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 a more "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 shows the enlarged gill filaments, which are what you see in the "after" picture.


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

Because while a low water level is nice, if it ends up being higher after the next wet drive because of mud accumulating on the back of the grill, then I'd rather just do without the hole in the fender well...

Quote:

I admire how you, Rainer, and some others here 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; the layer is peeling off in curls.
If I put that into 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, which means 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 flies away from the tire at an almost tangential angle and hits my lamellae perpendicularly when moving forward, while a grid behind the tread (for this direction of ejection) would essentially 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 flies (approximately) tangentially away from the tire and hits my lamellae at a transverse angle during forward motion, while a grid behind the front wheel well (for this direction of throw) would generally be permeable.

Hello.

Sure, that's true to some extent. 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 arguably the most vulnerable spot on the car, there's an opening to the coolers. Stones fly around wildly there, kicked up by the vehicle in front. And surprisingly, 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, again:
Looking at the light gray-brown layer of dirt inside the wheel wells and then imagining that a similar spray of mud is being blasted from behind into the radiator fins with every rainy drive, I can only conclude that soon they will be blocked to such an extent that only fractions of the normal free flow area remain -> 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 path on the front of the SMIC, between the spoiler grille and the SMIC itself. This is to ensure that the valuable kinetic energy from the oncoming air reaches 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 somewhat straightened out again with the tip of a pocket knife or something similar.

Hello Ulf,

How about a direct injection system for the liquid coolant, similar to what's used in the Subaru Impreza?
More or less for occasional overboosting?

Und bezüglich der Luftführung: Optimal wäre es, wenn der Fahrtwind nicht von der LLK Front entweichen kann. Denn die Luft sucht sich immer den leichtesten Weg und der ist um den LLK rum. Das bedeutet, es wäre am Besten, wenn der LLK am Ende eines 'Tunnels' wäre. Dabei sollte man auch darauf achten, dass alle möglichen Spalte ziwschen dem luftführendem Tunnel und dem LLK möglichst gut abgedichtet sind. Nur Then, an optimal flow of coolant liquid through the heat exchanger grid is achieved.

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 overboosting?

No, thank you, it's not really my thing (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 optimal airflow through the LLK grid be achieved.

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

[Translating...]

Mal eine andere Frage im Zusammenhang mit dem FA über die Verbesserung der Kühlluftversorgung des LLK (2. Teil in https://community.dieselschrauber.org/en/viewtopic.php?t=6593):
Auf welchen Bruchteil der Fahrgeschwindigkeit wird eigentlich der Fahrtwind beim Durchströmen eines LLK ungefähr runtergebremst?

Wenn ich überschlägig die Kühlleistung meines großen SMIC im Relation zum maximal denkbaren Kühlluftstrom (also mit ca. 200 km/h durch den Lamellenquerschnitt des LLK) betrachte, müßte die Kühlluft im Mittel nur um ca. 10 K erwärmt werden, um die gesamte Abwärme des LLK aufzunehmen.

Umgekehrt ergibt sich bei angenommener Erwärmung des Kühlluftstromes bis auf die LLT (ca. 40 K über Umgebung), daß eine Strömungsgeschwindigkeit um 50 km/h (statt 200 km/h) ausreicht, um alle Abwärme bei Pmax abzuführen.

Natürlich wird die Wahrheit irgendwo dazwischen liegen, und die Kühlluft könnte womöglich auch weiter erhitzt werden als besagte 40K (die LLT "auf halber Strecke durch den LLK" dürfte etwa um 90K über Umgebung liegen) . . .
. . . aber ich würde zum groben Verständnis der Abläufe gerne als Daumenregel wissen, ob die Differenz aus rechnerisch denkbarer und realer Kühlleistung eines SMIC mit inneren Turbulatoren nun eher
-> aus einem niedrigen Kühlluftdurchsatz gegenüber der Anströmung oder
-> aus einer großen verbleibenden Temperaturdifferenz zwischen Lade- und Kühlluft
resultiert.

Nachtrag:
In der Praxis wäre die Antwort interessant bei der Überarbeitung von Kühlluftführungen:
Bei wenig gebremster Strömung (also geringem Stau-Überdruck vor dem LLK) müßte man eher auf strömungsgünstige Luftführungen und große Querschnitte bis zum LLK achten,
bei starkem Stau vor dem LLK (und geringerem Volumenstrom) wären primär Spalte und Löcher zwischen Lufteintritt und LLK abzudichten.

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, 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 engine bay 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 liquid-cooled engine. In my opinion, it makes as much sense as an interior crankcase lighting system.

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

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

[Translating...]

Da der Nutzen der Saugrohrentdrosselung ( https://community.dieselschrauber.org/en/viewtopic.php?t=9868 ) nicht sicher geklärt werden konnte, hätte ich ...

ulf wrote:

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

Nun, mein Motor (ALH) müsste ein Tuning rein thermisch besser wegstecken als zb ein ASZ, da ich den selben LLK wie die 110/115 PS Modelle hab ...

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 meinte dass man bei einigen Modellen keine Verbesserung mehr erzielen kann, daher frage ich mich inwiefern ein LLK-Upgrade eigentlich sinnvoll ist, wenn mit folgenden Nachteilen zu rechnen ist ->

Roger wrote:

je größer der LLK, desto größer ist das vom Lader zu füllende Volumen, bevor der Motor Druck sieht.

dj1 wrote:

ich habe vor kurzem meinen AFN einen zweiten LLK eingepflantzt. Der umbau hat eine weile gedauert und danach war ich im urlaub. Nach der ersten Probefahrt kams mir fast so vor als hätte er weniger Leistung als vorher!?

In welchen Dimensionen liegen die Leistungseinbußen ohne Tuning in etwa bzw ist ein LLK-Upgrade eintragungsfrei?

Danke

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 stronger TDIs with SMIC.

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 supercharger 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 only the cooling air side of an existing liquid-cooled system is optimized, then these disadvantages do not occur .

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

Rainer K. wrote:

Quote: Regarding Rainer's report, I can only say that the holes don't offer much benefit 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 quite effectively.

Does your A3 look the same?

On the Polo 9N, the SMIC 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 temperature reduction before the paint was removed.