# Airbox mod Free power increase



## =WD=big-X (Jan 30, 2006)

Here is an almost free way to get better performance from your 05/06
Frontier,Pathfinder,Xterra. While they have a big airbox,the tube to the 
airbox from front fender it breathes through is quite small and i am certain
restrict the performace and fuel economy of the truck. 

Tools required
10 mm socket, 
6 inch extension
Ratchet
10mm combo wrench
Blade screwdriver
Dremel tool with cutting bit
Small file

1) Open hood.

2) Disconnect the negative battery terminal.

3) Use the blade screwdriver to loosen the hose clamp closest
to the airbox.

4) Open airbox, remove filter, and move airbox cover(lid) out of
the work area.

5) Using the 10 mm socket completely remove the bolt at the top back
of the airbox, loosen the one inside the box near the middle only.

6) With the 10mm combo wrench loosen only the hex bolt at the bottom
front of the airbox.

7) Once the bolt at the back has been removed and the other two 
loosened pull the airbox up and out of the vehicle.

8) Clean your airbox if dirty before you begin the modification.

9) Using the Dremel tool, cut the bottom front of the box out as
pictured. It is easy to do, use the "ribs" inside the
box to help guide the tool as it cuts. Remember to not remove
the larger "ribs" as they support the integrity if the airbox.













10) Different areas may be cut, I feel however the best place to 
remove the plastic is at the front behind the headlight.
More cool air will be available for the engine to breathe in front 
than at the back or side of the box.

11) Once the holes are cut as desired, clean up the edges of the areas
where the plastic was removed with the file. Make sure you get all
the plastic bits and filings out of the airbox before you reassemble it.

12) Reassemble the airbox in reverse order. Install your air filter
(or drop in that K & N you wanted).Put the airbox cover back on.
Retighten the hoseclamp on the intake tube hook up the battery
and the project is complete.

The entire job took about 1/2 hour, provides a small power
boost at low RPMs and a throaty sound at W.O.T. I have performed
this modification to my last 4 vehilces with success each time.This
mod can be done on almost any vehicle easily and inexpensively.

if you have any questions about this mod please feel free to contact
me use MSN messenger by clicking the icon at the left of this post.


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## soberinutah (Jan 25, 2006)

WD, nice mod. Just wanted to ask what are the other rigs you did this on?


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## asrautox (Jan 6, 2006)

=WD=big-X said:


> The entire job took about 1/2 hour, provides a small power
> boost at low RPMs and a throaty sound at W.O.T. I have performed
> this modification to my last 4 vehilces with success each time.


How are you measuring success? Do you have dyno numbers, IAT info., or is it just a calibrated butt dyno with better sound?? Reason I ask is that I've seen this done on a number of vehicles, and in some cases IAT's will increase at slower speeds..


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## capl3790 (Dec 13, 2005)

I thought about doing this but I figured I would spend a lot of time cleaning out my air filter with the influx of dirt and dust being sucked in. What are your thoughts on this?


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## =WD=big-X (Jan 30, 2006)

someone asked what units i had done this on.

1999 jimmy, 1995 pathfinder, 2001 F150, 2005 ford ranger 4.0L
i got the best increase from the 5.4 liter in the F150

another asked about dirt: i run a K&N that i clean once a year. 

i have done this to my last 4 vehicles. we have a gas card lock 
that requires the milage and unit numbers to be entered before
it will dispense gas. we get a printout monthly with the consumption
and mileage from our vendor. so i know it has improved the mileage.
i should qualify that with the fact it is an IMPERIAL gallon not a US
gallon so the increse would be smaller per US gallon

as for the power all i can say is it is noticable towing my trailer through the 
rockies. it pulls up the hill a bit stronger.( this was on the 4.0 L ranger)

i should also note that i had put on a freer flowing muffler too.


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## troyw (Oct 13, 2009)

I finally found something about stock airbox mod for 05' and up Pathfinder!
Whoopie-dooo!

Anyway, I've cut out the whole front section like this, and my MPG readout has shown a decline of 1-2 MPG since doing it. It does feel like it revs up a lot faster and harder. With the motorcycle, I've done lots of mods with an increase in power and gas mileage. Maybe it's just not that way with cars, although I have routinely punched out at least one of the many cats on board and shown an increase in power and mileage there.

Oh, and since there is a stream of cool, fresh air coming in through that space between the radiator and the headlight, every time I've popped the hood to check the airbox temp, it is coooold almost all the way to the motor. So, having just go into the fender like stock doesn't really get all the cool air it can. Imagine that.

Sounds nice though when I romp on it!

- T.


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## Rated_Active (Mar 26, 2011)

IS the power a noticeable change? 


10) Different areas may be cut, I feel however the best place to 
remove the plastic is at the front behind the headlight.
More cool air will be available for the engine to breathe in front 
than at the back or side of the box. (can you show a pic?) thank you


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