Al, in many of the induction articles I have read, I frequently come across velocity flow numbers of 300-400 fps.  Some caution not to exceed airflow of mach 0.6 in the inlets.  I'll find some of the articles for you to read, it seemed high to me as well, but I ran across it in a number of different articles..

 

Ed

 

 

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC

 

Now your getting hotter.  High performance normally aspirated engines have peak intake tract velocities measured in mach numbers (.6  is a good number).  The term "peak" is a key factor in understanding how and why it works.  Another key is to also realize that the minimum velocity is in negative numbers! 

 

Al, focusing on the losses at these velocities and thinking that re-accelerating the column of air in the intake tract is a bad thing misses the point entirely.  That's like saying a supercharger will drop horsepower because it takes power from the engine to turn it.

 

Now its my turn to wonder if this ruminating is helping or confusing.

 

Tracy