Mustangs like cool air, and the reason is that cold air is denser and
has more O2 in it, which in increases combustion efficiency.
When you install a K&N conical filter inside the engine bay 2 things
happen; the engine heats the inside air and the fan creates turbulence,
both of which hurt performance.
There are several ways to eliminate those problems, one could be to install
a RAM AIR hood which has openings at the front to draw cold air into the
engine, or at the back to expel the heated air. But hoods are expensive
and we think there's a better solution for the budget enthusiast.
Our 1995 5.0 project car was fitted with a 9 inch conical K&N without
the air filter housing, but the filter sat inside the engine compartment
and inhaled mostly hot air and that hurt performance.
We decided to make a SN95 5.0 COLD AIR INDUCTION kit(CAI) setup that
would relocate the filter to the fenderwell to draw cooler exterior air.
There are many CAI kits available from MAC, BBK and others, but we think
the price you pay for them is a bit on the high side.
Some changes need to be done to create a CAI for other Mustang
models, but the same principles apply.
Our first attempts
at making a home CAI consisted on using PVC pipes and elbows, but
the PVC wont last long inside the engine bay, the heat will just deteriorate
the PVC until it collapses due to the heat and the suction created by
the intake, so this new CAI version uses not only different materials,
but also a different configuration.
We decided to use 3" STEEL pipe instead of PVC, but the elbow is
still a high quality PVC piece.
change from our previous setup is the the removal of the MAF adapter (only
needed for SN95s) which hooked the square side of the maf to the K&N.
(see picture on the left).
You will also need a K&N Conical filter for this setup, you can use
the STOCK K&N replacement air filter, or any conical filter that doesnt
have an elbow (flat).
We went to a muffler shop and bought a 3 inch Steel pipe (Can also use
aluminum), 1 45° angled PVC elbow, two 3 inch rubber hoses and 4 high
quality stainless hose clamps.
If you have a stock Air box in there, the first step is to remove it.
Loosen all clamps and hoses, remove the IAT (temp sensor) and PCV hose
from the passenger side valvecover, remove the MAF wiring harness, pull
the air box, open it and remove the MAF. When everything was removed we
decided to clean all the space beneath since it was VERY dirty.
all the cleaning was done, we started measuring the TB to fender well
opening distance to cut our PVC pipe.
The Steel pipe should measure around 20 inches, plus the 45° elbow. Test
try the pipe before you join the parts.
2 holes on the pipe, one for the crankcase ventilation and the
other for the Air Charge Temperature
To connect the Crankcase ventilation we used a copper hose connector and
a 1" clamp we found at the plumbing section @ Home Depot. The ACT
sensor is installed in the second hole, make the hole big enough for the
sensor to screw into the pipe, enlarge it a bit at a time so the sensor
is held tightly in place. You can also use a rubber grommet into which
the intake sensor will screw.
Next you need to screw the square side of the MAF to the K&N filter,
use some silicone sealant and dont forget to place the wire mesh between
the MAF and filter, the mesh straightend the air flow inside the MAF.
Use quality nikel plated or stainless screws.
The next diagram shows the complete assembly: FILTER + MAF + HOSE + ELBOW
+ PIPE + HOSE + TB:
The PVC elbow and Pipe can be glued with Epoxy, for extra safety you
can put some reinforcing screws. Do this before you paint it.
is PAINT PREP TIME, we used 600 grit sandpaper to sand all pieces and
then cleaned the outside and inside of the pipe with a lint free
cloth. You dont want any contaminants to get into the intake and engine,
so you better clean it right !!!.
used KRYLON high temperature paint to give the whole setup a nice factory
look. Wait at least 2 hours before installing, high temperature paints
dont dry as quick as regular paints.
When the CAI is dry it's time to install it, assemble the K&N + MAF
+ HOSE and get it inside the fenderwell, theres enough room under the
car to put it in place. Now connect the MAF wiring harness to it, the
wiring is long enough so you dont need to do any modifications to it.
the other rubber hose at the throttle body, attach the CAI pipe first
to the MAF, its a bit tight inside the fenderwell but be patient, a short
screwdriver or small wrench can be used to tighten the hose clamps. Then
attach the pipe to the TB. By now the job is almost finished, just a few
things left to do like attaching the ACT sensor and CV hose.
We will suggest you erase the EEC stored memory tables, do this by disconnecting
the battery for 20 minutes.
Now start the engine, and check for any possible problems, like air leaks
or the hated "Check Engine" light.
Our overall impression of this setup is that it surely provides some
more HP, but it is felt mostly at mid-to-upper RPM's.
Most aftermarket CAI's are said to give you 10 to 15 hp increase, but
if you look at their design it has several flaws, they still have some
90° bends that will disrupt airflow. Our design is superior as it
only has 1 45° bend and it is right after the MAF so the airflow is
more even and wont harm MAF readings.