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

Hello.

@ulf

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

The test vehicles at that time were a Corado G60 and a Golf 3 AFN TDI.

The LLT (likely lower limit) is approximately 15 degrees less 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 (LLK) from the back. Also, he "only" took measurements near the top, just before the intake manifold. Nevertheless, it's an interesting and well-written report.


Best regards, Cosi.

Hi Cosi,

Quote:

Regarding the report from Rainer, 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 air filter before the air mass meter 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 liquid cooling materials, the temperature difference (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 if the foam pieces attached to the lower lip of the bumper have become completely saturated with water, especially those located in the front spoiler (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 coated 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?

Of course... 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 solvent-based cleaning pad brush .

Previous log data:
The new LLK (liquid cooling system), with a mass approximately tripled to around 6 kg (heat storage capacity), results in a much slower increase in the LLT (liquid temperature) on country roads, for example, when shifting from 3rd gear to full throttle at approximately 1300 rpm. LLT on the standard part: up to about 50 K above ambient temperature (AT). Upgrade: an increase of 24 K above AT.
But on the highway (BAB), the advantage of the larger SMIC, for example, decreases from a certain point onwards within the maximum power (Pmax) range and converges to around 9-10 km/h .

'@ulf: This is clear evidence that while your new oil cooler can extract more energy from the engine oil, it cannot dissipate that heat to the environment. Your larger oil cooler absorbs energy during short-term temperature fluctuations, such as when accelerating on the highway, due to its greater mass of aluminum. However, the amount of energy that the aluminum mass can absorb is limited. The crucial factor then becomes how much heat the oil cooler can transport away externally – therefore, slits should help.'
greetings

Rainer K. wrote:

Hi Cosi, Quote: Regarding the report from Rainer, 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 air filter before the air mass meter is irrelevant; what matters is what reaches the engine. Greetings, Rainer

.

Hello.

Do you mean the holes that are cut out at the front or back of the bumper?
I meant that the holes on yours are too small at the back. It's not just about the airflow, but also about the radiation losses of the LED light. The performance is 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 can be 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 then becomes only what the LLK (likely referring to a specific component or system) can transport away externally – therefore, slots should help.

...unless the weakness lies in the cooling air side (which, based on the data mentioned above, seems unlikely to me).

I'll try using slits and post the results.

Okay, so I drove today with 5 cracks in the fender liner behind the left-hand side coolant reservoir.
The slots are angled downwards towards the wheel to prevent the back of the luggage carrier from becoming covered with dirt from the tire.

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

Result:
The gain is approximately 2.5 Kelvin, meaning that the LLT (Low Level Turbulence) at Pmax on the highway at a speed of 200 km/h is now about 12 Kelvin lower (42 instead of 54 Kelvin 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 liquid coolant (LLC) has raised the flow resistance within the channels to such an extent that, given the existing pressure before the LLC, less air flows through the channels compared to the original LLC design. Additionally, the paint layer might be too insulating.
Or perhaps the airflow is insufficient. Do you happen to have any pictures of it installed, with the front spoiler in place?

joegolf wrote:

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

Currently, please refer only to my signature: the double image with the modified cooling air intake (you'll find it by scrolling down a bit in the link).

Currently, I'm even driving without the fog light housing. It uses 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 a slightly wider airflow path between the grille and the intercooler.
The cooling air intake, with a total area of approximately 220 square centimeters, is already quite generous in size.
(Normally, the 9N front grille for cars without fog lights and with a low coolant level sensor has approximately 90 square centimeters 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 further to achieve the largest possible total airflow area for the warm 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 in place? 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 further to achieve the largest possible total airflow area for the warm 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 earlier.
As I said, my statement above was in no way a criticism.


Best regards, Cosi.

Cosi wrote:

This aligns with my experiences and measurements.

Hi,

At this point

Quote:

, the LLT is approximately 15 degrees lower at Pmax when the outside temperature is 23 degrees Celsius.

However, my experience is only about 13% (so roughly ~2 K) of yours - although I always evaluate the LLT and its changes relative to the outside temperature according to the MFA, as I don't have an LLK input sensor.

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

Tomorrow I'm going to try another measurement run without the spoiler grid, meaning with approximately 50% more intake area for cooling air. If this doesn't result in any further reduction in low-temperature torque (LLT), then the upgraded SMIC (super мініатюрний інтеркулер) is probably at its limit...

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

greetings

Devilseye503 wrote:

I think a conceivable good way to optimize would be an air deflector for your liquid cooling system

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

Without the spoiler grille, the LLT (lift-off tension) decreased from approximately 42 to 38 kPa above 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 attachment.
The black area behind the right half of the grid is a guide surface that stands at a rather steep angle of approximately 45 degrees, and it may hinder airflow more than it improves the intake for the liquid cooling system .

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 (pressure), which then forces the air through the cooling system.
Because in this process, a significant amount of energy is likely lost, which manifests as slower network throughput, reduced cooling capacity, and higher latency (LLT).

Therefore, I will try to modify the grid in such a way that it minimizes wind resistance or turbulence, and also incorporate 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 proof. 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.