If you are looking for a way forward here, I'd suggest some reading at Autospeed.
AutoSpeed - Technology, Efficiency, Performance
The proprietor, Julian Edgar is a fan of the Dwyer Magnehelic Differential Pressure Gauge and shows how to use it to size vents, ducts and airboxes, and intake and exhaust runners. Why you need a bellmouth in your plenum.
There's a lot there (768 articles) but a lot of it is on suspension, electronics, etc. For your purposes maybe
AutoSpeed - Building an Ultra Light-Weight Car, Part 2