centra air box ????

[sinist4]

hey
well heres the problem, in the na there is a centre air box and there are 2 pipes that come out of it and connect to the engine. Does any one know what these pipes do ?

cheers
eD

[matty_et]

theres actually 3 rubber hoses that go onto that air box..i assume your talking about the hoses approx 3/4 inch diameter. theres one next to the throttle body, one on the passenger side of the air box and one hidden under the large air intake pipe. im preety sure at least 2 of them come from rocker covers on each head..i think there like breather hoses and the warm air comeing off the engine also helps start and run the engine when extremely cold...i think

can some one validate this for me? also would it hurt to run these hoses to a catch can instead and plug the hoses on the intake box, so as to not be sucking warm/ oily vapour into the intake?

[sinist4]

heres a pic of the engine bay, i've circled the 3 pipes. Could i just not connect them up to the intake pipe (after market) and put those small breather pods at the end of them instead?




cheers
eD

[matty_et]

that one you circled on the left....thats you main air intake pipe, the pipe that runs from you air filter box the 3rd hose is actually tucked up underneath it kind of (its quite hard to see) its the same size as the other 2 hoses.

i wouldnt disconnect them and replace with filters, this would probably be illegal as it would not meet the emissions regulations, and would leave a mess over you engine in time. if you really want to avoid the oily vapor and hot air getting sucked in you could run a catch can and run the hoses to it.
i dont really know if its worth the hassel though, the gains would be miniscule, if however its better for you engine and intake system..im unsure.

can any one tell me why in the photo above he has a Mass air flow sensor on the pipe coming out if his air filter box and my car doesnt? mines a MY06 2005 2.5i where is my MAF?

[sinist4]

that one you circled on the left....thats you main air intake pipe, the pipe that runs from you air filter box the 3rd hose is actually tucked up underneath it kind of (its quite hard to see)

well yeah i mean was meant to circle the pipe behind the main intake pipe (the pipe that seems to be the same as the one on the right)

Okay this is the problem, i've got an intake pipe and it only has 2 connects for the breathers on it, so which one will i connect?

[matty_et]

ok yeh well when you pull that box out youll see the other hose anyways, but you will have to connect all the hoses that you remove. if your new intake pipe only has 2 spots to connect the hoses to you may have to get a T - piece of some sort to join 2 of the hoses into 1 and then connect to your new intake pipe. where did you get the pipe from i actually wouldnt mind one myself, any photos of it?

[matty_et]

although i do remember when i pulled out that box on my car, where those hoses go onto that box they dont actaully direct the 'blow by gasses' (the oily mist and that that comes through those hoses) straight back into the intake pipe, they sort of circulate around in that box before going into the intake. you'll see when you pull that box out.

so in your case with this new pipe id suggest actually installing a catch can and plug the holes on you new pipe. so as to not feed the blow by gasses directly back into the intake.

[EJ25]

where did you get the pipe from i actually wouldnt mind one myself, any photos of it?

The intake pipe he has is from weapon R, an american brand (i think)

[sinist4]

ok from the link below i;ve worked out that, the 2 pipes on the sides suck in air and the one in the middle blows the air back out. So if i get a small breather filter like the one in the second pic. and connect the centre one to the main filter pipe. i should be rite yea?

[sinist4]

ok so can i just add a catch can or ? to connect to those pipes.

[matty_et]

ok...im kinda confusing myself here the hose that goes to the centre of the air box (next to the throttle body connection) is from the crank case PCV valve, this valve should be open when the engine is running and vaccum is obtained but closes in the event of a backfire etc. to prevent the back flow of air pressurising the crank case (its preety much a one way valve) so yes you will need to connect that hose to your new main intake pipe. as for the other 2 hoses that come from either head, you could get a T- piece to make the 2 hoses into one then run it to the other spot on you new intake pipe, or get one of those little filters your talking about and do it that way, but i think over time it will leave a mess in your engine bay, even though those hoses do a lot more of breathing air in, i think it is possible that oil could splutter its way through the filter in time, i think a catch can would be a much neater option. send some pics when your done

[overl0ad]

if you leave them off, like i did by accident (honest, it was an accident) they car threw up a code. (flashing cruise light on the NA)

you can just use a T joint to connect them back to your intake.


edit: when they were off, i noticed the smell of exhaust in the cabin at low speeds (under 50kmh)

and it is illigal to vent to atmosphere. if you plumb back, then it's all good.

if you have an aftermarket intake kit, then i suggest that you run an oil catch can as the orginal box in the facelifted NAs do have catch area of sorts.

[sinist4]

if you leave them off, like i did by accident (honest, it was an accident) they car threw up a code. (flashing cruise light on the NA)

you can just use a T joint to connect them back to your intake.


edit: when they were off, i noticed the smell of exhaust in the cabin at low speeds (under 50kmh)

and it is illigal to vent to atmosphere. if you plumb back, then it's all good.

if you have an aftermarket intake kit, then i suggest that you run an oil catch can as the orginal box in the facelifted NAs do have catch area of sorts.

so if i got something like this (pic below) i would connect the centre pipe to the one on the bottom and the other 2 to the ones on top ?

[sinist4]

I only have 1 connector on the intake, could i connect all 3 to the same connector?

or am i wasting my time and should just forget about it?

[matty_et]

hey again, i would double check maybe with someone like PHAT GT as he seems to know his stuff preety well, but ithink you could get any type of catch can weather its got 3 connections or 2.

in the case of having 3 connections i would run the hose from the PCV to the catch can the run another from the catch can back to the air intake pipe, then join the 2 from each rocker cover into one with a T-piece and run that to the left over spot on the catch can.

in the case of only having a 2 connection catch can run the hose from the PCV directly to the intake pipe and then run both hoses from the rocker covers to the catch can.

im preety sure you need to keep vacuum on the PCV hose so hense looping it back to the intake pipe with the 3 connection catch can, and with the 2 connection...just connecting it to the intake pipe directly.

but yeh double check this with some whoes a little more confident than myself.

also i dont want to dissapoint you here as i may be wrong (again) if it is a Weapon R type intake pipe, from the photos i see on their site the pipe and pod filter sit closer up to the strut tower and not down near the head light, i would imagine all you would achive is sucking in the hot under bonnet air and your car would probably run no better possibly even worse than with the stock air box/ cold air intake set up. i think a hks air filter and air intake guide would probably serve us N/A guys best