LLK the 10th: Sizes and Performance Levels

Hello,

My engine (in its standard configuration) already produces up to 80°C of hot intake air at full load on the highway, even at an outside temperature of 13°C, while Rainer's A3 only needs to handle 50°C at an outside temperature of 19°C.
A difference of a "net" 36°C (at the same outside temperature)!

The air-to-water heat pump charges at 0.3 bar more than the water-to-water heat pump, but this doesn't necessarily mean a higher leaving water temperature (LWT). With a larger chilled water coil, it would still be possible to achieve 50°C LWT even with the air-to-water heat pump.

So, are the intercoolers in Rainer's TDI generation now oversized, or were they "trimmed" by cost-cutting measures in the 9N generation (or perhaps the air ducts to the intercooler were poorly designed -> causing misting before the intake, etc.)?

@ Motor experts:
Perhaps it would be helpful now if we could get some more detailed explanations about the internal motor consequences of different types of low-level therapy.
Gremlin had already provided some keywords for that.

Quote:

- firing pressure. - thermal load - compressed drive power - thermal efficiency

delivered.

Please provide the German text you would like me to translate into English. I will then give you only the translation, without any explanations.
Regarding thermal stress: As far as I know, the LLT (likely referring to a specific method or technology) approximately shifts the entire operating cycle, including the exhaust gas temperature, "in parallel," is that correct?

2.
The loader's power output could be reduced at lower LLT (Low Load Torque) if you don't want to change the air mass/stroke volume.
The logs from my altitude sensor show something different: high LLT (likely meaning "low limit temperature") leads to less boost pressure, possibly because of reason number 1, in order to prevent the temperature peaks from getting too high?

Unfortunately, I lack the background knowledge regarding ignition pressure and thermal efficiency. Could you please provide some guidance on these topics? Also, I would appreciate help with other aspects that are relevant to material stress and lifespan.


By the way, I once measured some LLK devices.

-> The frontal area of the cooling fins on the 1997 AFN Golf 3 (81 kW) is 14 x 19 cm, and the oil cooler is 6.5 cm deep. -> Volume of the cooling block = 1.73 liters.

-> Coolant reservoir in a 2001 ALH Ibiza (6K, 66 kW): Front dimensions are 9 x 30 cm, depth is 8 cm -> capacity of 2.16 liters.
The ASV-Ibiza, with its 81 kW engine, supposedly has the same coolant level sensor (LLS).

-> LLK (liquid cooling system) in the 2004 ASZ-Polo (96 kW): Front dimensions 18 x 20 cm, depth 6 cm. -> Also 2.16 liters, despite 44% more power than the ALH .
However, I believe that the larger frontal area of the ASZ-LLK is likely to have a (slightly) better effect on the LLK performance compared to the increased depth of the Ibiza.

It would be interesting to compare the dimensions of the LLK (liquid cooling kit) for the ARL engine and larger TDI engines (2.5L). Could someone measure them?

Hi Ulf,

Okay, here's the translation:

"Just a quick question: What's the actual difference between the 1Z/AHU and the AFN LLK engines in the VW Golf 3?"

To the best of my knowledge, AFN has a different one.

m;

Here's another contribution to your statistics:
My 1Z's LLT (Lower Limit Temperature) goes up to 30-35 Kelvin above the outside temperature, which roughly corresponds to Rainer's measurements.

Hi,

Without specific dimensions: If you look at the construction of the ARL (a type of railway vehicle) with its longitudinal load carrier running across the front of the car body, you'll see that it is significantly larger than that of the ASZ (another type of railway vehicle).
But remember, the larger the LLK, the greater the volume that the turbocharger needs to fill before the engine experiences boost pressure.

If that doesn't bother you, you could try replicating the construction of the more powerful 1.8T engine by using two intercoolers connected in series .

I can only talk about what's in the Skoda catalog right now.

LLK

1J0 145 803 F


MKB: AGU, AUM, AUQ, ARX, AGR, AHF, ALH, ASV, ATD


I'm not sure about ASZ either; unfortunately, my catalog doesn't go that far.

CU Gremlin.

LLK

1J0 145 803 F
AHF, ALH, AGR, AJM, AUY, ATD, ASV

1J0 145 803 E
ASZ

1J0 145 803 H
ARL.

dieselmartin wrote:

Just a quick question: What's the actual difference between the 1Z/AHU and the AFN LLK engines in the VW Golf 3? The AFN, as far as I know, has a different one.

As far as I know, all G3 TDIs have the same oil capacity, regardless of whether they are 90 or 110 horsepower models.

Roger wrote:

But remember that the larger the LLK, the greater the volume that the charger needs to fill before the engine experiences pressure. If that doesn't bother you, you could try the construction of a more powerful 1.8T engine using two intercoolers connected in series .

If I'm going to do it, I'll stick with one large intercooler: The Ibiza Cupra (1.9 TDI with 160 hp) probably inherited the ARL principle -> one giant intercooler in the front of the car.
What fits into the Ibiza should actually also fit into the Polo...

What is the purpose of connecting two liquid-cooled systems in series ?
Double boost pressure loss compared to a single intercooler, and the second intercooler is less effective because the intake air is already pre-cooled, resulting in a smaller temperature difference from the ambient air.

If I were to do it, I would connect the intercoolers in parallel: this would halve the pressure loss and provide a better overall effect because the charge air flows into both intercoolers at a "fully hot" temperature!

1H0 145 805 A
1Z, AHU, ALE, AFN

1J0 145 803 H
ARL

It is intended for ARL, ASZ, and AXR engines (only Golf/Bora), although I have never seen this plate cooler on the two weaker engines of the vehicle in question.

One more thought from me:

The charging capacity results from the product of the air intake volume flow and the pressure increase.

If the boost pressure is increased, then the pressure increase (by definition) and intake air volume flow increase, meaning that the turbocharger's performance increases roughly quadratically with the boost pressure (minus the change in air density due to heating).

With this nearly square increase in energy flow towards the motor, the liquid cooling system must now be completed.

Example AHF - ASZ: Boost pressure ratio 1:1.3 -> Turbocharger power ratio 1:1.69 with the same boost pressure limit.

If the goal is to achieve the same level of performance (LLT), then the liquid cooling system (LLK) would need to be approximately 70% more powerful.
The seemingly insignificant 25% volume increase of the LLK lamella block, for example, from AFN to ASZ, shows that the team consisting of developers and cost-cutters apparently tends to make compromises that lean quite heavily towards cost reduction.

ulf wrote:

What is the purpose of connecting two liquid-cooled systems in series ? Double boost pressure loss compared to a single turbocharger, and the second turbocharger is less effective because the intake air is already pre-cooled, resulting in a smaller temperature difference with the ambient air. If I were to do it, I would connect the intercoolers in parallel: this would halve the pressure loss and provide a better overall effect because the charge air flows into both intercoolers at a "fully hot" temperature!

It would be helpful to have some real-world data from a vehicle that has received its second Low Emission Zone (LEZ) sticker.
I still have two liquid cooling components lying around in my shelf, but it's too much of a hassle to install them because the silicone tubes are also very expensive.

What I still remember is that, for example, the Audi S3 has two coolant reservoirs, one on the left and one on the right.
It's roughly the size of an AFN engine. And the boost pressure in these vehicles is also incredibly high.

One more thought:

For example, the maximum injection duration (Pmax) is approximately 36 degrees of crankshaft rotation (KW) for an AFN engine, but only about 22 degrees KW for an ASZ engine.

This, in my opinion, results in an earlier termination of the afterburning cycle, which in turn generally keeps the exhaust gas temperature (EGT) lower.

This could potentially invite Mr. Cost-Cutter to interpret the LLK (Low Load Knock) aspect in the PD (Pre-Ignition Detection) system in such a (weak) way that the EGT (Exhaust Gas Temperature) remains at the "usual high" level by increasing the LLT (Low Load Torque) compared to VP (Variable Pressure) engines .

The difference in LLT (Low Load Torque) between Rainer's AHF (which I'm now equating with the AFN) and my car, which is about 36 Nm at maximum power, would actually fit into this concept, wouldn't it?

@ Ulf:

I've read quite a few things in this thread that I feel compelled to comment on.
The efficiency of an intercooler depends not only on its surface area and the external airflow, but also on the heat transfer from the charge air to the intercooler, which is significantly influenced by the internal flow velocity.
Consequently, the heat transfer between the charge air and the coolant in the intercooler system deteriorates significantly when two intercoolers are connected in parallel.
In a series configuration, while there is slightly higher pressure loss, the better heat transfer remains.

I would also be cautious about your volume-based size comparison estimate, as the surface area of the cooling fins is crucial and not the volume.
If the fin spacing of the liquid-cooled devices being compared is approximately the same, then this comparison can serve as a rough guideline; otherwise, it should not be used.

BTW: Does the ASZ actually meet the Euro 4 emission standard? If not, it might be due to the high load levels that increase NOx formation.

Regards,
Alex.

donalexo wrote:

but the heat transfer from the charge air to the intercooler is also significantly influenced by the internal flow velocity. Consequently, the heat transfer between the charge air and the coolant in the intercooler system deteriorates significantly when two intercoolers are connected in parallel. In a series configuration, while you experience a slightly higher pressure drop, you still maintain the better heat transfer.

Hi Alex,

That completely contradicts my gut feeling.

Theoretically, when two identical liquid-cooled components are connected in parallel, the internal flow velocity is reduced to half its original value.
That means the charge air remains in the intercooler for a longer time, and therefore has more time to dissipate heat.
And yet, less heat should be released per unit mass of air .

What processes (which are apparently unknown to me) are responsible for this?

Quote:

Regarding your volume-based size comparison estimate, I would also be cautious about that, as the surface area of the heat sinks is crucial and not the volume. If the compared liquid cooling blocks have approximately the same fin spacing, then this comparison can serve as a rough guideline; otherwise, it cannot.

Okay, that's not what I was trying to express either.

Quote:

By the way: Does the ASZ actually meet the Euro 4 emission standard? If not, it might be due to the high LNTs (Lean NOx Traps), which can increase NOx formation.

The ASZ only meets EU3 standards.

In EU4, it's called BLT and has practically the same upgrades as the 100 HP PD unit from EU3 that was carried over to EU4.
AGR water cooling, active AGR throttle valve, different PDE (positive displacement element), different catalytic converter, and strangely enough, a different turbocharger as well – the reason for this last change remains unclear so far.

To the best of my knowledge, the LLK (local language key) for the BLT (Bundesamt für Logistik und Verwaltung) is the same as that for the ASZ (Amt für System- und Zahlungsverkehr).

Just a quick question: What's the actual difference between the 1Z/AHU and the AFN LLK engines in the VW Golf 3?
The AFN, as far as I know, has a different one.
As far as I know, all G3 TDIs have the same oil capacity, regardless of whether they are 90 or 110 horsepower models.

But remember that the larger the LLK, the greater the volume that the charger needs to fill before the engine experiences pressure.
If that doesn't bother you, you could try the construction of a more powerful 1.8T engine using two intercoolers connected in series .
If I'm going to do it, I'll stick with one large intercooler: The Ibiza Cupra (1.9 TDI with 160 hp) probably inherited the ARL principle -> one giant intercooler in the front of the car.
And what fits into the Ibiza should actually also fit into the Polo...

What is the purpose of connecting two liquid-cooled systems in series ?
Double boost pressure loss compared to a single turbocharger, and the second turbocharger is less effective because the intake air is already pre-cooled, resulting in a smaller temperature difference with the ambient air.

If I were to do it, I would connect the intercoolers in parallel: this would halve the pressure loss and provide a better overall effect because the charge air flows into both intercoolers at a 'fully hot' temperature!

Unfortunately, due to another LLK (likely a technical term), the overall volume on the printing side also increases, and consequently, the response time is affected because this volume needs to be filled .

Quote:

Unfortunately, increasing the overall volume on the printing side through another

llk also increases the response time, as this volume needs to be filled.

Okay, see the 3rd post from above }.

Unfortunately, increasing the overall volume on the printing side through another also increases the total volume, and consequently, the response time, as this volume needs to be filled.

Okay, see the 3rd post from above .

Oops! I missed that!