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Re: Armchair Engineering..

To: "John F Sandhoff" <sandhoff@compctr.ccs.csus.edu>,
Subject: Re: Armchair Engineering..
From: "Kyle Hagemann" <kyle@sonic.net>
Date: Fri, 15 Oct 1999 11:57:54 -0700

>Daniel asks:
>> At Shasta at the 510 show I noticed that a lot of the 510 guys had
>> a strange airfilter set up.  It look like they had a sealed airbox over the
>> carbs with a large diameter hose ~2" coming off the forward part of it and
>> going forward to infront of the rad. ending in a little K&N cone air filter.

John replied:
>A couple of advantages:
>1) COOL AIR. The engine is sucking cool outside air instead of the hot
>   stuff from inside the engine compartment. Denser air = more power
>2) Ram air. At speed, the forward motion of the car is pressurizing the
>   incoming air stream. No cost turbo :-)


Hi guys...

this has come up from time to time on the Z car lists as well.

The ram air effect is almost zero - some high falutin engineer type calculated
something obscene like 250 mph needed for a 1 psi boost.  Plus, even if there
was boost, it would foul up the SUs metering, since it's referenced to air
pressure.

The cool air effect is right on target, though.  However, a couple of
considerations.... the SU carb is supposedly susceptible to turbulence - so it's
important to retain some type of air-horn by the carb.  I took all this input in
stride, and promptly disregarded it, as the pretty K&N filters/housings have no
such provision.  I don't notice anything goofy from the lack of air horns, but
then again, I'm pretty goofy to begin with.

I think another benefit of the remote intake setup would be decreased noise....
SUs with open air cleaners are pretty noisy; sealing the box except for the
externally mounted filter would quiet things down a bit.

FWIW
       ____  Kyle Hagemann, Born-Again Grease Monkey From Beyond
   _.;(____\____    72 240Z, L28, 5spd, poly, etc. - The Z-Beast
  |  _ |   |  _'@`, 69 2000, U20, three speed - El Krunchariffic
  `-(#)------(#)-<  84 Maxima, 280ZX in sedan disguise - Mr. Max
http://www.sonic.net/~kyle 240Z tech info, Win95/8 theme, etc.

                "Blessed are the Car Guys."


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