drilled air box?

[Wak-VAGCHECK]

I think this just reflects various opinions and experiences and all are valid to a degree.

What works for one may not work for another , whats deemed a good measurement for one may not be for another.

We tried to test on real road conditions, a number of runs with proper real road airflow.

Rolling road would be great but open bonnet runs wouldnt reflect the same conditions as on road and difficulty with getting proper airflow would have melted a car after 25 odd runs testing all the setups we did.

I agree initial pickup after a stationary period could be effected by some hot air but when you are motoring, the turbo will have drawn through more than enought to be taking all frontal airflow coming into the bay so where you have seen powerloss may be due to the S3 design over the TT's and R32 allbeit they are similar cars.

Our 225 TT consitantly gets 290+ bhp on rollers which is not far short of a k04's theoretical max, running a neuspeed Pflow(and obviously its other mods)

Vagcom is a tool and air mass flow is a direct airflow sensor measurement, not really a guess at all it may not be considered a measurement for power but it is a direct measure of flow and we used that as our measurement for differences of each induction setup.

As you can see there are so many variables in testing, on road, rolling road, real airflow, simulated airflow, Why did Audi not do it, Why do BTCC not do it, why do Neuspeed / K&N sell kits... etc etc...

Sealed cold air feed..... Food for thought....
This was suggested to me , take a straw suck through it, make the straw longer, suck through it... it will be harder.

potentially a seal cold air feed will cause an initial pickup lag as you havent started moving and the turbo is having to suck harder as you have extended the "straw" to the turbo.

Also sealed frontal cold air feed may be a recipe for disaster if there is nothing to diffuse any water ingestion, All the Audi designs I've seen attempt to diffuse flow to allow water to drop from what I have seen.

There are so many opinions to factor in and consider this debate will be a hard one to conclude.

Stick to what you know and what you feel to be correct is all you can do!

 

[666markyboy]

Sealed cold air feed..... Food for thought....
This was suggested to me , take a straw suck through it, make the straw longer, suck through it... it will be harder.

potentially a seal cold air feed will cause an initial pickup lag as you havent started moving and the turbo is having to suck harder as you have extended the "straw" to the turbo.

But what if you increase the Dia of the so said Straw ? fatter straw maybe longer than standard but just as easy to suck through ,this is where ram pipes come into effect on normally asperated engines... gonna be looking at a cold air feed mod very soon

 

[danotto]

i have a green cotton cone filter on my s3,and it sounds superb not very loud a bit of a deeper reving sound at low revs,but basically i want to get a cold air feed to it,ive seen wak tts attempt and it looks long winded,is the original air feed for the standard air box good enough if i refitted that and directed air to the cone filter via ally flexi air feed pipe.or am i just being lazy? would this be worth doing for now ?

 

[Ess_Three]

But what if you increase the Dia of the so said Straw ? fatter straw maybe longer than standard but just as easy to suck through ,this is where ram pipes come into effect on normally asperated engines... gonna be looking at a cold air feed mod very soon

To be fair, rampipes only change the tuned length of the inlet tract of an engine and move the peaks about by messing with pulsing etc...the dimension that matters is not only rempipe tip to throttle plate, but also throttle plate to inlet valve...

On a 1.8T changing the length of the inlet to the airbox isn't really going to do much, as the length from the airbox inlet, through turbo, pipework, manifold to inlet valve remains the same....and with charge pressure involved, engines behave differently anyway.

But, something to consider:
If you want to duct a cold air feed into an airbox and have a sealed set up, you need to consider a few things:
The inlet needs to be large enough not to restrict - a point Wak was making.
It needs to be in a place where it won't pick up too much direct water flow from rain/puddles etc
It needs to be in a cold area...
Ideally, it wants to be at the point where the front bumper skid aerodynamics provide the biggest area of high pressure - relative to the other areas - in order to 'ram' the air in.

Also, using a ribbed hose will slightly reduce laminar flow (but in a big duct...it seems to have little effect as the air speed is low anyway) but will use the ribs and non-laminar flow to drop out water droplets from the air passing through.

So...where to put a cold air duct on an S3?

Behind where the folglights are, at the intakes for the standard ICs is the place where maximum cold air can be found easily, and also the area where a manometer shows the highest pressure (OK...only a few "wg, but pressure regardless).
If you have a FMIC, it's easy...there is no IC or pipework in the way...use the passenger side opening.

So, 4" ribbed duct with a 4" Subwoofer port on the end smoothes airflow from the Passenger side IC intake, just behind the Foglight, and ducts it to the standard, sealed airbox.
The 'subwoofer' port should be positioned pointing directly downwards to avoid direct water entry...
Pass the hose round the side of the battery tray and silicone into the airbox.



Feel free to repeat all the measurements with a manometer...but that's where I found the best source of cold, 'pressurised' air.

In my mind, a proper cold air feed, from a relatively high pressure source fed to a heat unsulating airbox by a non restrictive hose, is a better option than an open filter/drilled airbox sucking in hot air.

I never noticed any increase in flow accross the MAF with my set up...
But on the road, I've not come accross another S3 that felt as strong.

You pays yer money and makes yer choice...

 

[Nilz]

On my Mk2 Golf GTI, i had a huge cossie Pipercross cone filter and believe me it roared like a beast matched with my Magnex 6x4 exhaust, but then on my Mk3 Golf gti i used a jetex panel filter in the standard airbox that had been drilled on the side, again i got the huge roar, but it seems so much more responsive.

However on the S3, i really dont think its worth changing the original setup unless you go down the route of the BMC, which is costly and to be honest, i dont know how it performs....

Nowadays i prefer to keep the noise down to a minimum, rather just have it as stealth as possible....

 

[danotto]

i have the original intercooler set-up,so where would be best for the air feed where does the bmc cda's air feed go on a car with the twin intercooler set-up,cheers guys

 

[Ess_Three]

From memory, there is little space for a feed, with standard ICs...
Can you get it into the area between the inner wing and outer wing, where the standard airbox gets its feed from?
I can't remember...

 

[danotto]

not sure mate,ill have to have a look,there is a hole on the inner wing,where the original feed was but im not sure if it will give me sufficient air flow through a flexi tube to my filter.