LLK die 10te: Größen und Leistungsstufen | Posts 80+

Hello.

@ulf

Yes, exactly, LLT sensors at the enable/disable output.

The vehicles used for testing back then were a Corado G60 and a Golf 3 AFN TDI.

The LLT (likely lower limit) is approximately 15 degrees lower at the maximum power point (Pmax) when the outside temperature is 23 degrees Celsius.



Regarding Rainer's report, I can only say that the holes probably don't offer much benefit because they are simply too small. In my measurements, I always cut out the same area of the coolant reservoir. Also, he only measured "at the top, just before the intake manifold." Nevertheless, it's an interesting and well-written report.


Best regards, Cosi.

Hi Cosi,

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 the ventilation in the A3 is already so good that there's nothing more to improve. It might be different with other models.

The LLT (low-temperature lubrication) before the LLK (low-load lubrication) is irrelevant; what matters is what reaches the engine.

Best regards, Rainer.

Rainer K. wrote:

The LLT before the LLK is completely irrelevant; what matters is what reaches the engine.

Hi Rainer,

For experiments on the effectiveness of the liquid cooling system, the delta T between the inlet and outlet is an excellent measurement parameter .

Here are some pictures of my SMIC conversion.
I didn't order the red paint job ; the radiator builder did that on his own.

The grainy appearance comes from adjusting the size of the individual images.

The black tape provides extra water protection in case the foam pieces attached to the lower control arm (LCA) have become completely saturated with water, especially those located in the front apron (as part of the airflow system).

Looking at the distance between the upgraded engine cover and the wheel arch compared to the standard part, I also think that an outlet facing towards the wheel could further improve its performance.

I'm surprised that *you*, of all people, are accepting a painted heat exchanger.

Are you aware that the coating hinders heat transfer and also reduces the cross-sectional area of the fins?

rinderwahnsinn wrote:

Are you aware that the coating hinders heat transfer and also reduces the cross-sectional area of the fins?

Sure... I'm just waiting for a good deal on eBay for a nail polish remover set with 10 liters of nitro thinner, a container, and a LLK (likely referring to a specific brand) scrubbing pad .

Previous log data:
The new LLK (liquid cooling system) weighs approximately three times more than the original, at around 6 kg (heat storage capacity). This results in a significantly slower increase in the LLT (liquid cooling temperature) on the road, for example, when shifting to 3rd gear with full throttle from approximately 1300 rpm. LLT on the standard part: up to approximately 50 K above ambient temperature (AT). Upgrade: approximately 24 K above AT.
But on the highway (BAB), the advantage of the larger SMIC, for example, decreases from a certain point onwards (after 40 seconds in the Pmax range) to a mere 9-10 km/h.

@ulf: This is clear evidence that your new LLK (Low-Temperature Coolant) can extract more energy from the LL (engine), but it cannot release that energy to the environment. Your larger LLK absorbs energy during short-term temperature fluctuations, such as when accelerating on the highway, due to the larger mass of the aluminum LLK. However, the amount of energy that the aluminum mass can absorb is limited. The crucial factor is only how much heat the LLK can transport away from the outside – therefore, slits should help.

greetings

Rainer K. wrote:

Hi Cosi, 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 the ventilation in the A3 is already so good that there's nothing more to improve. It might be different for other models. The LLT (low-temperature lubrication) before the LLK (low-load lubrication) is irrelevant; what matters is what reaches the engine. Greetings, Rainer

Hello.

Do you mean the holes that are cut out in the front or the back of the bumper?
I meant that the holes on the back are too small. It's not just about the airflow, but also about the radiation losses of the LED light. It performs significantly better when the wheel well is "open."
The idea of using two sensors was to have reliable reference values, and it's naturally more accurate and informative than the original sensor, which is located higher up and is still affected by the engine's ambient temperature.

P.S. My previous comment was in no way intended as criticism .


Best regards, Cosi.

Devilseye503 wrote:

With prolonged stress, the energy that the aluminum mass can absorb is depleted - the crucial factor is only what the LLK (likely referring to a specific component or system) can transport away externally - so slits should help.

...unless the weakness lies in the cooling air side (which, given the data mentioned above, is probably unlikely).

I'll try using slits and post the results.

Okay, so I drove today with 5 cuts in the fender liner, located behind the left-hand side coolant reservoir.
The slots are angled downwards towards the wheel to prevent the back of the LLK (likely referring to a specific component) from becoming stuck with dirt from the tire.

The total cross-sectional area of the slits is estimated to be in the order of 60 cm².

Result:
The gain is approximately 2.5 K, meaning that the LLT (Low-Level Turbulence) at Pmax (maximum power) on the highway at a speed of 200 km/h is now about 12 K lower (42 K above ambient temperature) compared to the standard LLK (Low-Level Kit) without slits.
It takes a lot of effort for the squirrel to find food.

It's possible that the increased depth of the LLK (likely referring to a liquid-cooled system) has increased the flow resistance of the channels to such an extent that, given the existing static pressure before the LLK, less air flows through the channels than with the original LLK. Additionally, the paint layer might be isolating too much.
Or perhaps the airflow is insufficient. Do you happen to have any pictures of it installed, with the front spoiler?

joegolf wrote:

Do you perhaps have pictures of it installed, with the front bumper?

Currently, please refer only to my signature: the double image with the modified cooling air intake (scroll down a bit in the link).

Currently, I'm even driving without the fog light, using the corresponding spoiler grille without the tube that surrounds the fog light. Just imagine the picture without the fog light, with continuous horizontal ribs in the grille, and with a slightly wider airflow path between the grille and the intercooler.
The cooling air intake, with a total area of approximately 220 cm², already looks quite generous.
(Normally, the 9N front grille for cars without fog lights and with a low coolant level sensor has approximately 90 cm² of open inlet area between the ribs.)

Nevertheless, my 220 cm² might still be a bit small compared to the approximately 300 cm² of fin area on the front surface of the SMIC.

Okay, before I cut any more holes in the front bumper, I'm going to enlarge the "gills" in the wheel arch a bit more to achieve the largest possible total airflow area for the hot exhaust air.

At least, I've already broken the rule of thumb of 10K, which is sometimes mentioned as the best possible result for SMIC conversions, by achieving a reduction of approximately 12K LLT.

ulf wrote:

joegolf wrote: Do you perhaps have pictures of it installed, with the front bumper? Nevertheless, my 220 cm² might still be a bit small compared to the approximately 300 cm² of fin area on the front surface of the SMIC. Okay, before I cut any more holes in the front bumper, I'm going to enlarge the "gills" in the wheel arch a bit more to achieve the largest possible total airflow area for the hot exhaust air. At least, I've already broken the rule of thumb of 10K, which is sometimes mentioned as the best possible result for SMIC conversions, by achieving a reduction of approximately 12K LLT.

Hello.

Well then. That aligns with my experiences and measurements.



@Rainer


I think that confirms what I "complained" about to you.
As I said, my previous statement was in no way intended as criticism.


Best regards, Cosi.

Cosi wrote:

This aligns with my experiences and measurements.

Hi,

At this point

Quote:

, the LLT (Low Leaving Temperature) is approximately 15 degrees lower at Pmax when the outside temperature is 23 degrees.

However, my experience is only about 13% (so approximately 2 K) of yours - and I always evaluate the LLT and its changes relative to the outside temperature according to the MFA (Multi-Function Display), since I don't have an LLK (Low Leaving Temperature) input sensor.

Despite the significantly larger air outlets in the wheel arch liner, the LLT was not noticeably cooler.

Tomorrow, I'll try another test run without the spoiler grid, meaning with approximately 50% more intake area for the cooling air. If this doesn't result in any further reduction in low-temperature torque (LLT), then the upgraded SMIC (super міні-intercooler) is likely at its limit.

I think a very good way to optimize it would be to add an air deflector for your liquid cooling system – the ARL-LLK also has one, even though it's mounted on the front.

greetings

Devilseye503 wrote:

I think a conceivable good option for optimization would be an air deflector for your LLK

.
Yes, something similar has been on my mind today.

Without the spoiler grille, the LLT (lift-off turbulence) decreased from approximately 42 to 38 kPa above the AT (in each case at 1.4 bar / 200 km/h / 4000 rpm), even though the grille doesn't actually take up that much airflow area - see the attachment.
The black area behind the right half of the grid is a guide surface that is positioned at a rather steep angle of approximately 45 degrees, and it may hinder the airflow rather than improving the intake of the cooling liquid .

Therefore, I suspect that the most important thing is to direct the airflow with the highest possible (residual) velocity onto the LCC.
...so that without first slowing him down and converting his energy into (stagnation) pressure, which then forces the air through the cooling system.
Because in this process, a significant amount of energy is lost, which manifests as a slower flow of electricity through the network, resulting in reduced cooling capacity and a higher LLT (likely referring to a specific temperature or performance metric).

Therefore, I will try to modify the grid in such a way that it minimizes the disruption of the airflow and introduces guide surfaces between the grid and the cooling fins.

Hello.

@ulf


Just for your information. In my measurements back then, it was completely rectangularly cut out. Unfortunately, I don't have any pictures from that time. I did that around 1996.

It wasn't just out of personal interest; it was "for business" purposes. When you want to develop and sell performance kits, you have to try a lot of things and also provide evidence. That's why there was so much effort involved.

Ich bewunder sowieso wie du, Rainer und manch anderer hier solche Sachen probiert, testet und auch dokumentiert . Compliment...


Best regards, Cosi.