re: Electric superchargers - BMW tried something similar **Rob

["Rob Levinson" <always_coca-cola@xxxxxxx>]

John G.Burns <john@domain.elided> wrote:

>Subject: Electric superchargers - BMW tried something similar
>
>All this talk of things in the intake tract remind me of
>something I stumbled across recently. BMW offered two
>airboxes for my 635CSi.
>One was the normal clear intake and the other, called a Cyclone,
>had a fixed cross shaped air deflector right at the front of
>the airbox. This looks to have been designed to cause
>turbulence in the air stream. I don't know exactly which
>models had it. It looks like a four blade metal propeller
>but is welded to the edges of the air pipe.



        Here ya go - April 1998, Car and Driver had a "long term test" on
the new 540i.  They installed the aftermarket device called the "Tornado"
which is practically identical to the Cyclone you're talking about.  This
device is popular among pick-ip truck/SUV owners who will buy *anything*
they see in "Truckin'" magazine.

    Here's the text of the Tornado part of the article:

"Baubles and  Bolt-Ons

    Engine- "Tell a Friend!" announces
the Tornado brochure.  "More Power,
More Mileage, Pays for Itself!"
    The Tornado is a sheetmetal fan
blade from Tornado Air Management
Systems (562-926-5000).  It mounts just
downstream of the air filter in the
engine's intake system, and it doesn't
rotate.  It retails for $70, plus $7 shipping
and handling, regardless of size.  The
theory is this: As intake air passes over
the fan blade, the airflow changes from
a straight flow to a swirling flow.  This
swirling air is supposed to atomize the
fuel better, making for more complete
combustion.  And better combustion
yields more power and better fuel
economy.
    We ordered a Tornado for our long-
term 540i and went straight to a chassis
dyno.  The guys at PowerCurve (810-
294-7700; www.powercurveLTD.com)
in Fraser, Michigan, hooked up the
Bimmer and performed two runs to
establish baseline horsepower and
torque curves.  Both runs were about
identical.
    Next, we installed the Tornado.  We
followed the manufacturer's instructions
to the letter.  Again, we performed two
dyno runs.  There was absolutely no
change in horsepower or torque.
    Our next test measured fuel
economy.  Using Chrysler's oval test
track, we circled at a steady 70 mph for
40 miles and recorded an average 25.8
miles per gallon without the Tornado.
With the Tornado installed, we recorded
the identical 25.8-mpg reading over the
40 miles.  So much for theories".

- - Rob Levinson
'85 535i Turbo ( a *real* blower)
'86 535i (naturally aspirated at 1 bar - I drink at many)

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