# factory airbox ?



## LARRY01Z28 (Dec 4, 2010)

ok i have a question, why cant you take the factory lower air box and just cut a section of it out. you will get more air into the airbox, and it would have to be louder. 
ive done this mod on the 99-07 silverado trucks and it has always helped those trucks out. its kind of like opening up the intake for free.

also what is the little hose that connects to the lower air box? what does it do?

thanks for all the help and your thoughts.


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## CHEVYCRUZE RS (Mar 29, 2011)

Are you talking about the tubing that drops into the fender ? For the factory airbox correct?


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## LARRY01Z28 (Dec 4, 2010)

no, its a little tube that is about 3/8 thick and it plugs into the lower front right side of the lower air box. i already pulled out all of the factory silencer stuff that runs to the front of the car.


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## LARRY01Z28 (Dec 4, 2010)

the little tube in this pic, that has the little ridges in it. it hooks into the intake. but im wondering what it does?


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## LARRY01Z28 (Dec 4, 2010)

its the tube that is kind of pointing to the motor mount.


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## shawn672 (Oct 31, 2010)

Vince said not to mess with anything before the air straightener or it'll do funky things to the MAF


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## WHITECO (Mar 31, 2011)

That looks like a pcv line


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## LARRY01Z28 (Dec 4, 2010)

so how is cutting the air box to get more ait into it going to mess with the MAF? 
it will still be metered air going thru the MAF and into the motor. it will be no different
then putting a cold air intake on would it??


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## LARRY01Z28 (Dec 4, 2010)

so when i pulled out all of the front piping and silencer in the fender well i shouldnt have done that?


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## Jim Frye (Mar 16, 2011)

I did a similar trick on our '03 Protege5. I drilled a 2 1/2 inch hole in the side of the lower airbox, under the filter. I attached a flange to the outside of the airbox and ran a 2 1/2 inch hose down between the fender liner and the front cross member. At the bottom there is an access plate to allow you to get the back of the fog lamp assembly. I modified the plate to let the hose get air. I left the OEM air intake which ran over the cross member and behind the grill in place. The OEM pipe is really flat where it passes over the cross member and under the hood, like the Cruze pipe is restricted. It made a difference in noise, throttle response, and boosted mpg a bit. Actually, it made a huge change in throttle response. All you have to do is just toe the pedal and the motor jumps. It was pared with a K&N drop in also. The ECU seemed to handle the change with no issues. The motor is NA.


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## LARRY01Z28 (Dec 4, 2010)

i think ill try it and see what happens. i mean i can always buy a lower air box if it doesnt work.


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## slecyk (Mar 12, 2011)

Yea I don't know what that tube is for either but I'm trying to install a SRI and that piece is the only one keeping the lower part of the air box on. Anyone know how to remove that tube?


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## LARRY01Z28 (Dec 4, 2010)

I dont know. im going to have to trace it and see where it goes. i jus thavent had the time to do that yet.


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## Vetterin (Mar 27, 2011)

Regardless of what that tube is (but I'm thinking EGR also) if it only connects to the bottom of the air box it should have no effect if it's not connected to the airbox. As far as cutting the bottom out of the air box, that is a pretty common mod for many car owners. It was one of the first mods many of us C4 Corvette owners did as our air box is right in front of the radiator, only difference being that we cut the front out. No problems should be encountered.


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## LARRY01Z28 (Dec 4, 2010)

Vetterin said:


> Regardless of what that tube is (but I'm thinking EGR also) if it only connects to the bottom of the air box it should have no effect if it's not connected to the airbox. As far as cutting the bottom out of the air box, that is a pretty common mod for many car owners. It was one of the first mods many of us C4 Corvette owners did as our air box is right in front of the radiator, only difference being that we cut the front out. No problems should be encountered.


 
thats what im thinking. on my 01 camaro it is a free mod. 
im going to cut it and see what happens.


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## LARRY01Z28 (Dec 4, 2010)

OK Ive cut the factory air box. ill try to get some pics. lets just say it is def worth it. i can here the turbo spooling up better and the bypass valve is def louder. 
no codes yet so i dont know what anyone is tlaking about on the maf freaking out???
im going to try and scan it and do some logs with autotap if it will work??


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## Seko (Jan 17, 2011)

I really want to see those pics


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## Vetterin (Mar 27, 2011)

I checked out that tube today on my car and...........it doesn't connect to ANYTHING! It's like a drain tube that is maybe 12" long and just stops along the wheel well. At the end is a little rubber drainage fitting. You could just remove the entire tube if you want without any problems.


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## 70AARCUDA (Nov 14, 2010)

...is it either: (a) drainage for condensation buildup inside the intake runner system, or possibly (b) a/c condensation drain?


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## Skilz10179 (Mar 22, 2011)

Vetterin said:


> I checked out that tube today on my car and...........it doesn't connect to ANYTHING! It's like a drain tube that is maybe 12" long and just stops along the wheel well. At the end is a little rubber drainage fitting. You could just remove the entire tube if you want without any problems.





70AARCUDA said:


> ...is it either: (a) drainage for condensation buildup inside the intake runner system, or possibly (b) a/c condensation drain?


Thats very odd, i've never seen that on a air box before. I thought for sure it would be for positive crankcase ventilation...

Good info!


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## 70AARCUDA (Nov 14, 2010)

...those were questions.

...I asked because the air cleaner assembly on my 340/6BBL had two "drain" tubes with rubber hose extensions that directed any water coming into the hood scoop to drain out past/beyond where the exhaust manifolds/headers were.


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## slecyk (Mar 12, 2011)

Yea I noticed that too when I installed my SRI. Doesn't connect to anything and is held in place with two cable ties. Pretty weird.


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## Jim Frye (Mar 16, 2011)

The air box on my Saturn had a small, short tube at the bottom with a little rubber valve to let water out, but not in. I never noticed water inside the air box in all the time I had it.


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## LARRY01Z28 (Dec 4, 2010)

yeah i traced mine today to. it goes no where so it will be coming off. ill try to get the pics up soon. ive got 900 miles on the car since cutting the box and no codes and it isnt acting up or anything. my wifes has the car this week so ill get those pics up this weekend ok.


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## Seko (Jan 17, 2011)

what kind of job you do on your airbox. Just making some hole for the air ou unplugged the tube?


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## LARRY01Z28 (Dec 4, 2010)

i cut over half of the bottom out of the airbox. so its def. breathing now.


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## bladegear24 (Mar 2, 2011)

can u please post some pictures?


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## LARRY01Z28 (Dec 4, 2010)

im out of town right now. but i will post up pics as soon as i get home.


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## Seko (Jan 17, 2011)

so..... if I understand...... IF I drill 5 or 6 holes 2 inch each It wil be ok??


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## vitgia78 (Mar 9, 2011)

Hi there, is this picture true?


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## shawn672 (Oct 31, 2010)

vitgia78 said:


> Hi there, is this picture true?


Yes


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## osiris10012 (Feb 4, 2011)

vitgia78 said:


> Hi there, is this picture true?


wouldn't it be more beneficial to just remove the lower section (white section in pic) and leave the upper section in? I would think that this would be a better solution for noise and cold air because removing the upper section creates a gap between the air box and fenderwell allowing hot air from the engine bay to enter.


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## vitgia78 (Mar 9, 2011)

Yesterday I removed the black pipe in the picture. It's wonderful, the lag seems to be destroyed at first gear, gas pedal is smoother. No more noise, the air is colder than air from engine bay. Torque is lower than normal. I can easily get 80km/h with 1,600 rpm (2,000 rpm before).


















(Sorry about our language at the picture)


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## LARRY01Z28 (Dec 4, 2010)

yes i have removed all of that pipe all the way to the little piece in fornt of the grill. 
and i have also cut out some of the factory air box. i hope to get some pictures up soon. sorry for the delay guys.


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## Seko (Jan 17, 2011)

I Did this All I get is bad trottle response bad air gas ratio.....

I put a pipe from my old cai i cut and grind a hole for the MAF and put a K&N filter on it result 

Turbo sound 
improved gas mileage

result SRI


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## LARRY01Z28 (Dec 4, 2010)

Seko,
do you have some pics of your sri??


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## turbo6sp (May 10, 2011)

i took the tube right after the airbox off today and i still cant hear a thing, is thier anything eles that can be done besides cutting up the airbox?
thanks jon


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## osiris10012 (Feb 4, 2011)

turbo6sp said:


> i took the tube right after the airbox off today and i still cant hear a thing, is thier anything eles that can be done besides cutting up the airbox?
> thanks jon


if you still have the stock air filter that would be the reason. the stock filter on the cruze may possibly be the most restrictive filter i have ever seen. these guys are running the k&n drop in filter


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## LARRY01Z28 (Dec 4, 2010)

yes add a K&N filter and you may hear more.


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## turbo6sp (May 10, 2011)

osiris10012 said:


> if you still have the stock air filter that would be the reason. the stock filter on the cruze may possibly be the most restrictive filter i have ever seen. these guys are running the k&n drop in filter


Does any one have any sound clips with the k and n in? 
Thanks jon


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## LARRY01Z28 (Dec 4, 2010)

i dont have any way of doing sound clips. if i did i would post them up for everybody


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## turbo6sp (May 10, 2011)

LARRY01Z28 said:


> i dont have any way of doing sound clips. if i did i would post them up for everybody


is it comparible to the injen? sound wise
jon


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## LARRY01Z28 (Dec 4, 2010)

no it is not as loud. but it is free. and it is louder. it cost me 45 bucks for the k&n and some time to cut the box and remove all of the air silencer stuff. 
throttle response is better. fuel economy is not any better or worse. it seems to be the same. it is loud enough for even my wife to notice it when she drove my car after i did it. and she is not a gear head at all.


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## hoyaj (May 20, 2011)

I have removed the first section of black pipe below the airbox. The ECU definitely noticed, and after a few hesitant moments, the car is smooth again and seems much more responsive. I have the K&N on the way -what is up with that stock air filter?

Anyway, what information on that should I pass along to the trifecta folks when ordering the tune?


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## Skilz10179 (Mar 22, 2011)

hoyaj said:


> I have removed the first section of black pipe below the airbox. The ECU definitely noticed, and after a few hesitant moments, the car is smooth again and seems much more responsive. I have the K&N on the way -what is up with that stock air filter?
> 
> Anyway, what information on that should I pass along to the trifecta folks when ordering the tune?


 You shouldn't need to tell them anything seeing how you haven't changed the way air flows across the maf sensor.


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## hoyaj (May 20, 2011)

Ok. Makes sense. For some reason I thought they wanted to know whether the vehicle has switched to a K&N filter, etc. Thanks for the clarification.


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## LARRY01Z28 (Dec 4, 2010)

I say tell your tuner everything youve done to the car. just to be on the safe side.


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## TGreyCruze (Feb 21, 2011)

That is removed on mine and i have no issues. My car with an Injen Intake was put on the dyno and after them adjusting the tubing it ran good A/F. Now im back to stock with that specific tubing removed in the pic above and a high flow filter and it runs fine, now i dont know how that will effect the Trifecta tune i ordered but i emailed Vince just now letting him know.


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## NBrehm (Jun 27, 2011)

vitgia78 said:


> I can easily get 80km/h with 1,600 rpm (2,000 rpm before).
> 
> 
> (Sorry about our language at the picture)


Huh? You must be in a different gear or that little tube bends the laws of physics. Speed and RPM are determined by gear ratio. Is there a valve on the tube (I haven't looked) because it may be PCV in which case you really want to hook that back up. Has anyone identified exactly what the parts you are removing do?

EDIT: Did some research and it does appear to just be a drain tube(#18?)so enjoy the mod!


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## Macman (May 4, 2011)

wow, I'm interested in doing this, if someone would like to help . I'm now thinking of upgrading the air filter at least, thoughts.


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## vitgia78 (Mar 9, 2011)

NBrehm said:


> EDIT: Did some research and it does appear to just be a drain tube(#18?)so enjoy the mod!


Remove 14, 15, 16 is ok


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## TGreyCruze (Feb 21, 2011)

I think the ones removed on mine are entire #9 and 14,15,16.


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## Crewz (Jul 12, 2011)

K&N's SRI instructions states it's a drain tube.


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## sciphi (Aug 26, 2011)

Bump...

In that figure up above, I removed 9 completely. 12 also was taken out. 14 was left in since it's straight into the fenderwell, and isn't any restriction. I haven't driven it yet, so impressions will have to wait for later.


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## LARRY01Z28 (Dec 4, 2010)

i removed most of everything. i even cut the bottom out of 3.


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## sciphi (Aug 26, 2011)

I noticed my intake temperatures were about 6-10 degrees above ambient when driving on the highway, and no change in throttle response with those parts out. It also heatsoaked badly driving around town. I may put those big parts back in, and see what that does to my intake temperatures.


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## CHEVYCRUZE RS (Mar 29, 2011)

i removed everything in the figure a while back lol....around 3k after i installed my intake, i now have 15,600km. The temp. in the intake did change a bit, but nothing crazy. Did a get bit of rough idles but im pretty sure thats my Injen intake.......Vince is gunna fix that up haha! Im coming up with a simple, cheap mod to bring better air flow to the SRI. Possibly through the front right fog light. A plastic, bendable pipe would be perfect to use.....providing the intakes with a bit more air flow. The stock parts IMO, were a bit crazy.....to many bends and so much going on. A smooth pipe would work best, shooting right up to the intake and keep it roughly 4-6 inches away from the actual intake!


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## XtremeRevolution (Jan 19, 2012)

CHEVYCRUZE RS said:


> i removed everything in the figure a while back lol....around 3k after i installed my intake, i now have 15,600km. The temp. in the intake did change a bit, but nothing crazy. Did a get bit of rough idles but im pretty sure thats my Injen intake.......Vince is gunna fix that up haha! Im coming up with a simple, cheap mod to bring better air flow to the SRI. Possibly through the front right fog light. A plastic, bendable pipe would be perfect to use.....providing the intakes with a bit more air flow. The stock parts IMO, were a bit crazy.....to many bends and so much going on. A smooth pipe would work best, shooting right up to the intake and keep it roughly 4-6 inches away from the actual intake!


That will provide very little benefit. A whole lot more work than its worth. Trust me, I've been there. The only way that will be beneficial is if you can seal off the cone filter so that the ONLY air it brings in is the air that's coming from the duct in your fog light. Otherwise, the only benefit you'll see is at higher speeds, and even then the benefit will be minimal. 

The crucial thing here is separating the cone filter from the rest of the engine bay so that you're not pulling hot engine air into the intake. Blowing a little bit of cold air at a SRI (aka warm air intake) is not going to be enough.


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