ZJ airbox for better flow?

Well, I was at the yard today to pick up some ZJ coils and of course I got to looking around...
It looks like the ZJ air box is a good deal larger than the Xj box, even on the 4.0 ZJs. Seems to me you ought to get better flow and at the least longer filter life by switching to the larger filter box. Anyone have any insight / experience?
Woulda picked one up to find out for myself but unfortunately, ZJ drivers can't seem to keep the front end in one piece...

Cut the hole in the XJ airbox bigger. I assume the tube to the throttle body is the same diameter anyway?

You need a "redneck ramair" setup like mine. Just remove the XJ airbox and take a jigsaw and double the size of the intake hole in the front. Then cut a corresponding hole in the sheet metal behind the left headlight. I used an old license plate to "funnel" air form behind the headlight and the left edge of the radiator into the airbox. I also added a high flow filter and I get better throttle response and a few more horses for cheap! Also, pull out the restrictor in the intake tube where it connects to your airbox. Much better flow than stock. You'll also get cooler air directly into your intake which is better for performance.

:farmer:

Wouldn't the ZJ box be too big to fit in the XJ's designated area?

i love reading these questions from people who just NEED to customize something... just cause its from a differant jeep, its gotta be good?

if you want to customize your ride, do it, dont ask how
.....THEN post here, about how it went...

Right... Helpful. I'm glad you had your 2 cents in.
My reasoning was that a larger filter element would allow more flow and last longer for a given CFM being drawn through it. There are a whole lot of folk doing the same with after-market oiled filters that are not as good for dirt use. I thought this would be a suitable replacement.
If the junkyard had had the parts, you'd have read a writeup.
In the meantime, I thought I'd ask if anyone had relevant experience.
I'm so glad you chose to post a reply.

But still isn't the tube leading to the airbox the same diameter?

So airflow really can't increase? Whatever it's being sucked in at from the intake is all it will do, I think. Even if the airbox is bigger.

90PioSport99 said:

Wouldn't the ZJ box be too big to fit in the XJ's designated area?

Click to expand...

Thats my one thought as well. The stock airbox barely has enough room as it is. Anything bigger wouldnt fit.

Blaine B. said:

Cut the hole in the XJ airbox bigger. I assume the tube to the throttle body is the same diameter anyway?

Click to expand...

I did this, and didn't really notice any increased performance/ecnonomy gain. I did notice, that it made it much easier for water to get in there if you're out playing in water crossings/flooded streets. I find it far too easy to get water in there anyways, so I picked up another stock airbox that hadn't been hacked and put it in.

If somebody else wants to give it a shot and doesn't want to hack up their airbox incase they want to use it again, I still have the one I cut up for sale.

and last longer for a given CFM being drawn through it
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If you live/off in a very dusty region yes. Else the stock filter is more then is needed for most offing. I ran 1/8 and 1/4 mile test with no air filter and it didn't help. Maybe if you rev over 5K or are going more then 80 MPH it might help.
Some XJ have a silencer in the line to the TB. Some remove this to.