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Hi guys.
Tomorrow evening i'm going to modify my std airbox as seen in multiple topics on Audizine & Audiworld.
They say to cut a hole in the bottom of the box (approx 10cm diameter), and then re-install it.


My thought is:

- If i cut a hole in the bottom of the box, the air will have TWO different flow directions: One coming from the front of the car (from the std air-duct), and one coming from the hole i made.
Will it be a problem?
I mean, i can't really imagine how much air a 2,7 litres supercharged engine sucks....but i'd suppose it's a huge quantity, and in my opinion two air flow directions would create a big turbolence inside the airbox.

What do you think about it?


Thanks,

Andrea

?
but a mate of mine has done it as well, makes quite a difference apparently.

Thanks for your prompt reply.

Ps. sorry for my english

Just done mine, although found that the front triangle had already been cut out, decided to drill various holes in the box that kind of sit above the wing, to be honest not entirely sure if there is any difference or even if it has lost power.

anyone got a pic of where the cut out should be? I'm all for cheap little mods that raise a smile.

I'd question what performance improvements cutting the airbox will give you - apart from the throatier intake noise of course. There is a vacuum hose going to the bottom of the airbox - I presume this is for the carbon canister / petrol tank breather but can anyone confirm it's purpose?
It's that age old debate over using Cone filters, CAI (Cold Air Intakes) and the factory setup - unless proven otherwise on the rolling road with suitable cooling if it ain't broke don't fix it....

This mod is for S4 airboxes, the RS4 airbox already draws in additional air from a secondary pipe, so I would question the value of doing it on your RS4 airbox.

Nige_RS4

Are there details of this mod for S4's on the site?

To be honest just remove it and drill a load of holes in the base of it, you'll see where the air feed is from the front wing, so in that area really.

Nige_RS4

Are there details of this mod for S4's on the site?

Look in my gallery - photo of the Sportec airbox for the S4 - tells you all you need to know.

S'cuse my complete ignorance of such things but.....I thought that forced induction (turbocharged) airboxes had to be completely airtight, in order to be able to create and maintain a certain airflow pressure [to literally RAM as much air in using the turbo's to create a higher pressure in the box, therefore a higher volume of air into the chambers]?

Surely perforating the airbox compromises this??

doesnt spray from the wheelarch get into the airbox doing this mod?

doesnt spray from the wheelarch get into the airbox doing this mod?

no, not at all, had it on my S4 for 3+ years. Supposedly adds 5 g/s on an S4.

blackb1ade wrote:S'cuse my complete ignorance of such things but.....I thought that forced induction (turbocharged) airboxes had to be completely airtight,

Id have t agree!! this is wot i think, yeah it may sound better on the induction note as you have a hole in your air box also it may mess with the maf as the capacity ov air goin though it maybe different from wot it is supposed to be 'more/less' i dont know! but if you start messing with air flow you may have to get it dynod to sort the fueling out ! as you probably know turbos spool off the exzort gases created from the bang caused in the engine from the fuel and AIR. all im tryin t say is if u piss about the the air as a cheap bhp gain u may still have to spend on set up or you may not i dont know.....

I have read about people cutting a hole then running a pipe from the bumper vent into the new airbox hole. These people also smoothed all the inside of the airbox.