>
> Now a set of K&N filters will allow more air per unit time to flow, but
> they cannot increase the oxygen content of that air (can they?). If the
> amount of oxygen is the same as for stock filters, then why do we need a
> richer needle? In fact, why manufacture more than one needle per carb
> size, since the needle's only purpose is to maintain a stoichiometric
> ratio of air & fuel, which ONLY depends upon the sizes of the respective
> orifices? At high altitudes, you may raise the jet a bit to compensate,
> but the needle profile shouldn't change, should it? Isn't stoichiometry
> sacred?
>
> --
>
> Todd "A little knowledge is a dangerous thing" Mullins
> Todd.Mullins@nrlssc.navy.mil On the lovely Mississippi (USA) Coast
>
> '74 MGB Tourer with twin HIF4s
>
> "I could go at any time..."
>
Good Afternoon,
Yes Virginia, stoichiometry is sacred. Opps, excuse me that was Todd, and what
would you like for Christmas?
So, the system is dynamic. We have nonlinear air flow, pressure drops, and other
confounding sonic effects to deal with. The pressure drop across the filter
effects
density and flow which affects mixture strength. We also have sonic phenomenon
that
are affected by headers, and intake configuration. The composite physical
manafestations
of these effects are manipulated by cam setup, valve size, and port
configuration to
give optimal volumetric efficiency at the desired RPM. This moves the power
curve
up and down the rpm range as desired.
Scarey huh!?
If it wasn't for all that crap a single needle and jet would be sufficient.
Would someone please pass the Kim Chee.
Cheers,
Ken Boetzer
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