I stumbled on this video from Engineering Explained who is a favorite of mine. He experimented with both the stock filter and a K&N drop in filter. He got dyno numbers and acceleration times of how they performed with and without the charcoal mesh filter inside the air box. Take into consideration this was on a subaru crosstrek, so the results will likely vary on other cars......
I decided to give it a go on my BRZ and made a quick "How to" for anyone who is interested. Its super simple and Im sure most of you could figure it out without any help, but some may want to see it.
1st loosen the inlet pipe clamp shown in red with a 10mm socket or phillips screwdriver. It does not need to come off, just be loose. Also unclip the harness for the MAF sensor shown in blue.
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Next you will want to release the harness from the air box so you dont yank on the wires while trying to remove it. Pinch the tabs of the clip shown in yellow and push the wires free from the airbox. You can do this with your fingers or I used some needle nose pliers.
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After that move over to the lower right area of the air box and locate the 10mm bolt shown in white. Remove the bolt and set it aside. There is no nut on the bottom it just threads into the bracket below, so dont worry about anything falling. Also undo the clips shown in purple holding the air box lid closed at this point.
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Now that lid is ready to be removed. simply pull it up and back towards the engine. The rubber intake tube keeps a good grip on the plastic tube inside but just give it some good pulling and twisting. It will pop off and you will be left with this.
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This goofy thing is said to be for emissions control for air that comes out of the pcv system. I honestly dont think it does a darn thing other than become a restriction. The carbon filled mesh on ours is not held in the same as the one shown in the video. Ours is heat welded directly to the plastic air box. I just grabbed one edge with pliers and pulled it back until I could get a couple fingers behind it. From there just go around and pull until all the welds release and the mesh comes off. It does leave a bit of shaggy mesh behind, so I went over all the welds with a razor blade to clean them up a little. I did not spend a ton of time here because nobody will ever see it. The important part is just to remove any loose bits and shavings from the inside before puting it all back together. This is does after all sit behind your air filter, so any junk you leave there will get sucked into the motor. This is what mine ended up looking like after I was done.
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Thats it..!! Just reinstall the box the same way it came out. Make sure to put the 2 plastic tabs into their alignment slots on the bottom 1st. Stick the plastic tube back into the rubber intake hose all the way. There is an alignment mark so you can see when it is all the way on. Tighten everything up and most important.... plug that MAF back in...!!
I only drove around for about 10 min after. I cant say I noticed much so far. There is definitely a little more intake noise which I did not expect. Not sure how much power can be expected by doing this, but I can guarantee that mesh is not doing us any favors. Let me know what you all think...!!
I decided to give it a go on my BRZ and made a quick "How to" for anyone who is interested. Its super simple and Im sure most of you could figure it out without any help, but some may want to see it.
1st loosen the inlet pipe clamp shown in red with a 10mm socket or phillips screwdriver. It does not need to come off, just be loose. Also unclip the harness for the MAF sensor shown in blue.
Next you will want to release the harness from the air box so you dont yank on the wires while trying to remove it. Pinch the tabs of the clip shown in yellow and push the wires free from the airbox. You can do this with your fingers or I used some needle nose pliers.
After that move over to the lower right area of the air box and locate the 10mm bolt shown in white. Remove the bolt and set it aside. There is no nut on the bottom it just threads into the bracket below, so dont worry about anything falling. Also undo the clips shown in purple holding the air box lid closed at this point.
Now that lid is ready to be removed. simply pull it up and back towards the engine. The rubber intake tube keeps a good grip on the plastic tube inside but just give it some good pulling and twisting. It will pop off and you will be left with this.
This goofy thing is said to be for emissions control for air that comes out of the pcv system. I honestly dont think it does a darn thing other than become a restriction. The carbon filled mesh on ours is not held in the same as the one shown in the video. Ours is heat welded directly to the plastic air box. I just grabbed one edge with pliers and pulled it back until I could get a couple fingers behind it. From there just go around and pull until all the welds release and the mesh comes off. It does leave a bit of shaggy mesh behind, so I went over all the welds with a razor blade to clean them up a little. I did not spend a ton of time here because nobody will ever see it. The important part is just to remove any loose bits and shavings from the inside before puting it all back together. This is does after all sit behind your air filter, so any junk you leave there will get sucked into the motor. This is what mine ended up looking like after I was done.
Thats it..!! Just reinstall the box the same way it came out. Make sure to put the 2 plastic tabs into their alignment slots on the bottom 1st. Stick the plastic tube back into the rubber intake hose all the way. There is an alignment mark so you can see when it is all the way on. Tighten everything up and most important.... plug that MAF back in...!!
I only drove around for about 10 min after. I cant say I noticed much so far. There is definitely a little more intake noise which I did not expect. Not sure how much power can be expected by doing this, but I can guarantee that mesh is not doing us any favors. Let me know what you all think...!!
