing it now and may need to make some changes.
My philosophy with this design was to create a 4" diameter intake if possible and to keep the airspeed constant. By keeping the square area, and hence the volume of the intake consistent, I hoped to accomplish that. I dont think Ben's 3D printed intake took the same approach. His looked more like it was designed free-form, by hand.
This is a video of version 2. Version 1 was all done with solid modeling, whereas this new version uses surface modeling, and then thickens the part to create a solid model. Precise sketches are created for the actual shape and maintain the square area. Lofting is then used to smoothly transition from one shape to the next. In the end, I specifically transition to a 3.5" diameter round shape to match the SC inlet.
If you look at the lower right-hand corner of the video, you'll see the diameter and square area for each of the sketches that make up the intake.
https://youtu.be/8ElWbGIkLNc