Basic (FREE) Air Intake Modifications
(1999+ model years
with straight throttle body)
Ok, out of the factory the stock air box
is rather restrictive to say the least.
It has a small intake port, a cheap paper filter and an air silencing baffle
that all work together to create a quiet and less effective air intake system
than it could be. There are a few
simple and some free things that you can do to change this. Some of the mods on this page will need to
be done anyway if you plan on getting an aftermarket cold air induction such as
the SLP Ram Air or Fast Toys Ram Air kit.
Lets get started.
First: Plan on
trashing that stock paper filter. Get a
K&N or other aftermarket hi flow reusable filter.
Second: To
increase the intake port size on the air box remove the air box from the
car. See how the bottom of the air box
is blocked? You can cut that out
leaving about a quarter inch all the way around. Leave the center section, however, as this gives rigidity to the
air box frame. You now have a much
larger air intake port. (You will be
doing this anyway if you get a ram air kit)
Most of this airflow will be from in front of the radiator so you
probably don’t need to worry about air temps even if you do not have a ram air kit
yet.
You can also trim away some of the upper
light plastic radiator shroud as well to improve airflow to the bottom of the
air box. Suggest putting some cardboard
in front of the radiator for protection.
Medium sized tin snips work great for trimming the shroud. To remove the shroud there are push pins on
either side you can get to from under the car as well as two ‘turn to fit’
style push pins in the middle lower portion of shroud. You can almost see them in the above
picture.
Third: See all
those fins on the underside of the air box lid? Those are causing turbulence in the air intake system and also
acting as sound baffles. If you remove
them airflow will be enhanced. WEAR SAFETY GOGGLES. I used some normal old wire cutters and just kept clipping and
trimming down the fins. The pieces of
plastic really fly up and around as they are clipped so WEAR SAFETY GOGGLES. (Click HERE to see what happens when you do not take proper
safety precautions) Be careful not to
try and take too much material away at one time or you could possibly break
through the lid. Just start small and
work your way down until there is very little fin left. Next you can sand with 40-80 grit paper
until the underside is smooth. The
smoother the lid the better the airflow will be. Now wash the lid in warm soap and water several times. Double check that all dust and loose chips
are gone and then wash the lid again before reinstalling it.
Air
box lid with fins Air box lid with fins
removed and surface sanded smooth (well, pretty smooth)
Fourth: After you
have done all that of course you want to get rid of that air baffle. You can buy (50 bucks) a smooth air bellows
or you can make one out of some PVC pipe and coupler. To make a PVC bellows I used a female-to-female 3” coupler and
about a 4” section of 3” PVC pipe. (The black kind) The female-female coupler will almost work. It alone was not quite long enough to make
the connection between the air box rubber coupler and the TB rubber coupler in
my opinion. (Especially considering
that you need a little play as the engine torques and rocks back and
forth) The female-to-female 3” black
PVC coupler has the perfect outside diameter to mate with the air box rubber
coupler. Get appropriate band clamps
while you are at the hardware store to replace the crimp style stock
clamps. The 3” diameter PVC pipe is
perfect size to the mate with the TB rubber coupler. Get these two pieces sized and cut, sand edges of cut surfaces
and clean well in warm soap and water.
You can use PVC glue or even a thin layer of RTV BLUE silicon gasket
sealer to make the connection solid and air tight between the PVC pipe and the
PVC coupler. Tighten down all the
clamps and you now have a very affordable smooth air bellows.
Stock Air Silencer PVC Smooth
Bellows PVC Smooth Bellows
Aftermarket Cold Air Induction Kits
Fast
Toys Ram Air Induction Kit (FTRAIK)
“The Fast Toys ram air system
(FTRA) is designed to force cold, high pressure air into your engine to build
more horsepower. The system brings in cold fresh air which contains more oxygen
than the warmer air the car normally breathes. In addition, this system will
achieve a mild pressurizing of the sealed air box at higher speeds and improve
volumetric engine efficiency for more power! Your car will also benefit from
improved throttle response on the roll, better highway passing power and
increased top end pulling power.”
The above
sales literature is true. Whether or
not the system develops ‘positive pressurization’ you will notice better
throttle response and more power through entire rpm range, etc. The price for the FTRAIK is about $175 or so
with shipping. It can be installed in
about an hour. It comes with detailed
and easy to follow instructions.
The below pics
show the FTRAIK installed as seen with air box lid off and filter removed. The second pic shows the rest of the
kit…namely the ‘ram air’ portion that when installed contiues all the way down
to the lower air deflector. You also
get a block off plate for use in very wet conditions such as deep puddles,
etc. (Here in Seattle I have yet to use
the block off plate. Awfull wet at
times, too. )
SLP Cold Air Induction. For the straight throttle body v-6 cars this is very similar to the FTRAIK. It costs less than than the Fast Toys version but does not come with the Ram Air kit. The basic SLP Cold Air Induction Kit costs about $120. You can buy the ram air upgrade kit seperatly for about $50.
Both off these kits use stainless steel and come with everything you need to seal up the airbox, fasteners, etc.
High
Flow Air Box Assembly
“Bolt on
some easy rear wheel HP for your 98-02 Fbody! This brand new high flow air box
assembly is a complete replacement for the restrictive stock air box. Features
include: larger frontal opening, and fully open base. This is complete assembly
which included a new radiator shroud! This package includes a K&N Corvette
air filter which is significantly larger than the stock air filter for maxium
air flow. The airbox is constructed of high quality injection molded plastic
for maxium strength and durability. Bolts on in 10 minutes with no
modifications required to any oem components. Stainless steel mounting hardware
included. V6 models also available!”
|
STLBOX3 |
High Flow Air Box For 98-02 V6 |
375.99 |
http://www.fasttoys.net/
