[Roadsters] AIr flow - Datsun

[Jim Gammon]

Just a comment on the science of flow, which is what I do. (Hydraulics and gas or air flow aren't very different)
   
  The secret to low pressure drop, which means the highest flow rate in a set system, it to not change velocity, and if you must, change it gradually. 
   
  So when you port or or modify air flow in or out of your engine, to get the max flow you need to calculate the area of flow and keet it constant. 
   
  For example, if you take a cross-sectional slice perpendicular to the direction of the flow path every 1/8" and calculate the area, it should not change. If it must, a reduction should be gradual, but may change fairly quickly. An expansion must be much, much more gradual. Otherwise, you get turbulance, and less flow. 
   
  If you want to know the actual math, emal me off list. It requires a lot of math. In essence, the accelleration or decelleration must be constant.
   
  JimG