Miata Mailing List: May 1994, Message #66
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   From: jwa@yog-sothoth.dcrt.nih.gov (James W. Adams)
Subject: Re: Weber DCOE update (correction)
   Date: Tue, 3 May 1994 19:04:42 -0400

Oops, the word "negative" below should be "positive" instead.  The
"negative" would apply to exhaust tuning, which works in ananalogous
fashion.  Positive pressure pushes a bit more air/fuel charge into
the cylinder, giving a power boost.

> 2) Induction ramming: The intake runner to each cylinder acts as an
> organ pipe of sorts.  At the right engine speed, the intake pulses will
> be reflected at the open end (or a plenum, as in the stock Miata FI
> intake manifold) such that a negative pressure pulse will arrive at the
                               ^^^^^^^^
                               |_should be "positive"

> intake valve seat just before valve closure.  This permits a slight
> additional charging effect, giving as much as a few percent boost in
> output [...]