Cowl Air
Intake
3/28/09
For several years I have had an ARB Safari
snorkel as my intake. It just so happens that the cage I am getting
ready to build is going to have a tube running up the outside of the
A-pillar, right where the snorkel is. So as much as I like having
the snorkel, it has to go. That left me with a new problem - what to
do for an intake? I didn't want to go back to any intake (stock or
cone filter) that gives up the ability to cross deep water. After
looking at what several other people did, and concluding that no
matter how I tried I would not be able to keep the filter dry if it
was inside the engine bay, I decided to relocate the filter to
inside the cowl.
The "cowl" is the hollow area between the dash and
the engine compartment. Inside the driver-side section of the cowl
is where the windshield wiper motor is. The passenger-side section
of the cowl is mostly vacant and that is where the HVAC system draws
air from. As seen in the photo below with the cowl grill removed,
the driver-side is open (for air to enter) but the passenger side is
not open on the top (to prevent water from entering right over the
HVAC duct). |
| The passenger-side cowl is an ideal spot
for the filter, however to get it in there we need to cut a hole in
the top. |
Even though a hole was cut in the top, not
much water will enter here because the cowl grill does not have any
vent holes on that side. You can see the underside of the cowl grill
in the photo above. Mine is a 2000 and older models may have vent
holes here (I'm not 100% positive). But if that is true in your case
you could find a way to seal them off, leaving only vent holes on
the driver-side.
Now before going any further, let me give you a parts list of
what I used. You may be able to find this stuff cheaper, but I chose
the convenient route and bought the main parts at Summit Racing
since their warehouse is close by. |
| item |
part # |
cost |
| Airaid cone filter |
Summit AID-700-430 |
$31.95 |
| 3.0" OD exhaust pipe |
Summit SUM-640030 |
$12.95 |
| 3.0" ID connector |
Summit WLK-41892 |
$15.95 |
| 3.0" x 30" Spectre
flex tube |
Summit SPE-8741 |
$25.99 |
| 3.0" black ABS pipe |
Home Depot |
$5 |
| misc hose fittings and clamps |
Home Depot |
~ $10 |
I also found this write-up
http://www.cardomain.com/ride/325707/7
(thanks Balloo93) which gave me the idea to use the 3.0"
exhaust pipe. I found a slip-fit pipe like his but it was only 10"
long. I needed about 2 feet which is why I ordered the pipe from
Summit. In hindsight I could have saved a lot of money by ordering
the 10" slip fit piece and using the full length of the 30"
flex tubing, but oh well.
Here is the Airaid cone filter. I chose this filter because of
its dimensions. It has a 3 1/2" flange, 4 5/8" base, 3 1/2"
top, and is 7" long. It fits just inside the cowl, but it isn't
too small of a filter either. I mounted it to a short section of 3.0"
(ID) black ABS pipe because this pipe has an outside diameter of 3
1/2". Then added a short section of exhaust pipe for the flex
hose to mount to. |
| Here it is tucked into the cowl. |
| Here is the flex hose coming through into
the engine bay. I used a 3" hole saw for the opening and had to
open the hole up a bit more to fit the flex hose through. Also to
make room for the tube I had to relocate the under-hood light,
relocate the EVAP purge solenoid, and move the large loom of wires
out of the way. It was not hard. |
| And here is the rest of it going to the
throttle body. As indicated by Balloo's write-up, the diameter of
the exhaust coupler I used is exactly what you need to attach the
stock "accordian" throttle body tube. I welded the coupler
in place but it was such a tight fit I think it would have been just
fine without welding it. I also plumbed the CCV tube like in
Balloo's write-up. |
Impressions
| I was told by a friend who also had his
intake set up this way that it might be loud inside the cab. He was
right! When I first started the engine I was shocked at how loud the
sucking sound was coming through the vents. After a few seconds the
sound diminishes to where you can barely hear it, but I was still
concerned that the sound might be an annoyance. Well after driving
on the highway and on a trail ride, I had completely forgotten about
the sound and didn't notice it at all. For the person who is overly
concerned with noise in the cab, this modification might not be
right for you. As far as any "performance" gain, I didn't
notice any increase or decrease, but I wasn't expecting any either.
As side benefits to this modification, I am still sucking cold air
and I can get rid of the stock airbox, creating more room in the
engine bay. Overall I am very happy with this modification. |
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