[Vwdiesel] ECO -- VW ----( Hagars ECO -- Bunny Bondo )

[slatersfb at aol.com]

Check out the long intake runners on N/A motor. These are a tuned length to create positive wave pressure at the time intake valve opens. Wave tuning actually stuffs incoming charge into cylinder, rather than relying on vacuum to suck it in. 
Waves are created in runner when intake valve slams shut on incoming charge, and another when intake opens. These waves travel backwards, up through runner and are reflected back down from the open end. The length of runner determines the rpm at which the positive wave arrives at intake valve opening.
N/A two stroke motors barely run without wave tuning in the form of an expansion chamber.
 
Bob 
 
 
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And opening that intake
valve at 5 psi overpressure is different --- than opening it at a slight 
underpressure.