Stock air box.

[Greaser]

quote:

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Originally posted by jeepzj:
I have a 1998 Jeep Grand Cherokee 4.0L. Any harm removing the neck from the stock airbox that goes to the grill? It looks like it's purpose is to suck in cooler air from the grill but it's construction looks to be restricting air flow. If I remove it I will be left with a pretty nice large round opening right on the front of the airbox to suck in more air although probably warmer air. What about water?

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I would leave it on...colder air is what you want...even though it looks restrictive usually the inside of the air box is designed to use the restiction to draw air in quicker...like a velocity stack...my TJ has the same type of set-up...a small diameter air horn going to a large air box...works just fine...most test performed with K&N air tubes showed a LOSS of horsepower with the stock airbox removed...leave it alone IMO.

 

[Chris142]

I agree. Leave it in.

I removed the horn lookin thing from my 02'Wrangler once because it looked restrictive.

The intake noise was louder, power was down and the check engine light came on after a few minutes.

 

[jeepzj]

I have a 1998 Jeep Grand Cherokee 4.0L. Any harm removing the neck from the stock airbox that goes to the grill? It looks like it's purpose is to suck in cooler air from the grill but it's construction looks to be restricting air flow. If I remove it I will be left with a pretty nice large round opening right on the front of the airbox to suck in more air although probably warmer air. What about water?

[ July 13, 2003, 12:49 PM: Message edited by: jeepzj ]

 

[crossbow]

Search for a forum on your specific vehicle.

Many times a stock airbox can be "modified" to both prevent CEL (Check engine lights) and to increase airflow while decreasing air temp.

Combine with a higher quality (then stock) airfilter...and you can add anywhere from 1 to 12 WHP. (All dependent on how restrictive your stock intake is).

Usually the MAF/vacum sensors throw the CEL's.

 

[Drew99GT]

If your airbox still has a resonate tuning chamber/resonator on the tube after the airbox, then you can usually gain some performance from removing restricions entering the airbox, but don't make it too big an opening or you will kill air velocity. If you car doesn't have a resonant tuning chamber, which aids in volumetirc efficiency, you'll lose power by opening up the airbox or removing the tubing that enters the airbox etc. I'd just leave it stock.

[ July 16, 2003, 09:30 PM: Message edited by: Drew99GT ]

 

[jeepzj]

I think I'll leave it alone. Thanks.

 

[darrenc]

The ZJ 4.0 is not starved for air. 5.2...well, that's a different story. The 4.0s air box is not a bottleneck, and there are no performace gains to be gotten from its modification or through use of a high performance filter like the K&N's FIPK. The bottleneck on this motor is the oldfashoned two-valve push-rod head with intake and exhaust on same side. I doubt that cold air would do anything with this head design either.

But, the 242 is tractor tough (even sounds like one). My 96 ZJ has 122000 miles on the clock, and it still runs like brand new.