Polo 9n: Intercooler Modification 6L0805639A - Your Opinion

Hello everyone,

I performed a modification of the intercooler piping on a Polo 9n3 with a 1.9 TDI BLT engine.

Instead of the original part, a Seat part with the number 6L0805639A was installed.
This part is the SMIC steering rack from the Ibiza FR/Corboda TDI.
Besides, I cut a slot in the fender to better vent the air that has flowed through the radiator (according to theory), following this guide: http://www.polo9n.info/Wissen/anleitungen/optimierung-der-kuehlluftfuehrung-zum-ladeluftkuehler
Furthermore, the air intake was cut out as much as possible and then re-covered with a racing mesh grille.

The Seat part fits the bumper better than the original part, and it is overall "tighter" against the bumper than the original two-piece air duct.
The holes in the Seat part were closed with fabric tape.

The following values were recorded for measuring devices 7 and 11 on the highway:

Outdoor temperature 28-29°C.
Intake manifold temperature, maximum: 99-109°C (max. 80° above ambient temperature).

A ride from last week with the original air intake and slot in the wheel arch revealed:

Outdoor temperature 24-25°C.
Maximum intake manifold temperature: 94-100°C (max 75° above ambient temperature).

I'd be interested to hear your opinions, as I think that, if there has been any improvement at all, it's only been minimal. However, I haven't noticed any significant deterioration either.

Can I simply compare the two trips with each other?
The conditions are always different when it comes to traffic flow, gas pedal usage, etc.

Are there any data logs or log files from another BLT driver available?
What are your experiences? Please tell us what you think! (Even if you think it's irrelevant...)

Attached are the log files and some pictures of the event.

Hello,

Quote:

Furthermore, I cut a slot in the fender to better vent the air that has flowed through the radiator.

Depending on the specific 9N model and year of manufacture, the air may or may not be able to escape after the catalytic converter. In the worst-case scenario, the wheel arch liner can completely block the airflow after the catalytic converter.
If that is the case, then a conversion makes sense, as the differences in charge air temperature and performance are significant.

If the wheel arch already allows for good airflow of the coolant from the factory, further modifications will only have a minimal impact. Removing any existing fog lights may provide a slight improvement.

I will not analyze your logs because they were created without careful consideration, and therefore their informative value is unfortunately zero. It is not possible to determine the vehicle's speed, fuel injection rates, ambient air pressure, wind conditions, etc. from the logs.

See also:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Rainer,

"So, if I were to install air vents behind my rear license plate on my Octavia 1, would that increase performance or mitigate the power loss when the engine is hot? Because my wheel arch is completely closed off. On the other hand, wouldn't that also let in a lot of water and dirt?"

Octavia_4x4 wrote:

Rainer, That would mean, if I were to install air outlets behind my LLK (low-level air intake) on my Octavia 1, would that give me an increase in performance or mitigate the power loss when it's hot? Because my wheel arch is completely closed.

"Zu" in Polo 9N (not all models) means that there is almost nowhere for air to escape behind the air conditioning unit, everything is sealed. I haven't seen anything like this in any other VAG model before.

Typically, either "vanes" are located inside the fender well, or there is a gap between the fender well and the rearward-extended bumper (spoiler). Alternatively, as is the case with the A6 4F, the cooling air for the intercooler can escape into the engine compartment.

It will not be possible to inject more fuel than the current maximum amount. Therefore, modifying the engine for more power only makes sense if the engine control unit is already reducing the fuel injection amount due to excessively high intake air temperature.

Octavia_4x4 wrote:

On the other hand, it also lets all the water and all the dirt in, right?

Okay, what can I say? I mean, who is so completely stupid to do something like that, causing all this mess?

Best regards, Rainer.

Hello Rainer,

Yes, the wheel arch liner is completely closed on mine!

What would you recommend modifying here, or do you know of a working solution?

In the Polo forum, someone installed the wheel arch liner from an Audi S3. They cut out the section with the mesh grille and then fitted it into the wheel arch liner of a 9N3.

Sure, the speed is missing in the log... I could have figured that out myself. Unfortunately, I've only had VCDS for a few weeks and I'm not very familiar with it yet.

Es würde doch eigentlich auch ein Log im 3. Gang ausreichen welcher von 1500 bis 4000 U/min gemacht wird.... MWB 7 MWB 11 ...

So, I'm going to reattach the original parts to the cooler, and then I'll arrange for an exhaust outlet at the back.

Thank you in advance for your opinions!


EDIT: The Polo is a 9N3 model, manufactured in 2007.

Quote:

What would you recommend modifying here, or do you know of a working solution?

The easiest way is to cut a horizontal slit, 10cm wide and 2cm high, at the very bottom of the fender liner. A carpet knife and a hot air gun can help with this.

Best regards, Rainer.

@mullemaus: You have a private message.

"On my old Golf 4, I had installed an R32 front bumper and modified the airflow for optimal cooling of the intercooler. Furthermore, the area between the intercooler outlet and the wheel arch was completely open, creating a dedicated airflow channel just for the intercooler, which resulted in almost perfect intercooler temperatures for a turbocharger."
"In our 6Y Ibi at the time, the situation was far from ideal. Everything was too cramped at the bottom, and the warm exhaust air from the air conditioning system had to pass between the body and the engine mounting. However, air also flows out from the front, entering the engine compartment through the radiator. This apparently had a negative effect on the air conditioning system's performance."
A small improvement has made cleaning the LLK easier.

@ Rainer:

I didn't plan on cutting it from the top. However, if I cut it from the bottom as you suggest, all the dirt will fly up onto this plastic piece that connects the bumper to the fender well.

Since I ride not only on roads but also off-road, the main consideration is whether it should be done at all.


I'm also considering cleaning the LLK (likely referring to a cooling system), but the disassembly seems like too much hassle. I was therefore thinking about blowing it out with compressed air in the opposite direction of the flow, i.e., from the wheel well towards the front.

@oki

Quote:

All the dirt flies up at me and lands on this plastic strip that connects the bumper to the fender well.

Then, if possible, completely remove it to improve stability.

Before you start tinkering, why not just log the relevant area? Even with my ASZ (vehicle), I don't have any issues. Sure, it could be better, but since I'm just messing around with the car anyway, it would be a waste of effort. Not every measure that makes sense for vehicle A is also good for vehicle B. Very rarely, the people who earn their living designing and developing these vehicles have also made some rudimentary preliminary considerations, even though many of them are certainly not as clever as most people here .

Octavia_4x4 wrote:

@ Rainer: I didn't plan to cut that from the top. However, if I cut it from the bottom as you suggest, all the dirt will fly up onto this plastic piece that connects the bumper to the fender well...

Hello,

Why do you even want to cut anything? Do you actually have the problem that there's no opening for the exhaust air at the intercooler, and the charge air temperature is too high?


Post 06-08-2012 11:18 Title: Intercooler duct for Polo 9n modified to 6L0805639A - your opinion. Replies with quote Edit or delete this post Delete this post Show IP.
"dieselschrauber" wrote the following:
Octavia_4x4 wrote the following:
@ Rainer:

I didn't plan on cutting it from the top. But if I cut it from the bottom, as you suggest, all the dirt will fly up onto this plastic piece that connects the bumper to the fender well.

Hello,

Why do you even want to cut anything? Do you actually have the problem that there's no opening for the exhaust air at the intercooler, and the charge air temperature is too high?

Best regards, Rainer.


"Same here, and if you absolutely want to cut, then follow these instructions:"
http://www.polo9n.info/Wissen/anleitungen/optimierung-der-kuehlluftfuehrung-zum-ladeluftkuehler

The hole must be cut in a way that prevents dirt from falling into the SMIC.

Best regards, Rainer.