VBS4

Well I found a local guy that gave me his stock airbox
So I'm doing some experimenting with it.

So far I popped out the snorkle and used a dremel to enlarge the entire snorkle hole. It's probably twice the size of the original hole was. I also tossed in a K&N panel filter and reset the computer. We'll see what happens when the computer adjusts to it.

While looking at the accordian hose that runs from the airbox to the TB, I noticed the hose starts off at 3" but abruptly (no sloped transition) drops to under 2.5", then enlarges again after about 7 in's. So my next step will be to replace the accordian hose with a 3" piece all the way to the TB. We'll see what happens.

I'd love to have a scan tool that can monitor the engine's sensors. We could easily see if there's an increase in airflow.

So far:
Cost is only $50 for the drop in filter.
It definitely has a deeper growl under full throttle.
Seems to have more pep to it.

D'sjk

I was going to buy a K&N air intake but I think the spending $30 for the K&N filter the trying the holes drilled it might save me $240 that I can speand on the other mods I have planned!

cjsdad

I know some have said that there is no hp gain. I just drilled my holes and went for a quick drive. Idleing, there is no diff in noise. When riding, top and windows down, there was DEFINETLEY a notice that it had a little growl to it and there was a little more pick up. I didn't hit the interstate, but just around the block, I noticed taht my 2nd gear was a lot lower. I have the 3.21s. Before, there was no go in 2nd under 2k rpms, but now it actually went. So, to each their own, but I know that I noticed it in 2nd.

JK-KJ

I've done this same thing on just about every other vehicle I've owned and never really noticed much of a power difference....heck, even the actual cold air intakes don't really add much power (maybe 2-3 at the wheels)......but I've always done it anyway just cause it sounds cool. I'm sure I'll end up doing the same on the JK, just haven't had time to mess with that yet.

mkjeep

Drilled 12 1/2 in holes in my airbox removed air horn and did a drop in K&n air filter. Very noticeable pick up on the low end. Didn't like the sound with the stock filter K&n is a little better. CAI for Christmas maybe. Also, take your hardtop & doors off, I think they built the 4-door to run like this

RedRockJK

Drilling holes in the stock box should help it breathe better. Dropping in a K&N at the same time would be a good mod IMHO.
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IGOFSHN

I run a k&n cone type and there is no increase at all. Total waste of money. The only benefit is it will last forever. I would say cutting holes in the air box will be just as good. Absolutely no benefit.

VBS4

Well to add to my above post, I removed the 2.5 section of accordian hose and added a 3" in diameter pipe.
I've driven on it for about 2 weeks now and I've come up with some results.

For several weeks I monitored (per the dash readout) my mpg on a stretch of highway (aprox 40miles one direction). It stayed consistent each time I did it. I then modified my airbox as posted above. On that same stretch of road (flat/straight/long) I've gained 1.5 - 2 mpg on average (this has also stayed consistent on each trip).

As far as power, it feels like there's a little more there but I have no way to test that.

flyer415

It really is in the laminar air flow in the hose. Sure, sucking more cold air can help but the airflow has to stay laminar not turbulent in the ducting. Four years as a test pilot and the only thing I remember is that turbulent airflow will kill you. The real cost for the CAIs is in the piping. Fix that even DIY like VBS4 did and you will notice a real difference. The drilling will give you something even if it is just satisfaction.

mrsig

Sorry for thread jacking but: The best snorkel system is out! Look at my JK@
http://www.aaof.us/jeep.htm