This modification takes outside air from the front of the car (sort of a RAM
AIR intake) when the temperature is above 65F. When temps are below
60F (approx) the air is taken from the catalytic converter. When the
temp is in between there is a mixture of air. Some of the parts I needed
came from a 1984 Honda CRX...I still had the air cleaner assembly and
some vacuum hoses. Here is what the air cleaner assembly looks like from the 1984 Honda CRX:
Honda Automotive Parts
The parts that I used are:
1. Cut off portion of the air cleaner assembly itself
2. Air intake sensor - number 16 in the link above.
3. Vacuum check valve - purchased at Autozone (need 2 "T" as well)
4. Vacuum tubing - already had from the CRX
5. 3" to 2" PVC adapter - from Home Depot
6. 2" 90 degree elbow - from Home Depot
7. 2" extension with one side female threaded - from Home Depot
8. 1.5" Preheater hose - from JC Whitney online
9. 2" Preheater hose - from JC Whitney online
10. 2" 90 degree rubber elbow with clamp - from Home Depot
Take the 3" to 2" adapter and the inserted elbow and place it in the oven
until both are plyable. Quickly, take it out and using hand protection push
down on the end of the 3" opening to elongate it as well as the portion
were the two pieces meet. When done the 3" opening should be 1.5" x
5" (Approx - It will take a couple of heatings).
Take the air cleaner assembly and cut the air intake portion off where
it meets the circular part of the air cleaner. This portion has the vacuum
valve (missing in the link but it operates the gate.) Take the rubber
elbow and cut it to fit and glue it onto the wide side of the air intake.
The other end of the elbow will be put directly into the air cleaner on
the Insight. I did not take pictures during assembly but the air intake
with the gate will be mounted up-side-down and should look like this.
Remove the four bolts that hold the air cleaner plastic and lift the bottom
enough to route the 1.5" hose from the front to the rear by the catalytic
converter. It should look like this.
I put wrap insullation on mine and covered with duct tape. You can not
cover the whole hose with insulation until you know the final shaping.
Take the plastic cover out above the radiator on the left hand side. (I cut
a hole in mine where the molded PVC will go through). Put the PVC in
the hole with the elbow facing towards the air cleaner. Put the threaded
adapter on and the 2" preheater hose and connect the other end to the
air intake. The opening should look like this.
and the back end side
should look like this.
This is what it looks like from the top.
Take the air intake sensor and cut the glue holding the adjustment screw
in place. You want to modify it by turning the screw so the metal opens
up at about 77F (you can use the freezer for this) then glue the screw in
place again. Take the vacuum line that comes up from the intake
manifold and "T" it over to the air intake. Along the way you will need
to put a vacuum check valve in to keep the gate constant during vacuum
Drill two holes into the bottom plastic (towards the front) to accept the
sensor. The sensor must be placed inside the air cleaner because it
creates a small vacuum leak so it must have filtered air.
Connect another "T" from the check valve and put one hose on the gate
motor (really vacuum controlled gate) and the other one on the sensor.
Finally you are done. There was one day when it was 55F degrees and
the gate shut off the cold air intake and by the time I drove into work
it switched over to the RAM air intake. I put a remote thermometer in
the air cleaner to monitor the air temp but I have to wait until winter
again. I also put a screen in the RAM air intake portion just to stop
some bugs and leaves in the fall from entering the hose.
JoeCVT - Just your average CVT owner