Überschwinger 150 PS (ARL) | Posts 48+

ulf wrote:

Aber wenn der LD eingeregelt ist, kann die Laderdrehzahl bei steigender Motordrehzahl und konstantem LD (und konstantem Querschnitt der Gaswege) IMO nicht noch weiter absinken.

Hi there,

At this point, I'd like to chime in as well.

The compressor of the turbocharger essentially only works by displacing air. The air inside the turbine, due to its high flow velocity, is so inert that it's flung outwards past the blades.
There is some influence visible in all the data points.
The higher the rotational speed, the greater the air's moment of inertia --> resulting in more airflow relative to the rotational speed. However, once the turbocharger kicks in, these factors become less significant. It would be worthwhile to examine a diagram of a pure compressor (compressor * rotational speed) in more detail.

Ultimately, the rotational speed is the primary factor influencing the flow rate. For example, a compressor running at its maximum flow rate will still achieve nearly half of its rated flow rate when operating at only 50% of that speed. Considering these circumstances, the rotational speed of the drive mechanism must increase as the demand for flow increases, because the amount of air displaced by the compressor is ultimately determined by the rotational speed.
And since both Waster and VNT systems operate on the same principle, because the compressors are static.

"I haven't heard the turbo properly in a long time. Even at 20 km/h in second gear, it roars like a wild animal. When it reaches its target boost pressure of 950 mbar at 1750 rpm, you only hear a hissing sound, probably because the pressurized columns of gas and the rapidly drawn-in air significantly reduce the noise."

Quote:

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

Quote:

In a variable geometry turbine (VTG), the impeller 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. Die geschlossenstellung findest du jedoch nur bei niedrigen Drehzahlen, somit können hohe Laderdrehzahlen nur bei niedirgen Motordrehzahlen entstehen.

The characteristic curve is correct; it's a COMPRESSOR CHARACTERISTIC CURVE and applies to compressors. It doesn't matter whether the compressor is driven by an electric motor, a hamster, a wastegate turbine, or a variable geometry turbine.

The charging pressure, which is the compressor pressure (represented by the Y-axis in the diagram), is regulated through an intervention in the "drive unit" of the compressor. Increasing the drive power also increases the compressor speed. A higher compressor speed generates a higher pressure ratio, depending on the volumetric flow rate.
Changing the volumetric flow rate with a dosing pump while maintaining a constant speed would also change the pressure. (Closing the valve would increase the pressure.)

The compressor and its performance characteristics are not initially concerned with the specific VTG setting or steroid dosage used to provide this drive power from the turbine/hamster; that is primarily the responsibility of the turbine/hamster itself, which has its own unique TURBINE PERFORMANCE CURVE.

"Ulf Beispiel" (which translates to "VTG stuck/Hamster drug rampage") simply means that the compressor's drive shaft is positioned too high, resulting in an excessively high compressor speed and, consequently, more boost pressure than desired.
The question is, what is the limiting factor? It could be either the compressor (pump/stopper) or the turbine/hamster.

To assess the effectiveness of the emergency mode, it's crucial to first determine WHAT the original equipment manufacturer (OEM) primarily intends to protect with this feature.

Turbine, compressor = supercharger.
or the engine?


In the compressor characteristic curve, you can see that for a given speed (constant speed), the pressure decreases as the flow rate increases. Therefore, if I want to maintain the same pressure at a higher flow rate, I need to increase the compressor's rotational speed! (This does NOT mean I have to use a variable geometry turbine; VTG is related to the turbine).

By the way, the red line represents the pressure ratio (let's say boost pressure) at full load with a functioning turbocharger control system on the turbine side.
After the initial start-up (flow rate at 0.03), it spins just above 140,000 RPM. At the end of the flow rate range (maximum motor speed), the boost pressure is still approximately 1.8 bar due to the control system, but the compressor is now spinning over 160,000 RPM.

Jochen, think about it before you act .

"A turbine or compressor; the turbine drives the compressor, and no, the ratio is not 1:1."

Malte1408 wrote:

die Turbine treibt den Verdichter an und nein die Übersetzung ist nicht 1.

but

@ Ulf

It should probably be a test bench file .

Meanwhile, I've heard more about the reputation of the tuner .

I'm going to check and verschandeln my laser disc system tomorrow, and then I'll look into getting some new software for it.

3 Phasen Biber wrote:

Malte1408 wrote: die Turbine treibt den Verdichter an und nein die Übersetzung ist nicht 1. but

It was more likely to be seen with a , and the mechanical translation is already 1. The actual translation is determined by the "pitch" (I can't think of another word right now) or diameter of the turbine and compressor.

Hi.

Today I measured my boost pressure using OBD tuning and also with my boost gauge. I'm seeing the same peak pressures as when the chip is activated, but it seems like the boost values read by OBD are even slightly lower than what my gauge shows. I think I might need to readjust my boost gauge. I'll compare it to the readings in VAG-COM, which I believe are quite accurate.

Sure, here is the translation of the text from German to English:

"MFG" stands for "Mit freundlichen Grüßen," which translates to "Sincerely" or "Best regards" in English. It is a common way to end a formal letter or email.

In dem Verdichterkennfeld erkennt man übrigens, anhand der Linien GLEICHER Drehzahl (=konst. Drehzahl), das mit steigendem Durchsatz der Druck absinkt. Somit muss ich wenn ich auch bei höherem Durchsatz den Druck halten will, die Verdichterdrehzahl erhöhen!


Perhaps one should consider the topic of 'overspeeding' from a speed-oriented perspective and, in this context, seek advice from someone knowledgeable about turbocharger KV (kilovolts).

The turbocharger only over-revs when it needs to deliver a flow rate that exceeds its capacity.
Sprich, bei 4000rpm werden z.B. 0,2bar Überschwinger sicherlich problematisch. Bei 2000rpm muss er bei gleichem Ladedruck aber nur die Hälfte des Volumentroms bewältigen. Somit dürfte es nach dem pi x Auge Prinzip erst ab 0,4bar Überschwinger problematisch werden. Hier wird viel ehr die Pumpgrenze ein Problem darstellen.

Okay, so if you're right now, then my own considerations from yesterday were actually correct. What this also means, however, is that Rainer and Ulf unnecessarily worried themselves and did the work of re-calculating the input VAT for the Turbo.

As I mentioned earlier, the turbocharger speed would not reach critical levels at 2000 rpm because the amount of air being forced in is not large enough, but the variable geometry turbine (VTG) has sufficient reserves to redirect the exhaust gas flow 'around' the turbine.



Jochen, think about it before you decide.

Thank you, same to you.
As I would like to emphasize once again, the statements made this morning were not my own.


Best regards,

Quote:

Was andererseits aber auch heisst, dass sich Rainer und Ulf unnötig einen Kopf und die Arbeit gemacht haben, die Vorsteuer-KV des Turbos neu abzustimmen.

Well, I certainly wouldn't say that!

Is a lower loader speed always better?

2) A large deviation from the setpoint due to a poorly designed pre-control stage does not make the controller's job easier later on, and it will not improve the quality of the control.

3) Is there also a head gasket?

I'm not really into tuning, but I would say that *not* adjusting the pre-gain is just plain wrong.

Quote:

The turbocharger speed would not reach critical levels at 2000 rpm, as I wrote, because the amount of air being forced in is not large enough, but the variable geometry turbine (VTG) has sufficient reserves to "redirect" the exhaust gas flow around the turbine.

Perhaps, as I hinted at in my previous post, it's not just about the charger.

Furthermore, a regulation that works well is something to be strived for, and not some haphazard system where things barely avoid breaking.

Jochen_145 wrote:

So, so if you are right now, then my own considerations from yesterday were actually correct. What this also means, however, is that Rainer and Ulf unnecessarily worried themselves and did the work of re-calculating the input VAT for the Turbo.

Hm, "our" work could only be for free if what is here

Jochen_145 wrote:

every overachiever is already a compromise on long-term durability. The more I overcharge it, the sooner my charger will fail. This also applies to the series! Therefore, each increase in LD (Load Dump) through tuning shortens the lifespan, as the design life is only specified for the standard configuration. (An exception to this would be the 90HP VTG-TDI, ALH?).

would be incorrect.

Given that the speed curves in the compressor's control unit show a slightly decreasing trend, it is my opinion that the turbochargers actually still have some speed reserves available. However, the original equipment manufacturer (OEM) does not utilize these reserves to prioritize engine efficiency (avoiding unnecessarily high boost pressure) or to protect the powertrain from excessive torque.

In the Pmax range, however, I assume that Jochen's aforementioned quote is correct, meaning that when tuning, higher LD peaks than those found in the stock configuration should definitely be avoided.

Well, I certainly wouldn't say that!

Is a lower loader speed always better?

2) A large deviation from the setpoint due to a poorly designed pre-control stage does not make the controller's job easier later on, and it will not improve the quality of the control.

3) Is there also a head gasket?


Okay, but that sounds like you're just trying to put a positive spin on things regarding Ulf and Rainer.

Here's the translation:

'1) According to your statements, the maximum impeller speed occurs at maximum load and maximum engine speed (e.g., rated power speed). Therefore, you should reduce the maximum boost pressure at the rated power speed, rather than reducing the overboost, as this will result in a lower impeller speed (as mentioned above, due to reduced air volume flow). However, the turbocharger is designed for this operating condition in its standard configuration.'

'My controller is fast enough (less than 3 seconds) to catch the overshoot. If the deviation is too large, it will be corrected automatically. I don't see this as a problem.'

The injection timing is set back by such a significant amount that, from the perspective of the cylinder head gasket, any over-advance at around 2000 rpm would likely have little effect.
At 4000 rpm, it looks quite different...

Ich interessiere mich eigentlich nicht für Tuning, aber ich würde sagen; die Vorsteuerung NICHT anpassen, ist FUSCH!

Wenn du wüssest, wie die Vorsteuerung in vielen Fällen angepasst wird, kann man leider nur von Verschlimmbesserung sprechen. Da ist es vielfach besser, wenn man die Vorsteuerung nicht anfasst. Das richtige Abstimmen ist seeehr viel Arbeit. FSure, here's the translation:

'Hey Ulf...'
Very few tuners invest in that.


Außderm ist eine Regelung die gut funktioniert anstrebenswert und nicht irgend ein Murks wo die Teile 'gerade so' nicht kaputt gehen...

The regulation itself isn't being touched; it's solely about the pre-calculation.

Within the Pmax range, however, I assume that Jochen's aforementioned quote is correct, meaning that when tuning, higher LD peaks than those in the stock configuration should definitely be avoided in that area.

Here, it's probably quite clear.

Problematisch ist, daher ist ja der Grundansatz die Überschwinger zu betrachten vollkommen korrekt, die Überschwinger wirklich drehzahlabhängig einzusetzen.
The best solution lies right here, and it will also require recalibrating the VAT input tax field.

Best regards, Jochen.

Jochen_145 wrote:

Quote: Außderm ist eine Regelung die gut funktioniert anstrebenswert und nicht irgend ein Murks wo die Teile "gerade so" nicht kaputt gehen... The regulation itself is not being touched; it's solely about the pre-funding

.
...which has a significant impact on the engine's performance when accelerating fully. Therefore, from the user's perspective, "the tuning" is definitely something that is adjusted, and that's why I think this wording is generally okay (as long as it doesn't delve into highly technical aspects).

back to the topic!

I checked my boost pressure system.

In the MBW 11 system, with the default settings, the pressure cylinder moves to both end positions within one second.

The VTG (variable turbine geometry) is very smooth and the hose up to the boost pressure control valve is completely leak-proof.

Surely it can only be this humble software now, right?

Assuming the control valve is not sluggish and the rest of the hose connections are tight!

Hello,

ist der KAT (Innenkörper) noch da? Macht immer besonders Spaß derart getunte Kisten abzustimmen, wenn sich genau das erst während der Abstimmung rausstellt. Dann darf man gleich mal ne Stunde extra rechnen und ne schöne Delle ins KF zaubern.

Best regards, Rainer.

No knocking! Kat seems to be in great shape.

I just spoke with my VW master mechanic, and he said that the turbocharger boost control valve can sometimes be a bit slow to respond.

So, should I cross-check it with the control valve next to it?

3 Phasen Biber wrote:

I just spoke with my VW master mechanic, and he said that the turbocharger boost control valve can sometimes be a bit slow. So, should I cross-check it with the control valve next to it?!

Why not? Practice makes perfect.

In my thread about "evaluating boost pressure," I posted a video (unfortunately, the quality is quite poor) showing how an N75 valve reacts to basic settings on control module 004.

The gauge, which measures pressure from -1 to 0 bar relative, suddenly jumped from 0 to -800 millibars and back again – faster than the camera could record it.

/viewtopic.php?t=12864&highlight=asv+assessment

inside the Leon.zip file.
Okay, I'm ready. Please provide the German text you want me to translate into English. I will only give you the translation.