enclosed K&N, gain of 3 HP

[Maurice Hilarius]

One day at band camp, George Roffe said:

>Guys, the colder air accounts for an almost immeasurable amount of hp.  I
>personally know of instrumented testing on a B14 SE-R, a P11 Primera, and a
>Porsche 944.  In all cases the under-hood temps with the car moving were
>within just a few degrees of ambient.
Exactly. And if the CAI adds too much intake resistance it will likely
reduce flow and power.

>A CAI makes power mainly through resonance tuning.  A wavefront reflects at
>the ends of open tubes.  Those wavefronts help speed along the incoming air in
>a CAI.  This makes the intake, and thus the engine, more efficient, allowing
>it to make more power.
"Intake manifold runner extensions" is what it becomes under these
circumstances.
I would guess that short of doing extensive testing on a dyno, and at
different conditions of temperature, humidity, etc., there is no reliable
way of determining at exactly what length and diameter it will either help
or hinder performance. As those who are selling CAIs right now do not seem
willing to provide ANY dyno charts, I suspect that these are purely " make
them fit and hope it works" jobs..

>You need to be careful what some monkeys post to the web.  First of all I
>don't generally trust individual's dyno tests.  There are many folks here I
>trust, but mainly that's because they have learned from Mike Kojima how to
>conduct dyno tests (stabilze temps and other things before starting a run).
>It's really easy to get pretty wide variations from pull to pull.  Some monkey
>who doesn't know what they are doing could get all sorts of misleading
>results.

Especially with air temperature variation..

With our best regards,

Maurice W. Hilarius       Telephone: 01-780-456-9771
Hard Data Ltd.               FAX:       01-780-456-9772
11060 - 166 Avenue        mailto:maurice@harddata.com
Edmonton, AB, Canada      http://www.harddata.com/
    T5X 1Y3

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