LLK die 10te: Größen und Leistungsstufen | Posts 96+

Hi,

I would first remove the red paint and then measure again.

Best regards, Rainer.

Cosi wrote:

During my measurements back then, it was completely rectangularly cut out.

Yes, I understood it that way too.
However, if the logs indicate that an estimated doubling of the "effective flow area" (achieved through more slits and lamellae twisted further towards an "open" position) results in no reduction in the lower limit temperature (LLT), then I suspect that a rectangular hole would not offer any further improvement either.
The image, by the way, shows the enlarged gill filaments, which is what they look like "afterward."


How did you protect the back of the LLK (likely referring to a specific type of agricultural equipment) from getting dirty with debris kicked up by the tires back then?

Because while a low LLT (Lowest Load Tire pressure) is nice, if it ends up being higher than it was without the hole in the fender well after the next wet drive due to mud accumulating on the back of the tire, then I'd rather just do without the hole...

Quote:

I admire, just like you, Rainer, and some others here, how you try, test, and also document such things.

Thank you - we think that it might be useful to someone else at some point.
And in my case, there are also interesting and insightful comments that I can use.

Rainer K wrote:

I would first remove the red paint and then measure again.

Well, the layer of paint on the lamellae is quite thin, and as far as I can tell, it doesn't really penetrate deep into the mesh.

I've already washed the color off the connection points using a thinner, and the layer is peeling off in curls.
If I put that in the fins, the resulting wrinkles (which I can't remove from the mesh) might actually reduce airflow more than the bare metal improves heat transfer...

Hello.

@ulf

It's just a thin, black mesh. It's mainly there to prevent things like stones from hitting it. You shouldn't be too skeptical about it. After all, the openings are also facing downwards, so small stones could potentially get in.



Best regards, Cosi.

Cosi wrote:

After all, the openings are also directed downwards, and that's how small stones could fly in.

. . . but only when reversing .

Ultimately, the dirt (almost) flies tangentially away from the tire and hits my lamellae at a right angle during forward motion, while a grid behind the tire (for this direction of ejection) would generally be permeable.

ulf wrote:

Cosi wrote: After all, the openings are also directed downwards, and that's how small stones could fly in. . . . but only when reversing . Finally, the dirt (approximately) flies tangentially away from the tire and hits my lamellae at a transverse angle during forward motion, while a grid behind the LLK (for this direction of throw) would generally be permeable.

Hello.

Sure, that's true. However, we didn't experience any problems with stone chips or anything else on several vehicles. But, as I said, you shouldn't be too skeptical. Even at the front, which is the most vulnerable spot on the car, is the opening to the coolers. Stones fly around wildly there, kicked up by the vehicle in front. And even then, nothing really happens.


Best regards, Cosi.

Cosi wrote:

We had several vehicles, but we didn't experience any problems with stone chips or anything else.

Among them, there definitely wasn't a Polo 9N .

But seriously, once again:
Looking at the light gray-brown layer of dirt inside the wheel wells, and then imagining that the corresponding splash of mud is sprayed from behind into the radiator fins with every rainy drive, I suspect that soon they will only have a fraction of the normal free flow area -> reduced airflow -> increasing engine temperature.

"My car's wheel wells are incredibly dirty, but the front of the car isn't nearly as bad, so the stock intercooler's fins are still relatively clear and not blocked."

Next, I will work on creating the smoothest and straightest possible airflow on the front of the SMIC, between the spoiler grille and the SMIC itself, in order to channel the valuable kinetic energy of the oncoming air to the cooling fins with as few turbulence losses as possible.

Quote:

Even at the very front, the most unfavorable location on the car, is the opening to the coolers. Stones fly around wildly there, being kicked up by the vehicle in front.

... nothing really happens. } ... except for a few small dents in the fins, which can be more or less straightened out again with the tip of a pocket knife or something similar.

Hello Ulf,

How about a direct injection system for the LLK, like the one used in the Subaru Impreza?
More or less for occasional overboosting?

Regarding airflow: Ideally, the airflow should not escape from the front of the LLK (Liquid Cooling System). Air always takes the path of least resistance, and that path is around the LLK. This means it would be best if the LLK were located at the end of a 'tunnel.' It's also important to ensure that all possible gaps between the airflow tunnel and the LLK are well-sealed. Only then will the LLK grid be optimally cooled.

Best regards, Rodion.

rodNeX wrote:

How about an intercooler system for the LLK, like the one on the Subaru Impreza? More or less for occasional overboost?

No, thank you, it's not really my thing (it's a matter of taste).

Quote:

It is important to ensure that all possible openings between the ventilation tunnel and the LLK (Low-Level Cooling) system are well sealed. Only then can the LLK grid be optimally ventilated.

I know, and I've taken that into consideration.

Mal eine andere Frage im Zusammenhang mit dem FA über die Verbesserung der Kühlluftversorgung des LLK (2. Thurry to https://community.dieselschrauber.org/en/viewtopic.php?t=6593):
What fraction of the vehicle's speed is the airflow approximately reduced to when passing through a low-clearance area?

If I roughly estimate the cooling capacity of my large SMIC in relation to the maximally conceivable airflow (i.e., with an air velocity of approximately 200 km/h through the fin cross-section of the liquid cooling system), the cooling air would, on average, only need to be heated by about 10 K to absorb all the waste heat of the liquid cooling system.

Conversely, assuming a cooling air stream temperature increase up to the Lower Limit Temperature (approximately 40 K above ambient), a flow velocity of 50 km/h (instead of 200 km/h) would be sufficient to remove all waste heat at maximum power output.

Of course, the truth likely lies somewhere in between, and the cooling air might even be heated to a temperature higher than the stated 40K (the "LLT at half the distance through the LLK" is likely to be about 90K above ambient temperature).
... but for a general understanding of the processes, I would like to know, as a rule of thumb, whether the difference between the theoretically calculable and the actual cooling capacity of a SMIC (Surface Mounted Intercooler) with internal turbulators is more likely to be...
-> due to a low airflow of cooling air compared to the incoming air.
-> due to a significant temperature difference between the air used for charging and the air used for cooling.
results.

Sure, here is the translation of the text from German to English:

"Addendum:"
In practice, this answer would be interesting when revising cooling air ducts.
With low-pressure flow (i.e., low back pressure in front of the air-to-water heat exchanger), one should focus more on aerodynamic air ducts and large cross-sections leading up to the heat exchanger.
In the event of significant back pressure before the LLK (and a lower flow rate), the primary focus should be on sealing any gaps and holes between the air inlet and the LLK.

Hello Ulf,

I have been following your renovation project with great interest.

Ich denke auch, dass der Lack weg muss. This could be...
It can definitely also be removed with "gentle" methods, if you...
The dilution is too delicate.

Since I haven't done anything like this before, I think it would be best to test it on an old...
offer a potentially defective radiator to avoid using the new SMIC as a test subject.
to abuse.

Besides that, I don't understand why anyone would even think of painting a large language model. In my opinion, it makes as much sense as an internal crankcase lighting system.

Here's the translation:

"This also raises the question for me: does it actually make sense to buy a beautiful, shiny, polished LLK (likely referring to a type of metal or component)? Wouldn't it be better if the outer surface of the LLK was also..."
is rather rough?

Regarding the "gill issue," I can imagine using a very fine mesh grid, but even then, it's only a matter of time before it gets clogged with dirt.
Another option would be a fan behind the liquid cooling system (LCS), similar to how it's implemented in the Smart. Unfortunately, you don't have much space back there, so you'd need something "thin," like a Spal fan. Of course, thin fans are more expensive, so the question is, is the effort worth it?

Best regards,
Thomas.

Thomas wrote:

Besides that, I don't understand why anyone would even think of painting a large language model. In my opinion, it makes as much sense as an internal crankcase lighting system.

Well, the radiator manufacturer said: as a corrosion protection .
And because he found the SMIC itself so g***, he chose red as the color .

However, it's unlikely that any paint would have reached the innermost 8 cm (out of a total depth of 11 cm) of the mesh, since it wasn't a full immersion coating.

Since the benefits of https://community.dieselschrauber.org/en/viewtopic.php?t=9868 could not be definitively determined, I would have...

ulf wrote:

eine andere Frage im Zusammenhang mit der Kühlluftversorgung des LLK (2. Part in https://community.dieselschrauber.org/en/viewtopic.php?t=6593):

Okay, my engine (ALH) should handle thermal tuning better than, for example, an ASZ, since I have the same intercooler as the 110/115 HP models...

Roger wrote:

LLK 1J0 145 803 F AHF, ALH, AGR, AJM, AUY, ATD, ASV 1J0 145 803 E ASZ 1J0 145 803 H ARL

Rainer mentioned that with some models, no further improvements can be achieved, so I'm wondering how sensible an LLK upgrade actually is, considering the following disadvantages ->

Roger wrote:

The larger the LLK, the greater the volume that the turbocharger must fill before the engine experiences boost pressure.

dj1 wrote:

I recently had a second LLK implanted in my AFN. The renovation took a while, and then I went on vacation. After the first test drive, it almost seemed like it had less power than before!

What is the approximate performance loss without any tuning, and is an LLK (Low Tension Coil) upgrade registration-free?

Thank you .

fulda wrote:

My engine (ALH) should handle thermal tuning better than, for example, an ASZ, because I have the same intercooler as the 110/115 HP models... 1J0 145 803 F AHF, ALH, AGR, AJM, AUY, ATD, ASV

Yes, your LLK (likely referring to a specific engine type) certainly has a few more reserves thanks to the VAG parts bin than the more powerful TDIs with SMIC (likely referring to a specific turbocharger).

Quote:

Rainer mentioned that with some models, no further improvements can be achieved, so I'm wondering how sensible a LLK upgrade actually is, considering the following disadvantages: The larger the LLK, the greater the volume that the charger must fill before the engine experiences pressure.

It depends on which part of the total volume between the compressor and the intake valves (i.e., including all pipe sections) is increasing.
For engines with long manifolds, such as those found in the Golf 3 or Ibiza 6K TDI, doubling the SMIC volume would have less of an impact on responsiveness and emissions compared to engines with shorter manifolds, like those in the Golf 4 / Ibiza 6L (assuming the same standard SMIC size).
If you only optimize the cooling air side of an existing liquid cooling system, then these disadvantages do not occur .

Benefits of an intercooler upgrade: improved thermal management for the turbocharger and engine, increased air mass flow = less soot or more tuning potential, see also relevant articles.

Rainer K. wrote:

Quote: Regarding Rainer's report, I can only say that the holes don't really achieve much because they are simply too small. Nonsense, just look at the actual size of the TDI LLK area and how much has been cut out. I simply see that with the A3, the ventilation is already so good that there's nothing more to improve.

With other models, things might be different. }
Hi Rainer,

I just noticed while looking at an ASZ-G4 unit that the SMIC (Secondary Mixing Inlet Chamber) is completely open at the bottom, meaning that the warm exhaust air can be directly drawn out from behind the filter downwards.
The exhaust air, flowing directly from the cooler, initially hits the plastic wheel arch liner. However, if a sufficient vacuum is actually created beneath the SMIC (Secondary Air Mass Injector), the air will likely still be able to curve downwards.

Does your A3 look the same?

On the Polo 9N, the SMIC (Secondary Air Mass Injector) is completely encased in plastic from below, and the exhaust air must flow past the engine to the end of the lower engine cover (unless you cut slots/holes in the wheel arch liner).

I'm going to cut a wide opening directly downwards for the exhaust air, right in front of the fan... let's see what that does.

Rainer K. wrote:

Hi, I would first remove the red paint and then measure again.

*dusting*

Okay, I've removed the red dye using a stain remover, and I cleaned the cooling mesh with a pressure washer to get rid of any remaining dye residue (the light shines through perfectly now, and there are no more visible particles).

And lo, the pendulum-mounted LLT log values in the approaching Vmax range are approximately 40 K above ambient temperature, just as they were before .

Strange...

Okay: The ventilation openings directed towards the wheel arch already provided a few degrees Celsius of cooling before the paint was removed.