2.0 TDI Cold Air Intake - Is this any good?

[Pearce]

Also, You'll have to excuse me questioning removing the MAF grid and getting rid of the turns. I have read on a post that the MAF grid can reduce airflow by 22% and that because you get rid of the bends the air is less turbulent, that warrants getting rid of the MAF grid. which is used to calm the airflow.

[Greg Roles]

Not so Manol, the stock TDI / Sportline etc Golf Airbox intake has a pretty twisted intake path, that APR intake is dead straight in comparison, but yes, the flow through the stock system is good enough for normal tunes on a TDI. You will note the GTI / R has a similar to that APR box straight intake path in comparison.

[lhennessy]

2.0 TDI Cold Air Intake - Is this any good?

^ manol I don't know if you have actually looked at the stock intake... Lots and lots of twists and turns as Greg said.

Even just the top there is a 90 degree turn...

And don't get me wrong it doesn't make any power difference, just gives a nice dose/flutter and I found that it feels a touch more responsive but other no power gains or anything...


Pearce if you want to organise a time and location I can simply take your for a drive so you can see.

[Mysticality]

You can here the intake in this vid I took.
Skoda Octavia vRS TDI 3" Catback Exhaust Note - YouTube

The stock intake is a maze.





It literally goes straight into a 90^ angle, does a loop-de-loop, then through the filter, around another 90^ angle, through the MAF and into the turbo!

[team_v]

You can here the intake in this vid I took.
Skoda Octavia vRS TDI 3" Catback Exhaust Note - YouTube

The stock intake is a maze.





It literally goes straight into a 90^ angle, does a loop-de-loop, then through the filter, around another 90^ angle, through the MAF and into the turbo!

It may just be on the TSI engine but there is also a big gap under the "ram" part which i was advised is to let leaves/dust fall out of however it also allows warm air from the engine bay directly into the intake system.

[Greg Roles]

It's for water ingress, and if ever all the stock Golf intakes needed a rubber flap hinged at the top to suck shut, well that's the biggest flaw of them. It does help prevent you hydro locking your car, but boy you'd have to basically drive into a river, no chance of rain etc doing that.

[team_v]

It's for water ingress, and if ever all the stock Golf intakes needed a rubber flap hinged at the top to suck shut, well that's the biggest flaw of them. It does help prevent you hydro locking your car, but boy you'd have to basically drive into a river, no chance of rain etc doing that.

Well that is a better explanation that the guesswork i have read.
Either way, it is a big gap that is remedied by alternative intake systems.

[Dr freedom]

Amazing when you take the lids of both stock & the Carbonio CAI's the difference. Ones bent like a bowel, ones straight. I guess when you wear blinkers youll never see it.
Surely though Greg, it needs what every CAI needs to get the full benefit, tuning.

[Guy_H]

We don't import the Carbonio for the TDI into Australia.

We imported 10 of them, and had to refund 9 people. They give uneven running, hesitations and a misfire like condition, particularly on tuned vehicles.

It does not show up on US spec engines, but obviously on the ROW spec cars it is an issue - we were not the only country to report it & it has been withdrawn from sale in several countries.

We have also seen this issue with several other brands of intake (straight through design). It seems the MAF signal cannot be properly processed with too much air flow (velocity).

[gldgti]

The MAF needs the airlfow to be quite parallel to the pipe direction to read properly. The standard airbox including the grid pre-maf are really designed well to provide this 'quazy' laminar flow (I wont say its actually laminar because that very hard to achieve at high velocities in a pipe).

All the aftermarket designs 'look' better, but I would rather compare dyno plots for an assessment of that. Despite appearances, the stock airbox is very good. People often like to forget that inside the airbox is a filter cartridge, and when you factor that into the flow pattern and think about pressure regions, you can understand that the factory setup is not poorly designed at all - in fact is very well designed.

All I;ve done on mine is put some gaffer tape over the back opening of the scoop to raise the dynamic pressure in the airbox rather than wasting the ram air effect - but I do find a lot more bugs in the air box now because of it. I guess if you are willing to clean it out periodically it doesn't matter.

[MountainBikeMike]

The MAF needs the airlfow to be quite parallel to the pipe direction to read properly. The standard airbox including the grid pre-maf are really designed well to provide this 'quazy' laminar flow (I wont say its actually laminar because that very hard to achieve at high velocities in a pipe).

All the aftermarket designs 'look' better, but I would rather compare dyno plots for an assessment of that. Despite appearances, the stock airbox is very good. People often like to forget that inside the airbox is a filter cartridge, and when you factor that into the flow pattern and think about pressure regions, you can understand that the factory setup is not poorly designed at all - in fact is very well designed.

All I;ve done on mine is put some gaffer tape over the back opening of the scoop to raise the dynamic pressure in the airbox rather than wasting the ram air effect - but I do find a lot more bugs in the air box now because of it. I guess if you are willing to clean it out periodically it doesn't matter.

THIS

10char

[manol]

The MAF needs the airlfow to be quite parallel to the pipe direction to read properly. The standard airbox including the grid pre-maf are really designed well to provide this 'quazy' laminar flow (I wont say its actually laminar because that very hard to achieve at high velocities in a pipe).

All the aftermarket designs 'look' better, but I would rather compare dyno plots for an assessment of that. Despite appearances, the stock airbox is very good. People often like to forget that inside the airbox is a filter cartridge, and when you factor that into the flow pattern and think about pressure regions, you can understand that the factory setup is not poorly designed at all - in fact is very well designed.

All I;ve done on mine is put some gaffer tape over the back opening of the scoop to raise the dynamic pressure in the airbox rather than wasting the ram air effect - but I do find a lot more bugs in the air box now because of it. I guess if you are willing to clean it out periodically it doesn't matter.

****ing, exactly.
You are only throwing away $$$ buying aftermarket CAIs for a stock engined TDI.

[Mysticality]

****ing, exactly.
You are only throwing away $$$ buying aftermarket CAIs for a stock engined TDI.

Unless you want the sound, of course... Which is a huge change from stock.

[vk]

Unless you want the sound, of course... Which is a huge change from stock.

This ^^

I want to get an intake for my GT TDI purely to have a nice sound.

Looking through this thread everyone seems to have their own preference.

Which one creates a flutter ? (I didnt think this was possible with diesel)
and which one has the best intake noise?

I noticed someone mentioned the BMC but doesn't that require custom mounts etc to have it installed on a TDI?

And which is the easiest to install/remove?

[moda]

The MAF needs the airlfow to be quite parallel to the pipe direction to read properly. The standard airbox including the grid pre-maf are really designed well to provide this 'quazy' laminar flow (I wont say its actually laminar because that very hard to achieve at high velocities in a pipe).

All the aftermarket designs 'look' better, but I would rather compare dyno plots for an assessment of that. Despite appearances, the stock airbox is very good. People often like to forget that inside the airbox is a filter cartridge, and when you factor that into the flow pattern and think about pressure regions, you can understand that the factory setup is not poorly designed at all - in fact is very well designed.

All I;ve done on mine is put some gaffer tape over the back opening of the scoop to raise the dynamic pressure in the airbox rather than wasting the ram air effect - but I do find a lot more bugs in the air box now because of it. I guess if you are willing to clean it out periodically it doesn't matter.

Super cool to see to see stuff that i'm currently doing at uni (mech engg - final year fluid mechanics) actually being used and talked about on enthusiast forums Makes me feel like my degree isn't a waste of time heh.