I'm confused...  to get our air pumps, (oops engines) to run as  
efficiently as possible, we strive to make the air path into and out of
the engine as free as possible..  the freer the airflow the more air we  
can pump (more RPM) but if we are RPM limited by prop tip speed, why    
spend money on headers and tuned intakes? heck, turbos are very
restrictive, yet they DO compress more air through the engine at a fixed RPM.
 
why would someone spend $$ on porting or Chuck's beautiful headers to
have the same max RPM?                
  
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Utopian Maturity: Eternity, Liberty, Equality and now Fraternity & Altruism.