Write-Up: Gutting the Stock Air Box

i didnt see any effect on mpg when i gutted mine, but K&N and all the intake companies claim it increases fuel econ since it gives more hp.

but if you have a 95 like mine you should lookinto rplacing the factory rubber tubes baffles there are the ones on the side and more of the stupid things on the bottom

Ok i plan on gutting my airbox. after gutting the airbox what is the best way to keep the bottom portion attached because i dont like the idea of drilling a small hole in the airbox and attaching it with a zip tie.

I found there's no real need to tie down the airbox. It really isn't going anywhere with the ducting tightly clamped to the TB and box. Mine does not bounce around at all.

Would sure be nice if you'd add some basic information about your car to your signature so we know what model we're dealing with. The 95-99 cars have many differences.

AA wrote:

Yes, but it has to be controlled. I believe the WRX STI has an OEM water injection system... works like N2O, but to a lesser degree.

Please don't inject water into your intake unless you know what you're doing.

So should I take this out of my intake tube?




Do they have any aftermarket kits designed for other cars?

it would probably need to be custom. my friend has water injectors on his regal. i will take a look at how he has it set up this next weekend.
btw he is running 10's, so it must work.

so as not to stray from the topic:

texasfan010 wrote:

Ok i plan on gutting my airbox. after gutting the airbox what is the best way to keep the bottom portion attached because i dont like the idea of drilling a small hole in the airbox and attaching it with a zip tie.

it should hold in place just fine the bottom of the box should still be held in by at least one or 2 tabs toward the engine. if you need a K&N drop in, let me know.

Lol.. I dropped one of my airbox screws somewhere in the lower brace and cannot find it.
I need the smaller of the two that hold the airbox down. (the one closest to the front of the car)
Thanks,
-brady'

Because this isn't a forum I check as often as I should, please feel free to email me at
dj underscore brady at email dot com. (dj_brady)

I lost one of mine and found a replacement at Lowe's in the hardware section. You can take the other screw in and find the replacement.

the heads are different sizes... but you're saying the threads are the same? (I guess I had an attack of retarded.. I don't know why I didn't try the remaining screw in the other hole.. lol)
Thanks for the heads up Aaron!

Actually, you may be right. Double check it in the other hole before you buy.

Mine broke off and I drilled it out, so not sure exactly what size it was!

ahh.. heh.. the plot thickens.. Yeah, I'll just compare to the other and then get a handful at lowes in a similar size.. It's no HUGE deal, but now it rattles at startup and over some bumps (and if you know me, you know I HATE rattles and squeaks). lol.
While I've got you here, Aaron... have you ever replaced the felt window guides that are located just under the lip of the window? I need to replace these before I get my windows tinted but I don't know what the part's called (and the buick dealership was of surprisingly little help)

Okay, I started to gut my airbox today. I got the top off just fine but the bottom was an entirely different story. The write up neglected to point out the sizes of the bolts so I had to sort through some sockets to find the right size (10mm for the one on the firewall side and 6.5mm on the front end side).

The tiny 6.5mm one came off just fine but the 10mm just kept spinning on me. I thought I broke the 10mm loose but it turns out I broke the weld or whatever held it in place. It has a square lugnut on the other side of it that just spins with it now and I cannot get it to come off (Nice and rusted on). Fortunately there is a hole that I can reach the other side of the bolt with but I can't get a wrench or anything in there to hold it in place so I can take it off.

It's really ticking me off. How else can I get that bottom piece out? Can't I just break that grey plastic thing without taking it out? Any advice on how I can get that bolt out?

Also, I want to know - how is removing that grey plastic thing helping? For that matter, how does taking the red part out help? Also, while I'm thinking of it what is that sensor that is attached to the box?

You might be able to reach that problem bolt with your fender cover off. Taking that off is only a matter of popping out 10 or so of those black plastic tabs. then you might have the access you're looking for.

The gray plastic thing is just a baffle, for sound. Just take it out (it's not stuck in there, is it? You should be able to just slide it out).

I think taking the grey plastic shitter out of there allows your box to draw more air from the fenderwell area. And removing the red plastic thing (which you WILL have to break, if I recall) just increases the amount of air that will be going through your intake.

The sensor that is attached to the box is your IAT sensor - it tells the computer the temperature of the air going to the throttle body, so it can adjust the fuel and... well, stuff. Other people can probably explain that better.

Anyway, gutting frees things up a little. You'll notice some intake noise, and some supercharger whine, but it should still be close to stock. If you're really going for the whole shebang, you can take out that little compartment on the intake tube. I think that's just a silencer too.

If you want, I can sell you my drop-in K&N filter. I just upgraded to a FWI with a K&N, so I have no need for the drop-in. It only has 4k on it if you're interested.

Thanks Ben! Appreciate the offer but I've already got a filter (I think it's a FRAM). This is only temporary anyways until I can make a CAI. I thought of taking that cover off it's just a pain to do it.

Okay ripped that shroud off and I still can't get to it. I can see EVERYTHING else BUT the other side of that bolt. I can even see the under side of the grey cavity thing. What can I do? I'm about to start breaking stuff, I'm so sick of this.

I just did mine a couple days ago and I found the "bolt" on the front of the airbox, towards the bumper, was not a bolt at all. I just pulled it up and popped the box off. then I pushed it back down and it popped back in. Now I don't know if that's how it's supposed to be or not, but it went back just like it was before I gutted it. the rear bolt was a REAL pain the A** to get off on mine too.

The front one was no problem, it came off with ease. I'm having the problem with the rear bolt just like you did. I'm thinking about just cutting it with an air tool.

Alright, finally finished gutting it. Had to take a dremel to the grey thing and saw it to hell. It finally came off after tearing up one of the blades. Biggest PITA if you can't get the airbox to come out of the car. Even tried using the dremel on that bolt and it was just not going to cut it.

Difference wise, I can definately hear more of the S/C whine. My dad being the negative to anything that I like says "Oh boy that made a huge difference didn't it? Now it whines more, so what? Who want's to hear all that noise anyways?". He seems to think that if I ever went to get rid of my car someone would hear that whine and go "UH OH, What's wrong with it? That whining sounds like something is broke!". As if "It's supercharged, they are supposed to do that" wouldn't be a sufficient explanation to any tard who'd think something was broke...

I gave it a little bit of gas on the expressway and I can hear the S/C more at lower throttle levels as well as WOT. Despite the fact this didn't go as planned I'm still satisfied enough with the whine. At least until I can get the time and patience to build a CAI/FWI.

Shintsu, it's not supposed to be about the whine, although that is a nice side effect. It's supposed to be about lowering IAT by drawing more fenderwell air through the holes. Did you notice any drop in IAT as compared to actual OAT?

Well, I don't have anything to actually monitor the temperature other than the gauge on the car for the motor. I never went to the trouble of buying any kind of tuner or anything for mine since I can't change the shiftpoints. I will say that the car seems to run a little smoother now, but I'm not sure if that's actually different or just perceived.

Shintsu,

It probably does run a little smoother. You've freed up some room, so your engine can breath a little better without working as hard.

Going from a gutted airbox with K&N drop-in to a FWI yielded similar results for me - I felt as though the engine didn't have to work so hard to get the extra air that it craved.

In other words, I'm sure it's different, not perceived. It makes sense... think of it as unclogging your car's "sinuses."

We could both just be crazy though, but I doubt it.

Not crazy, I thought I noticed the same effect when I gutted mine too.

Shintsu wrote:

I never went to the trouble of buying any kind of tuner or anything for mine since I can't change the shiftpoints. .

you cant change the shift pressure for harder shifts, but you can raise shift points when you get rockers or a cam or at least heavier springs.

You can raise shift points anyway, don't need modded valvetrain as long as you don't go way up to 6krpm. Lots of cool stuff to be done with a tuner for regular driving, not just WOT performance.

i just did mine this afternoon and i noticed a whistling sound at idle, maybe i just dont remember it from before but is this normal?