View single post by James Sohl
 Posted: 01-06-2011 08:24 pm
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James Sohl


Joined: 04-24-2006
Location: Chandler, Arizona USA
Posts: 18
The slight increase is likely the result of the airbox acting as a plenum chamber.  I am not aware of the air flow capacity of the stock air filter under standard conditions, however I doubt it is very much different than individual filters, despite the obvious differences in appearance.  I have read that the Lotus Twin Cam engine was designed for use with a plenum chamber and that, at least with Strombergs, no performance increase should be expected by a change to individual filters.  I will try to find that statement.  Many modern street engines and most modern un-boosted race engines are fitted with plenum chambers.  A plenum can be fitted either before or after the throttle plates, although usually before.  I'm not aware of a use of both locations on the same engine, but it would certainly be possible.