Generate loader pressure increase!!!

Hello,
I have the following scenario!
A larger intercooler was installed on an A3 1.9 TDI PD with 130 horsepower.
This larger intercooler causes a pressure drop because it has a larger resonant chamber than before (due to the larger intercooler)!!!
Now I've discovered in this thread /viewtopic.php?t=562&highlight=pin+belegung that you can modify the output signals of the boost pressure sensor (4-pin)!!!
Is it possible to simulate a lower boost pressure by connecting a resistor in series with the boost pressure signal?
This could increase the boost pressure, or...?
This isn't directly about tuning, but rather about reducing the pressure drop caused by the larger intercooler. The goal is simply to achieve a slight and inexpensive increase in boost pressure.
Thank you for your help.

Hi.

Using a resistor in this case can be a bit unreliable.
I would insert a diode into the charge pressure signal line; this practically always reduces the signal by about 0.5 volts and doesn't really pose any problems in terms of adapting to the surrounding impedance level.

If the increase in boost pressure is too high, you can still connect a resistor in parallel with the diode and experiment to find the (kilo)ohm value that results in the desired boost pressure.

Are there different types of diodes with varying voltage ratings?
By how much does the pressure increase if the signal decreases by approximately 0.5 volts?

Animalking wrote:

Are there different types of diodes with varying voltage ratings? By how many bar does the pressure increase when the signal decreases by approximately 0.5 volts?

Hi.

Common silicon general-purpose diodes, such as the 1N4148, all have a forward voltage drop of approximately 0.5 volts.
Special types, such as Schottky diodes, typically provide less voltage drop, usually around 0.3 volts, as far as I know.

A reduction in signal voltage of 0.5 volts can already result in 0.2 or 0.3 bar more pressure - but that is just a rough estimate . It is best to try it out with LDA on board.

Hello,

Whether a larger intercooler was installed or not, shouldn't the engine control unit (ECU) regulate the pressure to a constant level, aside from the initial oscillation behavior of the pressure waves? Or have I misunderstood something?

Georg.

I agree.

You could adjust your VGT (Variable Geometry Turbine) setting. This would cause the turbo to build boost pressure earlier. Am I right about that? It's because the impeller is positioned on the 'fat' side. This would generate pressure more quickly. Even if it then stabilizes.

Sure, here's the translation:

'cu' is a Spanish abbreviation for 'cuánto,' which means 'how much.' It's often used in online communication and text messages to ask for a price or quantity.

Hello,

That idea about using VTG rods might actually be a good one.
Ultimately, this is a control element that directly influences the oscillation behavior of this system. However, things can go completely wrong, especially if an LDA (Laser Doppler Anemometry) is not installed. Possibly, the extreme pressure could cause either a) the turbocharger to seize, or b) only the pressure-leading hose to burst.

What kind of turbocharger is in the 130 PD model? Is there perhaps a performance chart showing pressure, RPM, and flow rate? That would be very interesting.

Best regards, Georg.

Hello.
I believe the 130 PD model has the Garrett 17 turbocharger.
How can the VTG (Variable Turbine Geometry) of the turbocharger be adjusted?
Unfortunately, I don't have a pressure-flow diagram, but it would be interesting to know how many bar (absolute) the charger can handle. If the pressure is too high, the turbocharger could over-rev and break!
P.S.: An LDA is installed!!!

It's a VNT-17. There are no diagrams available for it. I've already asked and searched everywhere. Even Garrett won't release any. The turbocharger can handle a boost pressure of around 1.5 bar.

I wouldn't turn the VGT more than 1/2 to 1 rotation!
The right direction will quickly become clear!

To adjust it, you need to twist the screw that's on the shaft of the VTG using pliers. Please don't ask me which direction to turn it. Also, that screw is secured with Loctite, so you might need to loosen it. And after you're done, I'd recommend re-applying Loctite. You never know!

cu

chris

Thank you for the information!
I need to go find that screw!
Can we get there without having to build anything?
Do you happen to have any idea how much power the turbocharger from a 100 hp PD TDI engine can handle? Is it a Garrett VNT 15?

I think that's a VNT-15. Unfortunately, I don't know the boost pressure. But it gets pretty intense with the VNT-15 at around 1.2 bar. It depends on how you drive. But I don't need to tell you that, do I? You probably can't sleep anyway, lol.

Hello Animalking and Mtw13ve!
Let me ask you all something.
What kind of turbo does the 150 PD actually have? And what is the maximum pressure it can produce? Also, Garret too?

Sure, here's the translation:

'Thank you in advance!'

Sebastiaan

Okay, also auch ein Garrett... aber warum willst du das wissen? Der passt sowieso nicht in dein Auto. Das ist ein VNT-20 Turbo, der auf jeden Fall 1.5 bar Ladedruck erreicht. Soweit ich weiß, ist das der Standard-Ladedruck. 1.8 bar sollten eigentlich möglich sein.

You should know that the larger the turbo, the bigger the turbo lag!
Therefore, if you want to buy a different turbo, get a VNT-17 turbo. If you're lucky, it might even fit directly onto your old manifold. If not, the people at www.centralvwaudi.com will probably be able to make a suitable manifold for you.

Sure, here's the translation:

'cu' is a Spanish abbreviation for 'cuánto,' which means 'how much.' It's often used in online communication and text messages to ask for a price or quantity.

Hehe, I actually drive a 100 hp TDI PD engine that's been chipped!
It's currently at about 1.25 bar!!! I probably shouldn't solder a diode in there, or I'll likely have to start looking for a new turbo! I would also prefer a 150 hp TDI.

Hi,

I've also been thinking about increasing the boost pressure.
I wanted to try that using a voltage divider (potentiometer) and an impedance converter.
(due to signal interference) try.

What do you think about it?

Yes, also Garrett... but why do you want to know? It won't even fit in your car. It's a VNT-20 turbo that definitely achieves 1.5 bar of boost pressure. As far as I know, that's the standard boost pressure. 1.8 bar should actually be possible.

cu

Hello Mtw13ve! I think this one fits perfectly!
I also own a 150 PD GTi! That's why I wanted to know. Thanks for your answer. But how much boost does that thing actually generate?

Best regards, Sebastiaan.