the effects of Ram Air
you remember one thing from high school chemistry class, it might
just be that gasses, such as air, become denser when cooled. When
it comes to engines, cold air means more molecules of oxygen available
for combustion. This boils down to more power.
Supplying an engine with fresh cold air is a benefit most auto makers
have exploited since the '60s. Unfortunately the better air quality
usually comes at the expense of air quantity, as the factory
air cleaners are restrictive and designed to minimize sound rather
than maximize flow. Most of us try to solve the quantity problem
by installing the "muscle car" standard, a 14-inch open
element air cleaner. Though it does breath well, it sucks in hot
air from the engine compartment.
The ideal situation is a ram-air setup, which not only provides
the engine with cold air, but also large quantities of pressurized
air. Air pressure at the front of a car can be as high as 3"
of Hg at 80 mph. Directing this to the carb is essentially a free,
albeit very small, supercharger!
Until recently making an effective ram air induction for your carbed
engine meant either installing a big and conspicuous scoop on the
hood, or fabricating an sealed air-cleaner and running ducts to
the front of the car. In other words, it wasn't a simple task, and
the end result often didn't look too great.
Fortunately a company called Air Inlet Systems has made installing
a ram air system on your carbed Ford a very simple project. AIS
makes the "Ram Air Box" a high-capacity, air filter housing
with twin snorkels. The hand-laid fiberglass housing has been designed
to optimize air flow and pressurization. Flow comparisons between
the stock 1985 Mustang HO dual-snorkel (14"x3") air-cleaner
and an AIS 14"x3"with 80 deg. snorkers, show an increase
of over 350 cfm (Superflow 1020 pro-bench with pressure set at 10
inches of water.)
The beauty of the Ram Air Box, besides its exceptional flow, is
that is utilizes a standard 14" diameter base, lid, and air
filter. Depending on hood and engine accesory clearance the box
itself can be ordered in a 3", 4", or 5" tall configurations,
with either 80 or 110 degree separations between the snorkels.
AIS claims most users see a 2 to 4 tenths improvement in ET, and
as much as 10% increase in power and long range fuel economy.
We decided to see if we could confirm these claims for ourselves.
Our 1967 Mustang had been running consistent 13.0 - 13.10 for the
past five months, with seemingly no hope for a 12 second time slip.
No matter what we tried we could not gain that extra tenth. So needless
to say, we weren't too convinced that the Ram Air Box would do it.
Fortunately we were proved wrong! Very wrong! Quarter mile results
confirmed over 2 tenths improvement and a gain of 3 mph over our
previous bests without ram-air. To top it off, we noticed an increase
of about 2 mpg on our 100 mile roundtrip drive to and from the racetrack.
track tested the Ram Air Box on Project '67. We
made no changes to the engine or car other than
installing the Ram Air Box. The 289 powered Mustang
had run a previous best of 13.03 @ 104. Just to
show its no fluke, we made six passes on the same
day with the Ram Air Box, and all six were in
the 12's! The top three are listed here:
w/ air filter
w/o air filter
Ram Air Box
(Previous Best ET)
is absolutely no doubt that the design of the Ram Air Box yields
convincing results. This may in fact be the cheapest horsepower
you can buy for your carbed Ford! We were also curious if the
Ram Air Box worked better without an air filter, but we actually
lost a tenth and 1 mph without it. We figure the air filter reduces
turbulence in the box and straightens the air flow to the carb.
As mentioned before, we used a cheap paper filter, but a good
cotton gauze will flow better. Who knows, we may still be able
to squeeze another tenth out of the 289! F/M
AIR INLET SYSTEMS
177 Grace Avenue
Phone (905) 549-6135