Has anyone cut their factory airbox for more airflow?

Rayze78 · **Joined:** Wed Sep 12, 2007 8:41 pm **Posts:** 36

I was looking at the factory air box on my 03. I noticed the spout that comes up and turns to the front of the truck pops off separately. I took it off, but didnt notice any difference. So I was thinking of cutting a "window" on the front of the airbox (the front side), and possibly part of the bottom. I would think this would allow for more airflow, without having to buy a cold air kit.

I have done this before on 2 other cars, but they had conical style filters. They were the kind that has the MAF in one half, and the other half houses the filter. On the filter half, I would cut the section in half. It exposes most of the filter, but still allows you to use the housing to clamp everything tightly. Of course, you dont get the smooth piping from the kits, but its better airflow than stock. Both of these had a direct fit K&N.

I currently have the direct fit K&N in my Jeep. I dont see how it would hurt by cutting part of the box, seeing how I have done it before with success. I just didnt know if anyone else tried it yet. As far as being exposed to elements, it wouldnt be any different than a cold air. I dont use it for mudding or ford rivers with it

so I think it would be ok. Anyone else try this?

KeswickDave · **Posted:** Wed Mar 05, 2008 11:11 pm

I suppose it wouldn't hurt as long as you stay out of puddles :wink:

Some of us have been discussing (and some doing) variations of a modification to duct more air into the airbox - see here:

http://www.lostjeeps.com/forum/phpBB3/vie ... highlight=

Dave

tommudd · **Posted:** Wed Mar 05, 2008 11:19 pm

I just run a 4 inch flexable dryer vent hose out to the grill with a larger hole cut where the original intake went in, works well so far

Rush345 · **Posted:** Thu Mar 06, 2008 12:58 am

Personally I have the stock air box and I did this Mod from: MonsieurGlen it's easy and cheap. But I use an Amsoil Air Fiter , I drove for a year with the K&N air filter. But upon replaceing it with the Amsoil stock Air Filter saw a difference. as to the ducting of the Air intake: http://www.lostjeeps.com/forum/phpBB3/vie ... c&start=15
Check out the PVC Pipe intake system it works pretty good., I truthfully haven't fully test the system out , But the ScaanGuage I, I use reflects an increase in gas milage and a noticable seat in the pants feel of increased performance.. I am rather pleased with the general feel of this modification. I find it effective and efficient. :twisted:

Rayze78 · **Joined:** Wed Sep 12, 2007 8:41 pm **Posts:** 36

Thanks for the tips and links. I may be doing some cutting this weekend

WV Jay · **Posted:** Thu Mar 06, 2008 9:09 pm

When I had my Tacoma, I installed a 4" deckplate in the front of the air box. I haven't looked at the KJ's box to see how it's made yet, to ses if this would fit. It has a cap to screw on to make it factory like for water issues. They come in 3,4 and 5" diameters. Here's a link on how to install it on a 3.4L Taco (forgive me, lol) http://www.customtacos.com/tech/index.php?article=85 If this would work, you could run a tube directly to the deckplate or just inside the box.

tommudd · **Posted:** Thu Mar 06, 2008 9:41 pm

WV Jay wrote:

When I had my Tacoma, I installed a 4" deckplate in the front of the air box. I haven't looked at the KJ's box to see how it's made yet, to ses if this would fit. It has a cap to screw on to make it factory like for water issues. They come in 3,4 and 5" diameters. Here's a link on how to install it on a 3.4L Taco (forgive me, lol) http://www.customtacos.com/tech/index.php?article=85 If this would work, you could run a tube directly to the deckplate or just inside the box.

I was just reading about this last night over on one of the Tacos forum, ordered one of the 4 inch deckplates to try it out, will let you know in about a week

WV Jay · **Posted:** Thu Mar 06, 2008 10:15 pm

Good deal! Let me know how it goes and I'll definately go that route. I noticed a decent power gain paired up with the flowmaster on my Taco (2.7). I found out about it over at TTORA.

kvenner · **Posted:** Fri May 09, 2008 3:30 pm

tommudd wrote:

I just run a 4 inch flexable dryer vent hose out to the grill with a larger hole cut where the original intake went in, works well so far

tommudd: Do you have any pics on how you installed this?

Rush345 · **Posted:** Fri May 09, 2008 8:38 pm

The Taco gives a cleaner application then my use of the 2" PVC set up needed losts of RTV to cover my sins. But I like the pipe comming out just behind the grill and I added one other Mod by covering the inlet PVC with screen wire held in place with a hose clamp. This prevents the introduction of insects and such and I still have a pipe cap for water situations.

surfRenegade · **Posted:** Thu Dec 17, 2009 8:13 pm

I have never noticed an ounce of gain by putting any CAI on a vehicle. The only thing I noticed is a little more noise and my MAF getting oil on it from the oiled cone filters. In many cases people did testing. actually put a small device in to measure air flow and the stock intake did better than any thing else. Id say leave it alone.

tommudd · **Posted:** Wed Dec 23, 2009 10:06 pm

surfRenegade wrote:

I have never noticed an ounce of gain by putting any CAI on a vehicle. The only thing I noticed is a little more noise and my MAF getting oil on it from the oiled cone filters. In many cases people did testing. actually put a small device in to measure air flow and the stock intake did better than any thing else. Id say leave it alone.

best bet for the Liberty is the stock box Amsoil filter and a 3 to 4 inch hose to the grill, thats after testing several setups over 100,000 miles on mine!
CAI are a waste of $$$$$

KJKev · **Posted:** Tue Dec 29, 2009 11:29 am

But seriously.

How is more air flow going to help when the computer is set up for a specific amount of air flow into the engine?

Or can you flash the computer to allow more air?

If not, more air, same amount of fuel = leaner fuel mixture=burn pistons.

What am I missing?

tjkoen01 · **Posted:** Fri Feb 26, 2010 11:16 am

KJKev wrote:

But seriously.

How is more air flow going to help when the computer is set up for a specific amount of air flow into the engine?

Or can you flash the computer to allow more air?

If not, more air, same amount of fuel = leaner fuel mixture=burn pistons.

What am I missing?

the computer uses the o2 sensors to detect if it is running rich or lean or ideal. it uses this feedback to change the pulse width for the fuel injectors to control the a/f ratio. the computer also uses input from other sensors to control the a/f ratio (engine temp, map, tps, etc.), but is ultimately set by the o2 sensors once it is in closed loop mode.

as long as you are not forcing air in, the computer can manage pretty well on it's own. chips and flashes may be able to make better use of more air, but the stock computer can take advantage as well.

so to answer your question, more air = more fuel = more go!! :pepper:

BVCRD · **Posted:** Wed Mar 24, 2010 11:21 am

KJKev wrote:

But seriously.

How is more air flow going to help when the computer is set up for a specific amount of air flow into the engine?

Or can you flash the computer to allow more air?

If not, more air, same amount of fuel = leaner fuel mixture=burn pistons.

What am I missing?

The engine will only draw in what air it needs. You could take the air box off and throw it in a creek, and the crd will only draw the same amout of air. It takes what it needs. Some systems that are restrictive actually starve an engine. Opening them up can help as long as you don't create a lean condition. CRD isn't one of those.

monkyfart13 · **Posted:** Mon Jan 03, 2011 4:40 pm

tommudd wrote:

surfRenegade wrote:

I have never noticed an ounce of gain by putting any CAI on a vehicle. The only thing I noticed is a little more noise and my MAF getting oil on it from the oiled cone filters. In many cases people did testing. actually put a small device in to measure air flow and the stock intake did better than any thing else. Id say leave it alone.

best bet for the Liberty is the stock box Amsoil filter and a 3 to 4 inch hose to the grill, thats after testing several setups over 100,000 miles on mine!
CAI are a waste of $$$$$

thats exactly what i ended up doing.

Has anyone cut their factory airbox for more airflow?

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