My modified airbox!... (56k warning!) NOW with log results!...

[Feel]

I've run mine like that on and off - certainly makes more induction noise that way.

Have you got any concerns about sucking in hot air? You know I ran a scoop on mine and I don't remember a significant difference with the scoop and air feed compared to an open airbox (other than noise).

 

[J@mes]

phil... Im not concearned about heat as I instantly felt it pull harder and the logs have backed it up! and its hardly winter anymore so tbh no I am not bothered/worried about heat issues!

 

[drvince]

Don't quite understand ?
What good is it to use 120mm pipe, when the intake to the engine (MAF) is 80mm ???
(effectively even smaller, while the MAF obstructs half the pipe)

Airflow is only as high, as the smallest diameter in the traject will allow to pass.

 

[J@mes]

Don't quite understand ?
What good is it to use 120mm pipe, when the intake to the engine (MAF) is 80mm ???

Airflow is only as high, as the smallest diameter in the traject will allow to pass.

who is using a 120mm pipe?!

having a bigger pipe (80/100mm) going into the air box helps the air flow... the engine is no longer sucking through a straw in comparison!

before and after logs back this up, end of!

 

[drvince]

Topicstarter used a 102mm pipe ,

Nope you're wrong ,
As I said : airflow is only as high, as the smallest diameter in the traject will allow to pass.

In this case the pipe holding the MAF sensor (and even being obstructed by it).

You can add any size of pipe in front of this, no matter how large it is.
But airflow will not exceed the limitation of the smallest opening in the traject.

 

[J@mes]

ok so the VAG COM before and after logs obviously lie!

 

[D.K]

So if it there's no point going bigger than the MAF then why do so many tuners sell great big induction kits

Like J@mes said the logs speak for them self and I can vouch for the effect's of fitting a bigger feed pipe It does work

 

[drvince]

Never mind ,

Basic physics laws don't apply to Seat then )

 

[lc_allan]

Never mind ,

Basic physics laws don't apply to Seat then )

I would guess it's to increase the air flow into the air box.
If the standard one is poor then I'd imagine the 80mm maf will not have a consistant flow.
I'm sure with a bigger feed into the box increasing the airflow then the full 80mm will have a constant flow to use. Just my theory anyway

 

[vwbassett]

Hi, just read most of the post and its great stuff to see what you've done. Just to clarify did you find the best place for the hose to end at just before the headlight to the side of the battery? and where/how much was your hosing?
Cheers
Adam

 

[Avant4me]

Never mind ,

Basic physics laws don't apply to Seat then )

Flow rates are not just governed by the size of the tubing, but also the speed at which the air flows through it. If you can direct enought air into the airbox, you will get a slight pressurisation in the air box which will cause air to flow faster into the MAF.

 

[vwbassett]

To answer the question i asked as to ducting suppliers i recommend www.carbuildersolutions.co.uk as i use them for a lot of the kit car bits just forgot they did the stuff

 

[olliep]

why does the inside of the air box requite smoothing? will the panel not fit without it?

 

[DPJ]

why does the inside of the air box requite smoothing? will the panel not fit without it?

To speed the airflow and therefore enable a greater volume of air through the filter.

 

[jonjay]

Flow rates are not just governed by the size of the tubing, but also the speed at which the air flows through it. If you can direct enought air into the airbox, you will get a slight pressurisation in the air box which will cause air to flow faster into the MAF.

Saved me couple of minutes typing that

Good post.

 

[brad1]

i felt a difference after i finished fitting mine, plus better air feed with colder air so a definate improvement over standard and also j@mes has logs to prove, so drvince, if you have any logs to prove otherwise, please provide us....

 

[DPJ]

Topicstarter used a 102mm pipe ,

Nope you're wrong ,
As I said : airflow is only as high, as the smallest diameter in the traject will allow to pass.

In this case the pipe holding the MAF sensor (and even being obstructed by it).

You can add any size of pipe in front of this, no matter how large it is.
But airflow will not exceed the limitation of the smallest opening in the traject.

But.........
The air is being sucked in by the turbo. The air velocity through smaller diameter pipework will be faster than through larger diameter pipework. The speed of the air through the induction to the turbo will vary on its way. The MAF is not a restriction.....

 

[Ultra_Joel88]

 

[drvince]

Of course it improves when installing cold air induction, I wasn't arguing that.

I was trying to explain that for airflow, enlarging the size of tubing would not matter,
once it exceeds the size of the intake tube / manifold.

Just simply try to visualize it in your mind, by removing everything in front of the MAF (air filter/tubing) ... or even the manifold.

Now THAT HOLE is your airflow.

Then start visualizing holding an enormous tube - 10 miles wide - to that hole.
It doesn't matter, you see ?

As for the original airbox :
Yes, It would make sense to enlarge the intake to the same size of the MAF-tube.
Again, any larger would make no difference.

You are referring to logs, which seem to show the difference with the original airbox

 

[DPJ]

Of course it improves when installing cold air induction, I wasn't arguing that.

I was trying to explain that for airflow, enlarging the size of tubing would not matter,
once it exceeds the size of the intake tube / manifold.

Just simply try to visualize it in your mind, by removing everything in front of the MAF (air filter/tubing) ... or even the manifold.

Now THAT HOLE is your airflow.

Then start visualizing holding an enormous tube - 10 miles wide - to that hole.
It doesn't matter, you see ?

I agree with what you say.
The issue is in making sure there is as little restriction in the pre-maf pipework as possible.
A larger 100mm tube will offer a smoother flow of air than an 80mm tube. I have seen experiments done with varying sizes of pipework, *corrugated and smoothed wall. There is a difference. I agree that above a certain size, there will be no difference. (4" corrugated offered the same airflow at the MAF as 3.5" smooth walled.)