[Tigers] Air cleaner & horsepower

[Jim]

It has been a very interesting exchange, here's hoping it continues.  See
below for some information on the relationship between air flow and
horsepower.  There are several URL's listed for additional info.  I am not
sure where the 2 to 25 hp increase citation comes from.
Jim McLaughlin
B382000175
Go to URL:
http://www.mpgenhance.com/filterhorsepower.html

Air Filter/Horsepower
          As mentioned in the air filter for fuel economy section
<http://www.mpgenhance.com/filter.html> , there is another benefit to
aftermarket air filters: horsepower increase. The concept behind how
aftermarket air filters increase horsepower and torque lies in their ability
to increase the airflow into the engine. Typically, aftermarket air filters
allow a higher cfm value or cubic feet per minute of air into the intake
plenum. Compared to stock, restrictive air filter flow, the extra air
combines with gasoline to provide the motor with more combustible fuel than
it previously had to produce energy. This results in a more energetic
explosion within the cylinder walls. As a result the pistons are forced down
with even more force, improving your vehicle's horsepower, torque, and
acceleration.
          Now, stock air filters are generally quite restrictive to air flow
as their main purpose is to prevent dust and particulates from entering the
motor. This is what they were designed to do from the factory and are very
efficient at doing so. In fact many stock replacement paper air filters
claim particulate trapping efficiencies upwards of 99.7%. While this is
great for filtering, it is very restrictive in terms of ability to flow air
into the motor.
				          This is where aftermarket filters
and performance kits (i.e. intake tubing, cold air intakes) come into play.
Typically aftermarket filters are made of a cotton gauze / screen mesh
combination. Some are oiled, others are not. The cotton gauzing is usually
more gas permeable than the paper filters. In other words they allow more
air into the engine. The oil increases the particulate trapping abilities of
the gauze in an effort to compensate for the increased flow through. In
addition many aftermarket air filters are in the shapes of cones which
increase the surface area through which air can flow into the motor. Stock
filters are flat and rectangular, limiting the amount of air that can
physically be pulled into the motor. Aftermarket filters can typically raise
horsepower by anywhere between 2 to 25 horsepower depending on the size of
the motor it is installed in. 
				           The purpose of the aftermarket
cold air tubing is to replace a vehicle's stock restrictive intake tubing
which is not optimized for performance. In fact vehicle intake tubing is
designed from the factory to help quiet the motor down in many instances via
the use of resonator tubes attached to the bottom of the intake tubing.
Aftermarket tubing, made of aluminum, stainless steel, or other materials is
usually of a larger diameter than stock to allow more air into the motor as
well. These units are also designed to keep the incoming air as cool as
possible, as colder air is denser which means more oxygen will be available
to the fuel to create more power.

				Note Tubing equals air hose, or air inlet
passageways.

[demime 1.01d removed an attachment of type application/ms-tnef which had a name of winmail.dat]