DIY: Airbox mod - Cool Air Injector (anti-56k)

Old 10-22-2008, 09:50 PM
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Lightbulb DIY: Airbox mod - Cool Air Injector (anti-56k)

Edit: After some suggestions in this thread i got larger diameter piping and have updated the DIY accordingly... enjoy

this is a simple modification, that only cost about $12, took roughly 25 minutes total, and that i hope will redirect some outside air into the stock airbox, which i believe is best for these cars.

Here is all that you need, PVC conduit elbow 1-1/4'', pvc 45 degree elbow connector, 2x2 plastic flashing. (flashing was on the top shelf above the pvc fittings at Ace)

conduit elbow (pvc)
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45 degree connector for 1-1/4'' pvc
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plastic flashing
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before I left the store, I made sure everything fit. the fitting fits on the end of the pipe, and should fit snuggly in the rubber seal on the flashing.

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first i turned the wheel all the way to the right, and removed the wheel liner, like you would do if you were changing the bulbs in the driver's side headlight

under the stock airbox, is a resonator bottle that looks like this
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it goes in here...

i used an 8mm wrench to remove the two bolts holding it on, and pulled it down, to dislodge it from the airbox. it should look like the above pic when out.

after that i pulled the big piece of foam out a few inches, so see where it was connected..
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it's held in by that big black plastic square, which is held on by two easy clips, one was fairly obvious, and easy to reach.

the other i had to reach through the lower part of the front grille with a screwdriver,
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i broke my foam taking it out, but what the heck. i can get more foam.

next, I fit the plastic flashing piece against the front (lower) grille, so that air will trap in there. I was able to secure mine by putting the top flap between the plastic box piece (that sits above the foam), and the grille.

insert it like that^, then bend the flap nearest you on top and pull it through the bend of the box, and pull the whole piece toward you to line up with the pipe... this should wedge it and secure it real tight...

you'll know what i mean when you get under there...

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the 45 degree elbow is to make the required bend to reach the flashing. i had to size it up before determining the proper way it should face before tightening it on.

after i decided which way to face the connector, i tightened it on the pipe, and pushed it through the rubber seal on the flashing almost all the way through, still with the pipe turned sideways like so...

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then i turned it upward to reach the airbox hole.

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I wanted to try and make sure and push the pipe through enough so that when i inserted the other end into the airbox, it pulled back out a little from the flashing... this way the rubber seal goes inward toward the pipe, creating more of a funnel effect. the bare end of the pvc pipe should fit very snugly into the hole on the bottom of the airbox, though you may need to wrap it with some tape or something... it should go all the way up into the airbox like so.
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... it should all be very nice and tight, but of course that's what she said.

Coupe fitment pic courtesy MikeGrote (See post #70)
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disclaimer: i am not responsible for anything you do to your own car, nor is this description of what i did, in any way, an encouragement to do, or endorsement of what i did. i'm simply telling a story.

Last edited by UR2EZ; 04-08-2013 at 02:35 PM.
Old 10-22-2008, 11:03 PM
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Interesting, did it change the sound at all?
Old 10-22-2008, 11:45 PM
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doesnt seem like it would do much
Old 10-22-2008, 11:53 PM
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You'd want some kind of velocity stack or collector down there for it to be truly effective... larger piping wouldn't hurt either...
Old 10-22-2008, 11:59 PM
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abysmal gains. You need larger piping
Old 10-23-2008, 12:21 AM
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That hose/piping is so small I don't see how that will do much, if anything.
Old 10-23-2008, 10:21 AM
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Thumbs up

Hey, +1 good idea. I agree with some sort of collector down there and large piping to catch more air. but awesome concept. Keep us posted.
Old 10-23-2008, 10:58 AM
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will do; i'll be going back up to ace hardware tomorrow to find some kind of funnel i will use to attach to the end of that hose, and to the back of the grille. hopefully that will direct some major air when at speed. and yes the tubing is kinda small, but the airvolume is prolly about the same as the 'power-duct' since it doesn't have a very big opening to the outside... the airbox just seems blocked from the two directions it gets airflow... this will add a third air passage, and it should be more effective than the oither two, since it's directly in the airflow

edit: i got the larger piping, and updated the OP with new pics.

Last edited by UR2EZ; 10-24-2008 at 10:27 PM.
Old 10-23-2008, 01:19 PM
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I think this is the beginning of a very good idea.

Somewhat like that duct that the Z guys put through their bumper, if we put a larger hose and a finished looking duct there, it would look decent and would have more function.

Since it's not the only hole, I don't think water would be a problem...

Old 10-24-2008, 09:22 PM
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MOD COMPLETED!!! i went back to the store to get bigger piping, and when i tried to rig it up, the larger piping fit perfectly by itself, into the stock airbox hole. no connectors needed!! i only needed one connector to bend toward the 'funnel', which i used plastic flashing for.

you guys inadvertedly made this mod work, by suggesting larger piping.

the DIY has been updated and is now complete

Last edited by UR2EZ; 10-24-2008 at 10:27 PM.
Old 10-24-2008, 10:39 PM
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cool nice little DIY you did
Old 10-24-2008, 10:44 PM
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ummmmm, why no just go with a CAI? The have a much larger diameter tubing and it gets rid of the restrictive stock air box.
Old 10-24-2008, 10:45 PM
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dude, good thinking even if it doesn't give 400 extra hp it can't hurt.

Try larger pipes and paint the tip so it doesn't look like white PVC pipe stuck in your G, LOL.
Old 10-24-2008, 11:21 PM
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Originally Posted by SDGeneralCounsel
ummmmm, why no just go with a CAI? The have a much larger diameter tubing and it gets rid of the restrictive stock air box.
CAI don't do squat. This is just a way of redirecting cold air without having to go with a long-ram intake setup.

IMO, its a great approach.

Old 10-25-2008, 12:33 AM
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Sure that's going to work. At least, it would duct colder air into the air filter + $13 won't hurt our thin pockets. Great job.
The following 2 users liked this post by JSpec350GT:
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