DIY Swiss Cheese Airbox Mod

[Roca]

I've removed the snow catcher & dropped in the K&N panel filter.

FYI; I had the injen sp intake, that was junk, then I got the Autotech closed intake, not junk but not worth all that money IMO, so trying this out now.

Step 1; removing front lid & drilling some holes (not sure if this did anything)


Step 2; drilling holes in the airbox, might have made it a tad louder but nothing really noticeable



Step 3; larger holes, still nothing has changed




Step 4; made larger cuts on back & side away from engine where I'd previously made smaller cuts. result seems the same...

end result, more sound, same power (butt dyno tested only), makes it a bit more fun to drive but not worth all the hassle lol

waiting for other stock airbox to come in so I can put it back it and throw away this one...

might go back to injen just for the summer fun

 

[Roca]

no one at all interested in this? lol

 

[Tatanko]

Back in my Maxima days (I owned three VQ-powered Maximas in high school & college), I spent a looooot of time working on all the various parts of the intake system chasing small gains and probably learned more through failure than success I would say. In that regard, I definitely encourage you to play around because it's both fun and educational. That being said, here are my thoughts and questions based on past experiences:

1. How much of a restriction is the stock intake system really? I'm still fairly new to the VAG world (and German cars in general), but most OEM intakes these days don't leave much on the table for performance gains. They are almost always tuned to provide maximum performance with minimal noise, the exception being dedicated performance vehicles where extra sound is preferable.

2. What other modifications do you have done to the intake & exhaust sides of the equation? Anything at all (even something like a turbo muffler delete).

3. What is the intended benefit of the extra holes in the air box? If it's to allow more air into the system, it may be worth your while to concentrate on the scoop instead. You want cold air from outside the car, not hot air from the engine bay. Since you have an extra factory intake, you could try crafting your own larger scoop and a larger opening in the air box to match it.

4. Are you going to be doing any semi-scientific measurements? Without data to compare, you may never know the actual results of your efforts. You'll want to compare pressure, intake temperatures, etc.

 

[Sandman GTI]

I suggested on another thread that you insert a hose to the air box and run it to the cabin to see if you get induction noise like I understand they do in the new Mustang. Would not have to get complex. Remove the gasket on the back of the engine that seals off the hood. (you can see if just removing this helps with noise. Then run a hose (1 inch maybe - garden hose piece) from the air box thru and under back of hood and just run into side driver window. Then while you drive listen to see what it does.
If it works then decide how to run thru fire wall and what hose to use.

As far as other holes. I would cut toward the driver to direct noise that way and cut on the intake side of filter as cutting below it would bypass the filter and I think that would not be good. What ever you cut out make sure you remove and trash so it does not go into intake to engine.

 

[Roca]

on these intakes the air goes from below then up into the filter and to the turbo so def not cutting out the top part, I'm not sure if you're f*cking with me lol

 

[Roca]

Tatanko, it's really just for fun, see if it changes anything and if I can hear the spool/whoosh a bit more, I don't want to be trying to measure anything, just testing it out

 

[2slowvw]

If all you are after is the noise then I guess go for it. If you are after gains.... i'm going to say it is a fools errand.

 

[Roca]

no need for gains, useless to me lol

 

[mkygod]

This totally reminds me of..

 

[Sandman GTI]

on these intakes the air goes from below then up into the filter and to the turbo so def not cutting out the top part, I'm not sure if you're f*cking with me lol

Not sure who you intended this for but I am not.
I may have suggest wrong info as I thought you had a spare filter box but sounds like you are cutting the long air intake box.
Many have changed what you are working on. Not sure any benefit.
Just take the top lid off. If no more sound then holes likely will not help.
Sounds like you want a filter on a stick for intake for noise.

 

[Roca]

yeah but I'm trying things for fun at this point lol
you meant the lid of the front part that I just drilled up?

 

[Roca]

drilled some holes in the bottom part, seems to be louder, will go for larger holes tomorrow and post pics of the holes I made before & after (smaller then larger)

oh and not sure if it's the caffeine or my mind is playing games with me but I do feel a difference lol

 

[nkresho]

I see you have the k&n in your sig. I'd caution anyone thinking of doing this and running a paper filter. You're definitely going to get some rain directed through the front holes, right on the filter. Won't really hurt anything in the short term, but it may drag some dirt through the filter with the water.

I think the best path would be to mimic other aftermarket intakes with the mods. If they open the front, then do that. If they redirect air in other ways, do that.

One think with water is that you want the air to flow freely, but you want the water to hit some sort of baffle and have to travel uphill along a wall to reach the intake, effectively slowing it's path to the filter (or giving it time to evaporate). That's why the stocker draws air from the underside of the passenger side of the car. Water will have to run all the way along that piece, then downward to the bottom of the airbox, then along the walls of the airbox, and eventually to the filter. This keeps the droplets from making it to the filter (for the most part).

What I see with the opening of the front is the path to the filter is now linear. In the holes, then straight up to the filter. With intakes like APR, the filter is free-floating in the middle of the housing. This would efectvely keep the water on the outside of the housing, at the bottom from gravity, not really allowing it to make it into the filter.

Regardless, I trhink it's cool that you are experimenting. And, with the foresight of grabbing a spare box, that's how I would have done it too. Keep an eye on the tubing, post-airbox. If you get dirty streaks of dried water, you may want to back it off a little. That would show that water is making it through the filter and it is bringing dirt with it (silica). Long term, this is not what you want.

Keep up the good r&d though.

One recommendation I would make, with regards to the water, is to put some sort of baffle behind the front holes, to stop the water and redirect it downward. This would allow similar flow, but might reduce sound a little (not what you were going for). You could then remove all the material where the holes are. You could trace it while that part is ojn the car, then cut with a dremel off the car. This is the type of bit I would use.

Perfect for drilling in and making clean cuts. Just need a steady hand to keep it from looking like cursive.

 

[SpeedieGTI]

Really a pointless venture...are people this bored?

 

[nkresho]

I don't expect to see any power increases. Decreases actually, more likely.

But, if the primary goal is a sound increase, I think he may be on to something.

That said, while I am being encouraging, i'd never do something like this to my own car (even if it was a lease).