Überschwinger 150 PS (ARL) | Posts 32+

Wo liegt das Problem ?


Das man IN den file nicht 'rein' gucken kann?!


Also kann man es doch. Ich stell den file gerne zur Verfügung. Mein tuner den ich nur pos. weiter empfehlen kann, wird das sicher nicht gerade erfreuen.


Knowing how to bypass the 'NoRead' protection without any problems is crucial. At the very latest, if you desolder the flash memory. It then takes a marginal extra 10 seconds.


Sorry mulle, ich wollte dich jetzt nicht angreifen.

I didn't quite understand that either. [/quote]

I wasn't really in the mood to solder. Is there another way to do this? Like, can I read it out as a "package"?

Jochen_145 wrote:

Quote: Every charger would have to be able to disconnect and reconnect an arbitrary number of times, for example, at 4000 or more rpm during the transition from thrust to full load to deliver arbitrarily high pressures for a duration of 6 seconds . To be honest: 1) ja, das sollte eigentlich so sein, denn eine LD-Erhöhung von 0,2bar bei 30% Mehrleistung ist eigentlich normal. Der Lader hält dies dauerhaft aus.

(2. Anrun)

Hi Jochen,

With this answer, you have skillfully steered me away from the greatest danger (which I had already described in a technical article on LDA some time ago ): namely that even with a VTG that is jammed in the closed position, the emergency brake will not be activated until approximately 6 seconds "at least 0.3 bar above the set point."

Imagine your VTG (Variable Turbine Geometry) is constantly being forced into a closed position due to a minor pneumatic defect (e.g., a speck of dirt blocking the EPW - Exhaust Pressure Wastegate). You're driving your car normally, meaning you never give it full throttle for more than 6 seconds at a time above 2000 rpm (below 2000 rpm, the EDC15 doesn't go into limp mode, regardless of how large the control error is).
Then you encounter a long semi-trailer truck on the highway that's traveling at 60 km/h. You shift into 3rd gear (approximately 2400 rpm) to overtake and keep your foot fully on the accelerator until you pass the truck.
What do you estimate the engine's RPM at full throttle to be when the exhaust system transforms into fine particulate matter due to the forced-closed VTG (Variable Turbine Geometry)? If the thrust then collapses, it's not an early emergency mode caused by extreme boost pressure, but rather the engine sputters and dies because there is no more boost.

If you believe the OEM fail-safe parameters are reliable, you would be convinced that in this example, the turbocharger would last up to approximately 4500 rpm (which is 6 seconds of full throttle from 2400 rpm) before being released from the fail-safe mode. And it could do this repeatedly, as long as a DAF*) starts afterward (each time after the engine is turned off and on), allowing you to reliably demonstrate the phenomenon to the workshop...

*) Assuming "DAF" refers to some specific diagnostic or testing procedure.*) Least Qualified Driver

The turbocharger only over-revs when it needs to deliver a flow rate that it is not capable of handling.
'Speaking of which, at 4000 rpm, for example, an overshoot of 0.2 bar will certainly be problematic. At 2000 rpm, however, with the same boost pressure, it only has to handle half the volume flow. Therefore, according to the pi x diameter principle, an overshoot greater than 0.4 bar is likely to become problematic. Here, the pump limit is more likely to be the problem.'

Hello everyone,

Okay...
I just discussed the topic again with a colleague who is very knowledgeable about turbochargers.

I have a problem with the above-mentioned.
Diese Annahme gilt allein für einen Bypass-Lader.

Here, the overcentering mechanism works exactly as I described, because the loading force is directly proportional to the motor speed.
Demnach waren meine Turbo-KV doch von einem Bypasslader...

With the VTG loader, the loading speed is proportional to the valve position and independent of the engine speed.

Therefore, the charging rate is higher at low engine speeds than at high speeds, where the variable geometry turbine (VTG) is correspondingly more open.
Similarly, the load increases accordingly at low speeds.

Therefore, the over-revving is significantly more damaging at low RPMs than at high.

Therefore, just as Ulf and Rainer practice it, the overtravel on VTG loaders should be kept as small as possible and ideally remain at the same level as the standard application.

Every overclocker is already a compromise of long-term reliability.
Je öfter ich Überschwinge, desto früher stribt mein Lader. Dies gilt auch für die Serie !
Therefore, each increase in engine power through tuning shortens the lifespan, as the designed service life is only for the standard configuration. (An exception to this might be the 90hp VTG-TDI, ALH?).

@Ulf,

The programmed limits are valid for an operation that is restricted by the regulations. With these parameters, I am already exceeding the expected lifespan during serial application.
Therefore, from a mechanical perspective, one should use LD_max = LD_max_Series - additional LD increase.

A VTG valve that is stuck in the closed position will inevitably lead to the destruction of the charger. This can also happen before the time limit expires.


Generally speaking, about turbos in standard chargers:

The OEM currently has absolutely no reserves for turbochargers in its inventory (IDR).
Therefore, different types of chargers are used today for different power levels.

The background is that in Germany, taxes are based on engine displacement, not horsepower.
Therefore, the original equipment manufacturer (OEM) would be unnecessarily sacrificing performance and thus expertise if they didn't fully utilize the potential of the charger.

Best regards, Jochen.

Jochen_145 wrote:

With the VTG loader, the loading speed is proportional to the valve position and independent of the engine speed. Therefore, the charging rate is higher at low engine speeds than at high speeds, where the variable geometry turbine (VTG) is correspondingly more open. Similarly, the load increases accordingly at low speeds. Somit sind die Überschwinger bei niedrigen Drehzahlen deutlich schädlicher als bei hohen.{MARKER: Hi Jochen. That surprises me again, but suddenly in the opposite direction... I can imagine that there might have been some misunderstanding. Take a look at the red speed lines at the bottom of the diagram.

Our VTG chargers all still have a "conventional" compressor (only the turbine is different from the wastegate type). Therefore, the diagram should generally be applicable to the compressor side of VTG-TDIs.
Simplified:

The charger's rotational speed increases "approximately proportionally" to the load (LD, on the Y-axis).

2. With the same air density (LD) and increasing volumetric flow rate (X-axis), the motor speed remains relatively constant, while the turbocharger speed initially stays almost constant as well. Only near the compressor surge limit does the required rotational speed increase in order to maintain the desired LD (with the same turbocharger speed, the LD decreases). Presumably, this is why the target values for LD begin to decrease slightly below the rated speed, because the compressor surge limit becomes "imminent."
In my opinion, this implies that a specific boost pressure X (within the range to the right of the pump's limit) ...
a) requires approximately the same turbocharger speeds in the lower and mid-range engine speed range.
b) Higher turbocharger speeds in the upper engine speed range are conditional, meaning that over-boosting (overswinging) is most critical for the turbocharger in the upper engine speed range.http://www.turbos.bwauto.com/products/turbochargerCompressor.de.aspx

Take a look at the red speed lines at the bottom of the diagram:
http://www.turbos.bwauto.com/products/turbochargerCompressor.de.aspx
Our VTG chargers all still have a 'conventional' compressor (only the turbine is different from the wastegate system). Therefore, the diagram should generally be applicable to the compressor side of VTG-TDIs.

Exactly such a diagram was the basis for my statements yesterday.
This probably only applies to bypass loaders.

That's where the error lies in my statements above.

In a VTG (Variable Turbine Geometry) system, the turbine speed is directly proportional to the vane position.
The tighter it is closed, the greater the pressure inside the housing, and the higher the impeller speed.
You'll only find the closed-throttle position at low engine speeds, which means that high turbocharger speeds can only occur at low engine speeds.

Diese 'Antilinearität' macht für mich das Verständnis sehr schwer...
A turbocharger speed that is proportional to both boost pressure and engine speed would be much easier to understand.

Perhaps someone can explain this in detail someday...

At the very least, for VTG loaders, it can be said that overswing in the low RPM range should never be greater than at high RPM.

Best regards, Jochen.

Quote:

Bei einem VTG ist die Laderdrehzahl jedoch proportional zur Klappenstellung.

Sure?

I'm closing the flaps manually.

Even when idling, there's still no boost pressure, but it does build up at higher RPMs and under load.

This is a counterexample to your statement.

I would say that with a VTG (Variable Turbine Geometry), you have one (half) degree more freedom. The wastegate only has half an F-degree.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Jochen_145 wrote:

Bei einem VTG ist die Laderdrehzahl jedoch proportional zur Klappenstellung. The tighter it is closed, the greater the pressure inside the housing, and the higher the impeller speed. Die geschlossenstellung findest du jedoch nur bei niedrigen Drehzahlen, somit können hohe Laderdrehzahlen nur bei niedirgen Motordrehzahlen entstehen.

That is only half the truth; a more accurate statement would be "proportional to the valve position multiplied by the exhaust flow".

The VTG (Variable Turbine Geometry) will be closed to extract the maximum turbine power from the low exhaust energy in the speed range where it's less efficient. This is precisely the main advantage compared to a wastegate system.

As the exhaust gas flow increases, the variable geometry turbine (VTG) is gradually opened to prevent the low-pressure ratio (LD) from becoming too high.
That doesn't mean the turbocharger speed decreases! Instead, at maximum engine load and increasing engine speed, the turbocharger speed is likely kept approximately constant by the variable turbine geometry (VTG) system, roughly near the upper red line in the BWT diagram (or just below it), so that the actual boost pressure corresponds to the desired boost pressure.

Quote:

Exactly such a diagram was the basis of my statements from yesterday. Dies gilt wohl aber nur für die Bypass-Lader..

Since the design of the compressor and the engine behind it are fundamentally the same, the compressor diagram also applies to wastegates and variable turbine geometry (VTG) turbochargers, as long as the turbine provides the necessary drive power or speed.
Certain differences in turbine pressure requirements and, consequently, in the total gas flow rate do not change the principle, and the BWT diagram does not describe anything more than that.

Quote:

Therefore, as Ulf and Rainer practice, the overtravel on VTG chargers should be kept as low as possible and ideally remain at the same level as the standard application.

This remains correct .

Sicher ??

NEIN...

'Sorry Martin, but I'm not entirely sure; I'm actually trying to understand what I was told. This is the statement from someone who worked with VTGs for 2.5 years.'

However, I would agree with that statement from an acoustic perspective.
My loud turbocharger is loudest in the range below 2000 rpm, especially when the throttle valve is mostly closed. I've noticed that as the engine speed increases, the frequency (presumably referring to a noise or vibration) and thus the perceived engine speed seems to decrease.


I would say that with a VTG, you have one (half) degree more freedom. The wastegate only has half an F-degree.

Yes, the exhaust volume must also be taken into account by IMA.

@Ulf,

Yes, that sounds plausible, but it would also support my initial theory, which suggests that the turbocharger's speed is determined by the volume of air being forced through it.

However, at full engine load and increasing engine speed, the turbocharger speed is likely kept approximately constant by the variable turbine geometry (VTG) .

I've also heard that statement before in connection with VTG.

As I said, I don't know the exact answer right now.


Best regards, Jochen.

Jochen_145 wrote:

In a VTG (Variable Turbine Geometry), the impeller speed is proportional to the valve position... Dies ist die Aussage von jemanden, der 2,5 Jahre mit VTGs gearbeitet hat.

It's not wrong per se, but it's incomplete because it doesn't account for changes in engine speed and load.
Just talk to him about it again. Or is he one of those temperamental gurus whose statements you're not allowed to question?

Quote:

Mein lauter Seat-Lader ist im Bereich unter 2000rpm, also wenn die TVG weit geschlossen ist am lautesten. Bei steigender Drehzahl meine ich , das die Frequenz und somit Drehzahl sinkt.

... if you were driving at full speed? That would be quite something .

Are you sure that the perceived drop in pitch isn't simply due to the sound of the loading mechanism being increasingly drowned out by the rising engine noise?

I agree with Jochen, considering the background noise.

BUT: the turbocharger is supposed to work less as well.
Take a look at a typical log of this situation.

When accelerating, the engine initially revs up quickly, often overshooting the desired speed, and then usually less pressure on the accelerator is needed to continue moving forward. So, lower turbo boost despite increasing engine speed - which is fixed by the transmission (manual gearbox).

Similarly, in a Multitronic system, the engine initially revs up to get moving, and then the engine speed decreases even though the vehicle speed (v) increases, simply because the driver no longer wants to accelerate.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

3 Phasen Biber wrote:

I also have a strong vibration in the clutch between 1600-2000 rpm. He then said we would need to reduce the power output, and that would fix it. Hab gehört bei guter SW kommt sowas gar nicht vor?

Correct

Quote:

But 185 hp / 360 Nm surely isn't too much for the ARL

.
If that's even true -> how did the "tuner" even determine those values?

Quote:

Meine Fresse... wie konnte ich nur zum dem tuner gehen. <= ja ich bin eins von diesen Opfern.

Self-awareness is the first step towards improvement .

dieselmartin wrote:

Take a look at a typical log of this situation. When accelerating, it initially revs up excessively and then often requires only slightly less pressure to continue moving forward. So, less turbo boost DESPITE the increasing engine speed.

Okay, if the ears are precisely picking up the end of the overshoot with a decreasing load distance, then the impression of a decreasing pitch for that moment might be accurate.

However, if the load demand is fixed, I don't believe the engine speed can decrease further with increasing motor speed and a constant load demand (and a constant cross-sectional area of the gas passages).

I also wanted to say that the LD (likely "lightness degree" or similar) will not be constant.

No TDI engine I know maintains full pressure in the intake manifold even when you lift your foot off the accelerator.

As soon as you don't want full acceleration, the EDC reduces pressure. And since, in normal driving (in my opinion), you initially press the accelerator and then gradually ease off until you reach a comfortable speed, the LD (presumably referring to "low drive" or similar) will also slowly decrease.

Anyone with VAGCOM and VCDS (VAG-COM Diagnostic System) should be able to reproduce this – if they have a VTG (Variable Turbine Geometry).

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

dieselmartin wrote:

KEIN TDI, den ich kenne, haelt immer vollen Druck im Rohr, auch, wenn man den Fuss lupft.

This is about the worst overvoltage events and the maximum load disturbance (LD), in short: the highest stress on the power supply.
Everything only happens if you don't lift your foot not off the ground .

When it comes to "undefined partial load operations" with a power output ranging from approximately 20% to 70%, anyone can be right if the actual driving profile happens to match their statement.

I was referring to Jochen's "hearing test."
And in my opinion, this is only possible when driving at partial load – that's correct.

Even under full load, an ASV is loud enough that the turbocharger doesn't really add much to the noise.

m