Tj Cowl Induction & Snorkle -
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Unread 08-26-2008, 09:33 AM   #1
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2001 TJ Wrangler 
Join Date: Mar 2007
Location: Atlanta-Kennesaw
Posts: 1,029
Tj Cowl Induction & Snorkle

Tj Cowl Induction & Snorkle
It's my first write-up, I will ad more pictures later.. as well as fix mistakes.
(I didn't realize I was supposed to post this in the write-ups area)

I started this project some time ago, looking at different write ups which made it a lot harder then it ended up being because you had to source junkyard parts and crap. Since sourcing the parts was a pain in the butt, I made this write-up so anyone that wanted to take a trip down to Autozone, could get everything they would need.

I have this installed and it works nice... I will add my mileage/horsepower benefits later.. as I just really did this to get clean cold air, instead of the warm dirty air it pulls from under the hood as well as a type of snorkel for deeper water driving & protection.. So far it
has provided better throttle response as well as some minuscule gas mileage increase.

DIY Stealth Snorkle/Cold Air intake:
Cost: $75

Novice install time from prep: 30-60 minutes

Requires the following:
Hole saw
And the following products:

1- Cone Air Filter – Part No. 9192 – 19.99

1- 90 degree elbow – Part No. 8698 - $9.99

2- Air Intake ducts – Part No. 8148 - $5.99

1- Air hose 3” x 3 feet – Part No. 8741 – $19.99

2- Intake Tube Coupler’s – Part No. 8771-6 – $7.99

4- 2.5” to 3” hose clamps around $4 bucks

Take the two Air intake ducts and attach them back to back using Silicone sealant so you have two ends away from each other to attach pipe to. Hold them together for a couple hours or a day to ensure a nice hold. Cut away any silicon that may appear in the center

Take off the air induction cowl which is held on by 7 screws and two wipers.
4 of the screws are along the window sill – 1 is in the center of the vent on the hood.

2 more screws are actually where the hood meets the cowl. you have to lift the hood to get to them.

The wipers have this little lip on the backside, closest to the cowl that you just pull down a half inch to let you pull off the wiper arms.

After you remove the cowl, you will see the cowl basin area, wiper motor, and AC/Heater shield duct. Depending on where you put the hole and where the air filter ends up, depends on if you will need to take out the AC/Heater shield. Keep in mind, you will need something to prevent water from flowing down the vent and onto your floor boards if you remove the little air-dam that covers this hole...

I took mine out, but I don’t think I needed to after all was said and done.. but anyway. Take it out for now. measure up and cut a whole in the firewall/cowl area so that one end of the Air Intake ducts fits through.

Drill out the firewall for the four bolt holes that you will see in the air intake ducts you attached to each other. This will allow you to mount the intake to the firewall/cowl area. I would put a little silicon where the intake duct meets the firewall) and put the bolts through and tighten it up.

Take the 90 degree elbow
and one of the Intake Tube Coupler’s

Attach one end of the rubber coupler to the air intake duct that is inside the cowl area.

Attach the other end of the rubber coupler to the 90 degree elbow (which the opening should be facing the passenger side) and then attach the Air filter
to the other end of the 90 degree elbow.

The inside is pretty much done. Depending on the clearance of the air filter, there is a small chance you may need to use a 5lb hand sledge to pound down some metal inside the cowl area. And before you close up the cowl area, turn on your wipers to make sure your motor arm will clear the 90 degree tube. Slight pipe adjustments will fix any clearance problems you will have.

Then bolt down the cowl and you are done with the first half of the project.

The second half will differ a little on how you do it…

If you have the stock ABS pipe, you can cut it down as close as you can to the throttle body, keeping in mind that you will still need petcock so the vent line can still run from the valve cover.

At this point, all you need to do is take the 3” x 3 foot Air Pipe ( and run it from the intake coupler you just attached to the firewall, to the pipe headed to the throttle body.

I have this intake riser that I think can be found on 97-98 TJ's.. and the only reason I have it was because I bought it trying to do some other custom stuff, otherwise I would have just cut off the tube running to the stock box and piped right up to it.

If you want to see what the clearance looks like from the sides:

And that is pretty much it!

The filter can be changed to whatever anyone wants.. if they have one preference over another. I just put this together to keep it simple. Sounds awesome when you press the pedal

Top down view:

You may also consider putting a cowl scoop on your rig backwards so the opening faces the windshield. You would get better airflow and keep the majority of any rain out of the cowl area all together. It has something to do with how the air hits the windshield and creates a vortex, which forces air into the cowl better then if it was facing forward.

That is what I may do next.

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Unread 09-22-2008, 05:05 PM   #2
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1998 TJ Wrangler 
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Location: O'Fallon, MO
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I had planed on this so when I seen the pic's I was off to work. My TJ looked different than his so those 2 Air intake ducts didn't work for me and I didn't use the slinky hose either. I just bought a 90%, a 45%, an intake tube reducer, and extended my PCV hose. Turned out cheaper, especially if you do the math on all those products that are listed to buy. I can supply pictures if wanted and the sound is a little bit louder when you get on it. Thats fine for me. They also say to put the cowl scoop on backwards due to the vortex by the windshield and I'm sure it helps keep water out to.
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Unread 07-29-2010, 05:58 PM   #3
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2003 TJ Wrangler 
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Location: Trinidad, Colorado
Posts: 1,229
Originally Posted by Unscathed View Post
You may also consider putting a cowl scoop on your rig backwards so the opening faces the windshield. You would get better airflow and keep the majority of any rain out of the cowl area all together. It has something to do with how the air hits the windshield and creates a vortex, which forces air into the cowl better then if it was facing forward.

That is what I may do next.
Yea, no. You want it to face forward. You're thinking more along the lines of a raised cowl hood, which is designed to draw air in through the cowl, and down around the engine for cooling, and also to reduce vacuum drag... cars with a raised cowl will still use a normal intake a top a carb or whatever they have. What you are looking at is a scoop, or a bird catcher as we liked to call them several years ago. It's more for looks than anything on a cowl of a Wrangler.
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Unread 08-01-2010, 02:01 PM   #4
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2000 TJ Wrangler 
Join Date: Mar 2009
Location: Pecan Grove, Texas
Posts: 200
Ok, I just completed this mod as well. For the people like me that love a little science to go with it, this is my findings.

I drove around for about 4 days in stock form with my scanner hooked up and recording IAT data. this is what I found.

STOCK AIRBOX-UNMODIFIED- 99 degree Houston days with 96% Humidity (gathered over 4 days)

IAT while doing 60 mph on freeway for 15 mins= 138degreesF
IAT After 10 mins Idling in traffic= 178 degreesF
Highest IAT Achevieved= 181degreesF
Coolest IAT Achieved= 111 degrees

Ok, now onto UNSCATHED's mod, which I did nearly the same but I used my stock rigid ABS intake tube.(you will notice my PCV hose is not connected yet in photos, but is now) I also installed the plastic hoodscoop over the grill.

IAT while doing 60 mph on freeway for 15 mins= 99-101 DegreesF
IAT After 10 mins Idling in traffic= 129 Degrees F
Highest IAT Achevieved= 154 Degress F
Coolest IAT Achieved=consistant 2-3 Degrees above ambient!

All in all very happy with this mod, I notice a difference in throttle response as well as a cool new growl she never had before! Enjoy the pics!
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Unread 08-08-2010, 03:52 PM   #5
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Location: Pecan Grove, Texas
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here are my results.
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Unread 08-29-2010, 11:11 AM   #6
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2000 TJ Wrangler 
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Location: Liberty Township, Ohio
Posts: 68
Spectre Performance just released their spin off this. It's nice when a company sees what the owners are doing and and puts some work into a product. Best part is the filter is removable in the engine compartment.

$159.99 from Quadratrec for the for 97-06 Jeep® Wrangler TJ & Unlimited with 4.0L Engine
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Unread 01-19-2011, 04:15 PM   #7
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2000 XJ Cherokee 
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Location: Duluth, GA
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i did this and im going to back to stock setup. the intake is so much louder than normal. annoying in my opinion.
[FONT="Franklin Gothic Medium"][SIZE="3"]98 TJ Currie arms-RC 2.5 coils-RC 2.0 shocks-1.25 BL-TF rear track bar-custom bumpstops-mud-scratches-gas.[/SIZE][/FONT]
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Unread 09-26-2011, 04:05 PM   #8
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2004 TJ Wrangler 
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I am running the Spectra and a cowl scoop/cover.
I recently did some puddle jumping during some flooding after all this damn rain we keep getting in the north east.
I pulled the filter afterwards and it was bone dry.

Puddle jumping ='s 12 to 20 inches of water and splashing it well over 20 feet in the air and all over the jeep.

Silly I know but my 7 year old Love's it!
Greg Stephens/Arboreal Specialties
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Unread 10-20-2011, 04:01 PM   #9
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Join Date: Jan 2011
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so i just installed my DIY cowl intake... it went on pretty easy... here are the parts i used:

AEM dry flow filter (same size as first post)

spectre 3 inch silicone coupler

spectre 3 inch 90* elbow

2) spectre 3 inch intake mounts

spectre 3 inch intake hose

4)1/4 20 - 1 inch- stainless bolts with washers, lock washers and nuts

4 hose clamps

I already had a rugged ridge CAI so i cut the intake just after the breather for the valve cover and since it was already 3 inches wide and had a 90* coming out of the throttle body I simply used the intake hose to make the bend to the cowl where i mounted the intake mount... used the 90* elbow on the other side and mounted the filter and put the cowl and wipers back on...


I am going to install a cowl scoop facing the windshield to minimize water... it has been raining for the last 3 days but the cowl area is still dry but this will just be a safety.

the filter needed a little bit of massage work so the cowl would fit... i used a 16 ounce rubber mallet to make room for the filter... i also had to give the filter one good bump so it did not contact the cowl... the filter fits but it is a tight squeeze.

i drilled my hole as low as I could... there is a body ground mount where i put my 3 inch hole and i simply relocated that to another bolt. I also have a 2.5 4 banger so i had to be careful with my wiring loom while i was drilling the 3 inch hole as well as the 4 1/4 holes for the bolts.

I had to trim my AC plastic shroud inside the cowl so the filter would fit... a hacksaw worked perfect on the plastic

the cowl intake is LOUD!!! actually really loud... not sure if I like this or not... I am going to drive it around for a while and see but first impressions of the noise are not good... i think it sounds "cool" but this will get old really quick... i eventually would like to do the hummer stack so maybe this will help... the filter will get its own "box" and i could always add sound deadening material in the cowl area and on the backside of the cowl as well...

other than that I will report my findings and post some pictures soon... with my new hood vents and shortened intake i think there will be less heat soak on the intake which was my main reason for moving the filter to the cowl and using the plastic flex tube... i like how this is a true CAI and wish I had done this sooner! the noise though is the only issue i have with this so far...
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Unread 07-20-2015, 08:59 AM   #10
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2002 TJ Wrangler 
Join Date: Sep 2009
Location: FT. BRAGG
Posts: 414
I know I'm bringing this back from the dead, but I just want to show offs work a little. Inside the cowl looks essentially the same as the op, but under the hood is a bit different.
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