Adding induction noise - a immature mod that adds no power (but I did it anyway)

So this mod gives you no additional power. It makes the car less refined, and accomplishes nothing except making more noise.

It also opens your car up to sucking up water at a lower fording height, and probably is not a good idea.

On the flip side, it also does not lose any power.. water fording height doesnt matter to 99% of us, and you get to giggle like a kid when the car makes sucking noises as you floor it.

I am going to describe the mod now, why I bothered doing it, and then the basics of what it does.

I already said its stupid... so I dont need a billion comments about how its stupid.

I also dont need to hear about how its "engineered" a specific way. Yes. it was. I didnt design this one, but I am also an engineer and understand harmonic resonance tuning at a level that I am not going to go in depth on here. if I wanted to design one, for any engine I could. Or the engine itself for that matter. the "specialy enginerded" argument ignores that subaru LOVES pulling from its parts bin, and has goals that might not match specific actual owners.

This giggle-worthy mod is..... removing the white "bottle" chamber mounted under the airbox.

Thats it. its just like changing the air filter, except when the cover is off, You pull out the airbox (two 10mm bolts , and a plastic stud in a rubber grommet)

You then carefully work the bottle off, releasing its clips one by one.

Then reinstall the box.

First... why did I do this? I will have to just drag you along my train of thought.

I was looking for a space to add a vacuum canister for another dumb immature mod.(i'll post it later after I do it) I started thinking about making a carbon fiber intake tube that gets rid of the baffles so I can sneak my dumb vacuum canister where they are. that would work nice as I am tapping the brake booster line as a vac source.

This got me thinking about the induction sound.. and I realized.. this car is oddly silent. hmm. I actually would like some induction noise.. then I went on my day. little bit of time goes by.

well I was looking at the giant flat air intake. It takes in cool air from the high pressure area directly infront of the radiator and goes into the airbox. (that big flat triangle piece)

Hmm. looks small. Is it? I actually measured it.... its the same overall area as the entryway to the airbox.. except. (I then measure the throttle body) wait. the entry to the airbox is smaller than the throttlebody area. thats dumb. Probably doesnt make any difference.. but it bugged me. Then I realized.

I have the 3.6R and I think they designed the airbox for the NA 4cyl..

yup. same part.

So, still not knowing about the "bottle" yet, I look at the airbox location. I dont want to suck in hot air. I could make a new scoop thats taller, as the hood clears by about an inch or so... but then how would I make the airbox hole bigger? I dont want to make a new airbox too.. ugh.

what if I made a new hole? where would I go? Well.. my front wheel has almost an airdam there infront of it.. I wonder if can replace that plastic bottom of the corner with a scoop, then just holesaw in a new intake. add a little airgap so it blows cool air in, but doesnt suck puddle water.... hmm...

And then I removed the airbox. this dumb bottle-chamber is a baffle?! it already has a round hole here too! awesome!

so I pulled that sucker off, measured everything and threw it back in the car without the bottle-baffle for the time being.

started it up... heh. it is making extra sucking noise from the square edge of the "tube" hole... hehehe..

sounds just like my first car after I put a 4bbl carb and 14" round air filter on it. cool.

So thats how I got to here.

what does that bottle do? Its an expansion chamber style baffle. the induction noise goes in, where it meets this large volume (area) to expand... it slows down, bounces, and being tuned length, mostly cancels itself back out. think of your echo. you yell at a rock wall in the distance, and after a second, it comes back... imagine yelling every 1 sec, and your echo coming back and canceling out your second yell with the first.... except instead of having a large distance, we are slowing it by having it expand, and tuning it with the narrow inlet length.

Hopefully that makes sense.

in anycase.. go pop the hood of your car, and look under the airbox.. there is the white "bottle" that makes it silent. if you pull it off, it makes noise.

your car isnt getting any meaningful amount of additional air at wide open throttle. its not faster. but.... its also not a tuned intake length for more power/efficiency or anything like that so you're not losing anything either... but it is a air intake facing downward.. so... dont dip it in water. it SHOULDNT suck up water since the normal air intake is still there.. but I still wouldnt do it if you cross water.