1) You are confusing plenum volume and flow rates.

2) I'm not a mechanic. Not sure where you got that impression.

3) I thought Area Six had done all the development so you shouldn't have to open it up and change air horns?

4) You have a fair point on being able to change the manifold entrance around.

5) Are you saying that the runner angle of aproach or the runner taper is optimum at 15 degrees? No need for the lecture on harmonics. The assumptions about runner length are not always correct. It depends which harmonic the runner lengths fall into.

6) You are paying through the nose for Jenvey parts that are not needed. A skilled fabricator could form those parts from sheet for a fraction of the cost. I stand by my figures. If i had to make a batch of five similar inlets i would be happy to sell them for £250

7) No one has identified the design flaw yet!