CAI for SpecV

Maurice Hilarius maurice@harddata.com
Sun, 15 Sep 2002 02:58:09 -0500


I looked at the various cold air intakes being offered by Hotshot, Stillen,
etc., and realized that while they work, I did not really like them.
What I don't like:
They are not insulated. So as the engine compartment gets hot, so does the
intake tube.
They cost too much. $200 for an aluminum tube and some clamps and a rubber
hose?
The don't look like they flow much. A JWT POPcharger flows LOTS of air.
Huge surface area, no tubes, etc. However the POPcharger came with a really
flimsy bracket to hold it, and did not fit well. It bounced around a lot,
rubbing at the liner under the hood, and generally was hard to install and
service.
  BUT, some have said I would be sucking in hot air from the engine
compartment. Frankly I think that is mostly hogwash. Sure, lots of guys
have done dyno runs, and as the engine heats up the horsepower goes down.
Of course the car is standing still so almost no fresh air is flowing into
the engine compartment!

Still, I looked at my engine compartment, and noticed some things:
1) there is a lot of cold air flowing in from the front grille, and a big
hole into the left wheel well.
2) All I would have to do is exclude the hot air from the engine area.
3) A JWT POPcharger needs a solid and serviceable mount.

So, I removed all the bracketing in that area, relocated things like the
wiring harness, wiring connector brackets, and revised the battery clamps a
small amount to make room, cleaned up the incredibly cheap and lousy way
that Nissan protected and routed the wiring harness in that area, and made
an air box, that gets cold air from the front, next to the battery box.
I made it from plastic corrugated sheet, commonly called "coralite" This is
like 1/4" cardboard in structure, but made of ethylene plastic. As it is
double wall plastic sheet with air-filled pockets it is a really good
insulator. It's strong, flexible, and easy to work with. And it is cheap!
I covered the engine side of it with self-adhesive insulation foam that is
covered with an aluminum foil skin. This is reflective and a very effective
insulator. This stuff comes in rolls and is meant to insulate hot air pipes
in a home heating system. It is backed with self adhesive foam, and cuts
with scissors.
I made an air intake cutout and holes to mount the POPcharger in the box.
I secured the airbox to the wheel well and fender area using existing bolt
holes liberated by moving the wiring harness connector block bracket
slightly back, secured to 2 new holes I drilled in the strut tower part of
the wheel well. The clips on the block assembly pop into these holes, where
before they popped into this extra useless bracket that gets in the way.

Testing:
Once I had it built and installed I took it for a good half hour hard run
to heat things up.
I put the sensor probe of an electronic temperature meter in the airbox cavity.
With outdoor air temperature of 24C ( 76F) and running in 2nd gear at 4,100
rpm for 10 minutes, the air temperature at the air intake filter stabilized
at 27C (80F).
I get lots of airflow, as good as just the POPcharger mounted wide open.
I can get at the air filter for servicing without fighting to get around
anything.
The intake runner from the air filter is now straightened out considerably,
so it is at half the angle it was with the stock airbox. There is only one
very slight bend in the air tube to the injector body.
The top of the airbox fits snugly to the underside of the hood, also
keeping the warm air out, and reducing noise.
The sound from the intake is now almost as quiet as the stock air box.
Unlike most CAI setups, it takes second to remove the air filter, and is
totally accessible.

If anyone wants to see pictures of the install, from start to finish look
at this web shots page:
http://community.webshots.com/album/50112924nxFPul

While I was at it I remove the original brackets and bolts holding the
battery down, and replaced it with a nylon cinch strap (doubled up) and a
metal cinch buckle. Now I have a nice solid battery, yet can remove it with
2 fingers on the buckle release.

All the parts used were picked up at my local Home Depot store, and cost me
about $30 Canadian.
If anyone wants I can send them a parts list, and a scaled drawing template
to cut the air box from. It was a lot of work to figure it all out, and
about 4 tries at templates to get it right, but with the template and
normal tools one could make it and install in about 2 hours of work.

With our best regards,

Maurice W. Hilarius       Telephone: 01-780-456-9771
Hard Data Ltd.               FAX:       01-780-456-9772
11060 - 166 Avenue        mailto:maurice@harddata.com
Edmonton, AB, Canada      http://www.harddata.com/
    T5X 1Y3

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