[alfa] Air boxes and resonance

["agiyo" <agiyo@xxxxxxxx>]

The Spica air box is a marvel, no doubt about it.

But for an absolutely trick air box, look at a TZ.  They are the epitome of
the '60s tuning fad (which is not to say it might not work) of megaphones and
cones and reverse cones etc.  Someone very educated worked a long time
figuring out what to make a positive cone, what to make a negative cone, and
how to bounce pressure from the back of the air box to the carbs at exactly
the right time.

Articles appeared in "Cycle" magazine IIRC, probably by Gordon Jennings, to
help motorcycle people figure out what angles and diameters to make exhaust
pipes for best timing of suck and blow (terms used loosely at the Institute of
Empirical Blunders).  Alfa did it for intake and exhausts, if I recall
correctly that GTA headers incorporated cones.  I've never actually worked on
one.

Doubtless some of you guys who actually know what you are talking about can
add to this.  I don't know what ever happened to the expansion chamber
theories; perhaps they just passed out of fashion, or people got too lazy to
make their own stuff.  And I don't know whether TZ air boxes have air horns
inside, like Spica, in addition to being double reverse cone megaphones and
who knows what else.

Peace,
Joe Cantrell
Wet Portland, where our AROO Pres. totalled his sweet '74 GTV at track day
yesterday (he's OK) and my daily driver appliance was stolen last night with
all my tools, the Mustang Turbines for the Berlina, and assorted motorcycle
parts.  Et Cet.
'72 Spider PIR Slut (but not loose enough to go out on yesterday's owl snot)
'73 Berlina Gortimer, soon to be daily driver
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