Cherokee XJ Cowl/Hummer Snorkel Build / How - To

There are several ways to go about installing a snorkel on an XJ. All of them require drilling, and some are more expensive then others. The most effecient way to go about doing it is to pick up an ARB Safari style snorkel that runs up along the A-post. I thought long and hard about that one, but a hole in the fender and $450 put it out of the question. Below is my version of the cowl/hummer style snorkel, a much more inexpensive yet efficient and fully functional way of doing it.

There is a how-to on Eric's XJ (Eric's XJ) on a cowl snorkle that ends at the cowl on the engine side. This was my original intention, but found that after about a minute of "rainfall" that passenger side area was moist. This is what prompted me to go for the hummer style look. Here is a picture of that:




I used several previous how-to's prior to tackling this project:
1. http://www.jeepforum.com/forum/f27/write-up-hummer-cold-air-intake-326040/
2. http://www.jeepforum.com/forum/f9/hummer-snorkel-complete-279468/
3. http://www.jeepforum.com/forum/f11/project-relapse-build-thread-804449/

Supplies:
1x Flexible 2" coupling
1x 90 degree or 45 degree 2" flexible connector
1x 3" to 2" reducer
1x 8 inches of 2" PVC (They usually come in sections of 2 feet)
1x 2" flexible hose (I opted for shopvac hose, sold in 2.25" - It is actually 2")
1x Roll of aluminum tape
1x tube of silicone (I opted for Black high temp RTV, as i had two tubes sitting in my garage)
1x PVC Cap (The one shown in this build is easiest, otherwise use L brackets as shown in link #3 above)


(Ignore the plastic coupling in the picture above, you will not use it)

Tools:
Drill with 2" Hole saw
Dremel


How to: (Before drilling into your car and playing with the intake system, take a deep breath and understand that i'm not responsible for you messing your car up.)

1. Remove the wipers (Pop up the clips on the back and wiggle them off) and undo the screws on the cowl area cover.
The area should now look like this:


2. Mark where you want the tube to enter the cowl with a pen at the center. Use a smaller drill bit to go through it.


3. Using the 2" hole saw on your drill, drill your 2" hole. After you have drilled, be sure to spray the edges with spray paint. You do not what the edges to rust.

http://i277.photobucket.com/albums/kk51/raphic/IMGP4498.jpg

4. Moving to the top, decide where you want the intake to sit. reinstall the cowl cover (the piece with the vents). Mark the center of where you want it to sit. Drill through the cover and the metal sheet beneath is with a small drill bit.

5. Remove the cover. Using your 2" hole saw drill through the cover and the metal. I would suggest doing the two seperately.




6. Join the reducer coupler and the cap using the two supplied screws. I would suggest painting them now.



7. Cut the connecter off of your tube if you used the shopvac tubing.

8. Using your 2" flexible coupler, spread silicon on the inside edges as below. Do the same on the outside of the flex tubing.




9. Feed the attached tube and coupling through the hole on the engine side and pull it up towards the sky into the hole on the top. You may need to extend the edges on the first hole to feed the coupler through all the way (using the dremel).



10. As you did before, spread silicone on the inside of the coupler. Attach the cover with the reduced and a small section (about 4") of your 2" pvc piping.

11. Remove your airbox. Using a piece of sheet metal or plastic, cover the old intake and seal it with silicone. Drill a new 2" hole on the opposite end with your hole saw.

12. Feed your 90/45 degree coupling through the new hole in the airbox and seal it with silicone.



13. Wrap your flex tubing with the aluminum tape. If you prefer, paint it black as I did.

14. Spread silicon on the opposite end of the connector and on the hose as you did with the 2" coupling on the other end. Attach the two pieces. Using silicon, fill the drainage holes in your airbox.

15. You're done! Let it all dry, you should now be in service.





:smootch:

Neat, but why did you want to keep the stock airbox?

Dest said:

Neat, but why did you want to keep the stock airbox?

Click to expand...

I would guess for the actual filter.

one question;

any thoughts on the 2" pipe being restrictive to the intake?
I could see it closer to the TB, as it might speed up the air a bit, but going from 2" ridged/flexy pipe to open box/filter, then into larger 3" pipe to TB... just seems like it would restrict your air getting into the engine.

beakie said:

I would guess for the actual filter.

one question;

any thoughts on the 2" pipe being restrictive to the intake?
I could see it closer to the TB, as it might speed up the air a bit, but going from 2" ridged/flexy pipe to open box/filter, then into larger 3" pipe to TB... just seems like it would restrict your air getting into the engine.

Click to expand...

There's been some talk of this elsewhere as well. I contacted two other people who had used this method, both of whom used the 2" tubing. Both reported no loss of power, thus leaving me with no objection to using the 2" tubing. The 3" transformer there isn't a large piece, I just felt that It would look better with a larger downtube from the cap.

So far, after a few test drives, I haven't found anything that would suggest a lack of air to the engine.

We'll see how it holds up on the trail this weekend.

Did you seal off the airboxes original intake port?

nice right up, good to have many options when building a snorkel. I made mine out of 2 inch PVC and used an aluminum roof vent cap to top it off. Painted it tan, and I think it looks clean. oh and its a "standard" style snorkel, my fenders were already pretty dented.

The location looks a little awkward IMHO, and the hose looks kinda ugly being all crinkly. looks thrown in. And the propose of aftermarket intakes are to create a more direct, smooth flow of air, the plastic tube makes the air kinda bounce around, creating resistance. Im not saying its not functional for your purpose, just trying to say that many high performance intakes are made of mandrel bent tubes for a reason, no reason to make flow worse then stock. But really isnt an issue if your not having a noticeable lag in power.

If I were you, i would run a solid tube along the fire wall and figure out how to plum it together. would look cleaner and provide smoother airflow. Also, for some reason I get the feeling that wrapping a tube in aluminum and painting it black would absorb heat, but really have no idea. Is this a good way to insulate stuff under the hood?

But again, great right up. never seen the process of how hummer style intakes were done.

How water tight is the stock airbox?

i did a something close to that but put the intake tube in the wiper motor compartment, routed it just above the master cylinder and. less piping, less restriction, no visual eye sore, and utilizes the stock air filter. air sucks in through the vent slots next to the drivers wiper...

oh forgot to ad that as long as you seal the stock box with a bit of silicon, its works good as an extra line of defense to water getting sucked into the intake. I doubt any water would jump up through the filter. Just talking slight leak here.

Nice job!
I just dig my hood pins and need a new project... This might be next. Bookmarked!

Nice job!
I just dig my hood pins and need a new project... This might be next. Bookmarked!

With 2" tubing it's like breathing through a straw. It'd be neat to see some before and after dyno results.

You should have used this!

I'm with the rest on the 2" tubing but if it works, not gonna argue with it. Looks fairly well sealed. I've seen one done where a solid tube was used that went straight across the valve cover I think, but I don't know where the writeup went.

Just a minor nitpick... silicon and silicone are two different things :spin1: a pet peeve of mine. Silicon is a hard grey semimetallic element, silicone is that rubber they make fake boobs out of. The two are very different :shocked: though silicone actually contains silicon.

Its different, which isn't necessarily bad but I agree you should use some bigger piping on it.

2" is just too small, no doubt its going to hurt your power, but also its just to be stucking air in so hard that if water does come up to that general area, there is a good chance its gonna stuck it right up.


EDIT: Also just watch that hose you used the first couple times out, i have seen them melt small holes if they touch the wrong area.

Is there a reason why you could not put the air admission on the driver side ? Wipper motor maybe ?

Correct, the wiper motor is located on the driver side.

Hey All,

It's been a full day since it's all gone on.

So far:

No lack of power.
There is no serious "sucking" at the top of the intake.
No holes in the tubing.

I will look into going to 3" hose, but considering I haven't run into any problems as of yet, i might just stay with this.

Cheers!
:clap:

lets see it in action