Fabia RS PD 170PS starker Leistungsverlust | Posts 112+

@Mr. Antje

You're confusing something.
Thermal overload on the exhaust side due to improper or cheap tuning can damage components like turbochargers, variable turbine geometry (VTG) units, and valves much faster.
LLT (Low Temperature Combustion) certainly plays a role, but it's less related to a combustion process that is ~300 degrees hotter. I am not aware of the extent to which high exhaust gas temperatures are correlated with high LLT.

"The Kühler is definitely better because it achieves the same performance with lower LD (lambda value), aside from the fuel injection amount."

@ulf

Sorry:
It was about 85 degrees Celsius above the outside temperature.

Successful tuning:

I doubt the tuner's performance specifications are accurate after the first round.

"Overpressure up to 26 mbar, then settles at approximately 2370." "Ambient pressure: 930 mbar."

The delivery is scheduled for between 15:00 and 17:11.

@Mr. Antje

You're confusing something.
Thermal overload on the exhaust side due to improper or cheap tuning can damage components like turbochargers, variable turbine geometry (VTG) units, and valves much faster.
LLT (Low Temperature Combustion) certainly plays a role, but it's less related to a combustion process that is ~300 degrees hotter. I am not aware of the extent to which high exhaust gas temperatures are correlated with high LLT.


Mr. Antje isn't entirely wrong about this.
If you cause the intake air temperature to become too high due to improper tuning (excessive boost pressure), you will damage your intercooler. Unfortunately, plastic intercoolers cannot withstand infinitely high intake air temperatures.
We're always talking about the temperature after the radiator, where the low-temperature coolant (LLK) is already relatively cool. However, you can't see what the temperature is *before* the LLK, or whether that part of the system is thermally stressed, because there's no corresponding sensor for it in VAG-Com.

If the cooler is overloaded, it can deform, potentially causing the air hose to come loose and the turbocharger to overspin. The engine control unit (ECU) doesn't even detect this directly; only the excessively high control difference triggers the engine to go into limp mode.

Let's have an example here to establish some temperature ranges:
A standard diesel engine with 150 horsepower (I won't say more about that for various reasons) is pulling a trailer loaded with goods and is climbing a 15% grade in second gear.
LLT before LLK: 191°C, after LLK: 82°C. Luckily, the LLK was rated for 200°C.

YOU had 110°C after LLK .

Best regards,

Okay, the first tuning log file is complete.

Three consecutive times in third gear up to 4500 RPM at an outside temperature of 17 degrees Celsius.

@ulf Is there anything unusual in the logs besides LLT?

LOG: /download.php?id=1644

I'm a bit disappointed with the meager result. According to the Skoda workshop, another RS is running at 1.6 bar of boost pressure. Why am I getting less? The measured external pressure was around 930 mbar on my gauge, and 1.6 bar was only a momentary spike.

@Jochen_145

I had high LLT values in the series trim that led to a reduction in LD with the old control unit, which was my original problem.

The STG (engine control unit) is not interested in the high LLT (lambda learning target), as proven by the test with a hidden LLK (liquid-cooled intercooler) and a temperature of 117 degrees. Today, even with chip tuning and full throttle, I managed to reach 75 degrees above ambient temperature, which means a maximum of 105 degrees in high summer for just a few seconds, only in third gear.
In any other gear, the maximum speed reached is 90 degrees.

In general tuning, increasing the fuel injection duration and lambda (air-fuel ratio) automatically leads to higher temperatures, both in the combustion process and in the exhaust gas temperature (EGT).

I haven't heard anything about leaking IV fluids or tubes yet.

While conceivable, it's certainly not the standard practice when considering systems with a 1.5 bar pressure and a "Fraktion" (likely referring to a specific component or group), especially given the use of "serienllk" (possibly a typo for "series link") and a 20-degree lower LLT (Likely Low Leaving Temperature).

You hear more about issues like stuck VTG (variable turbine geometry) units, turbocharger damage, or head gasket failures.
Turbos don't always fail due to excessive load; they can also be damaged by excessively high exhaust temperatures from the exhaust valves and cylinder head.

Incorrect tuning: "10c, p-poxen, extreme performance enhancements, reckless drivers."

Comparing an ARL to a car with an ASZ engine? There's a significant hardware difference in terms of things like the LLK (likely referring to a charge air cooler) and turbocharger!

super7 wrote:

@ulf Is there anything unusual in the logs besides LLT? I'm a little disappointed with the meager result...

I can imagine: the target LD value corresponds to the series settings, and otherwise, it seems your tuning software doesn't really know what it's doing [edit] except how to protect the clutch [/edit] -> have them give you back the original software and find a better tuner, then the car will run properly .

I won't say any more... I have no reason to give tutoring to likely substandard tuners, and Rainer knows how to do it properly .

@Jochen_145

The STG (engine control unit) is not interested in the high LLT (lambda target value), as proven by the test with a hidden LLK (charge air cooler) and a temperature of 117 degrees. Today, even with chip tuning and full throttle, I managed to reach 75 degrees above ambient temperature, which means a maximum of 105 degrees in high summer for only a few seconds, specifically in third gear.
In any other gear, the maximum speed reached is 90 degrees.


This is not a good approach.
Just because the temperature limit has been reprogrammed doesn't mean everything is okay.
I don't think you really understood what I wrote.

With VAG-Com, you can only see the coolant temperature (LLT) located behind the intercooler. Everything that happens between the turbocharger and the intercooler in terms of temperature is unknown because there are no sensors installed in that area as standard.
If you excessively increase the turbocharger boost pressure (which is not good tuning, as Mr. Antje also mentioned), you will damage the engine's components. This, like excessive exhaust temperatures, can lead to engine failure.
The air charge temperature before the intercooler increases proportionally to the boost pressure. If the standard cooler is already struggling, increasing the boost pressure through tuning will certainly not improve the situation.

In my example, you can see how much LLT (Low-Level Turbulence) can be reduced by using an LLK (Low-Level Kit). Calculate this based on your own LLT values. Your LLK will not have better temperature resistance because it is also made of plastic.


I haven't heard anything about leaking IV fluids or tubes yet.


I didn't write that either.
It's about thermal overload.


While conceivable, it's certainly not the standard practice when considering systems with a 1.5 bar pressure and a 'Fraktion' (likely referring to a specific component or group), especially given the use of 'serienllk' (possibly a typo for 'series link') and a 20-degree lower LLT (Likely Low Leaving Temperature).


'When I run at 1.5 bar of boost pressure, my engine seems to have a noticeably different oil level reading. Why is that? Is it perhaps because the oil I'm using looks better?'
You only build something like that if the small, cheap one is absolutely no longer working; otherwise, you're losing money!
If I have 20,000 fewer LLT units, the inlet temperature for the serial LLK process will also be lower.


You hear more about issues like stuck VTG (variable turbine geometry) units, turbocharger damage, or head gasket failures.
Turbos don't always fail due to excessive boost pressure; they can also be damaged by excessively high exhaust temperatures coming from the exhaust valves and cylinder head.

Incorrect tuning: '10c, p-poxen, extreme performance enhancements, reckless drivers.'

Comparing an ARL with an ASZ? There's a significant hardware difference, including things like LLK (Low Load Knock) and Turbo!

And far too high boost pressure. Please refer to the technical articles for more information on this topic.
A good tuner isn't defined by high boost pressure, but rather by the ideal balance. It should have as little boost as possible to avoid overstressing the turbo and exceeding its maximum safe operating speed (RPM), while still providing enough boost to minimize excessive fuel enrichment.

What do you think is the reason for the differences in hardware between the engines mentioned above?
Best regards,

Jochen_145 wrote:

If I have 20k fewer LLT units, the inlet temperature of the serial LLK will also be lower.

...or the cooling airflow was significantly improved.
If you utilize all the available options on a 96kW 9N (without removing or modifying the front bumper to accommodate the SMIC), then lowering the ride height by approximately this amount is possible. Importantly, this can be achieved without any software modifications, meaning with the same intake air temperature at full load.

Thank you, Jochen_145! I don't need to defend my statement anymore .

Off-Topic:

super7 wrote:

@Mr. Antje She

@super7
I am Tom and I am 32 years old. You don't need to address me formally; besides, that's not how things are done in a forum. I am Dutch (that's why the name; "Frau Antje" was too feminine for me ), but we don't take things *too* seriously about it. So, "Herr" is just a nickname.

@ulf

He who suffers the damage will be the object of ridicule!

A factual and objective explanation would help me understand the logs, as I could then justify my actions to the tuner instead of having to drive forward three more times just to tell him what a mess his tuning parameters are.

My diesel killer.

The references he can provide are simply amazing, including mentions on television where he was described as a good, reliable, and trustworthy technician. "DE Television praising an AT tuner??".

Would anyone entrust a Milotec Fabia RS tuning project, costing €100,000 and featuring a 320hp TT engine, all-wheel drive, and sequential transmission (currently being tested for dyno tuning), to a "noodle tuner" for adjustments, and then transport it another 1500km by truck?
The workshop offers international services for tuning, modifying, and optimizing cars.

It was simply impossible to foresee that my attempt at modifying my car would go so wrong, especially when you see the motorsport-ready vehicles in the yard where the modifications cost five times more than my entire car.

Again: Another 2.RS has been running with the same tuner at 1.6 bar of boost for 60,000 km without any issues or smoke.

Without a VAG-COM diagnostic tool, I would think everything is fine.

I spoke with Tuner on the phone:

Tomorrow morning, the boss will personally inspect what doesn't fit or is wrong with my car or its modifications.
The tuning has been done unofficially so far by mechanics from the tuning company, except for the engine maps, for which I have a receipt.

On the edge:

Another option to add to my high LLT.

I live 900 meters above sea level, and my test drives extend up to 1300 meters above sea level, which would explain a lot.

Thinner air for cooling and more work for the turbo to achieve higher load.

It just occurred to me that at various motorsport events, cars have been experiencing problems with engine tuning due to "thinner air."
Aussage von div. Racers.

For vehicles with turbochargers, there is certainly a higher thermal load, both in terms of engine temperature and oil level temperature.

There is something like a "height protection" map, source: https://community.dieselschrauber.org/en/viewtopic.php?t=12892.

I think the rest should be sorted out by your tuner. If the second RS is running smoothly, it should check your software settings more closely. The comparison with the second RS was definitely done at the same altitude, right?

Hi,

Typically, as altitude increases (and air pressure decreases), the boost pressure is reduced to prevent overloading the turbocharger. If you're maintaining the same boost pressure at 1300m as you would at sea level, I'm not surprised that the turbocharger is spinning too fast, the efficiency drops significantly, and the lambda value increases so much. Please check the ambient air pressure reading from your MWB 10 (value 2) and post it.
A partial solution might only be achieved with a larger battery pack, but this wouldn't eliminate the high load on the charger if the same motor power is required as in the current state.
Personally, I wouldn't expect to get 170 horsepower from the ASZ (?), and I certainly wouldn't program that into the software.

Best regards, Rainer.

super7 wrote:

I live 900 meters above sea level, and my test drives extend up to 1300 meters above sea level, which would also explain a lot.

Okay, at normal atmospheric pressure at sea level, you would have approximately 900 millibars of ambient pressure at an altitude of 900 meters (this is a coincidental numerical equality), and around 850 millibars at an altitude of 1300 meters.
At 900 millibars, the standard LD target is reduced to 2275 millibars, and at 850 millibars, it is reduced to 2230 millibars (within the range of approximately 2500 rpm).
"In your log, the target pressure reaches a maximum of around 2330 millibars. Therefore, depending on the altitude and actual outside pressure, there's an increase in line drive (LD) of roughly 60 to 100 millibars – which is relatively small, but well..."
To gain more clarity, you should probably descend to an altitude of around 300 meters and take some more measurements there.
To get a more detailed look at your software, the following test cases (MWB 001, 008, and 010) would be helpful. Perhaps it performs as expected in simple scenarios, but I have some initial doubts...

Quote:

The tuning has been done unofficially so far by mechanics from the tuner company, except for the engine maps for which I have a receipt.

Um Are the individual prices listed on the invoice?
What is the purpose of modified parameter sets without the rest of the MSG file?

I would like to see the invoice (or at least some text excerpts from it regarding the delivered "goods" or service) .

Quote:

Just ask him why the LD target hasn't been increased, even though it's done with almost every basic tuning.

Perhaps because otherwise, charger defects would noticeably increase at this level without a meaningful adjustment of other parameters?

I'm curious to see what's on the bill .

To the professionals:
Could it be that his engine file is correct, but the target boost pressure (and actual boost) isn't reaching 1.6 bar because the boost is already being reduced due to altitude (or low air pressure)? In other words, the tuning maps are fine, but the tuner didn't adjust the overboost protection settings, perhaps to avoid the risk of damaging the turbo?

What happens when a vehicle (let's say in its standard configuration) enters this low-pressure zone? How is the boost pressure reduced – through a target value, or also via duty cycle? Does it remain permanently in the soot reduction mode, or are other parameters like engine speed and driver demand also adjusted? Or put another way, how can you tell if you don't have the boost pressure value memorized?

If my questions are too silly, just ignore them . However, depending on the answer, it could be an indication of how to evaluate the file from super7.

Rainer K. wrote:

Quote: Just ask him why the LD target hasn't been increased, even though it's done with almost every basic tuning. Perhaps because otherwise, charger defects would noticeably increase at this level without meaningful adjustments to other parameters?

Well, considering the altitude of the location, the target LD (likely referring to a light level or similar parameter) is probably higher than initially thought -> see the edit above.