Golf IV TDI Einspritzsüsen wechsel/Testen lassen - nur wo | Posts 16+

@ Rainer, please check your email inbox again - regarding next week .

Rainer K. wrote:

The 5% applies to standard quantities for the 110 model.

That's really all there is to it in this case.
It's amazing what the "popometer" can do with just 5% of the data.
A feeling that the engine is truly unleashed, with a fun-to-drive factor of approximately 5% starting around 2500 rpm (this is my impression of the otherwise stock AFN engine).

Hello everyone,

What actually happens if I install nozzles with the wrong opening pressure?

For example, in an ASV or AHH system, using an 11mm pump and a 220 bar opening pressure, a nozzle with only 195 bar.
The nozzle should open more and close later. Due to the larger flow rate of the pump, the minimum opening pressure should also be higher than with a 10mm pump.
Okay, the EURO3 version is definitely acceptable.

However, it should clearly yield more than 5 to 10%.
That's likely a similar feeling to what Ulf experienced, with an estimated perceived performance increase of around 15%.

@Rainer,

Are there any experiences from the tuning community regarding this?

Best regards, Jochen.

Jochen_145 wrote:

What actually happens if I install nozzles with the wrong opening pressure... a nozzle with only 195 bar? That's probably a similar feeling to what Ulf experienced, which was roughly a 15% perceived increase in performance.

To complement:

My experience relates to standard nozzles 205 / 195 bar -> replacement with 216 / 220 bar.

220 bar opening pressure, while a nozzle only has 195 bar.
However, the result should clearly be more than 5 to 10%.
That's probably a similar feeling to what Ulf experiences, which is roughly a 15% perceived increase in performance.
The additional performance described by Ulf is achieved by changing the diameter of the hole.
Nozzles were formed, not by changing the opening pressure!
This wouldn't be possible because the engine control unit (ECU) detects when the injectors open and close.
and it can react to the reduced opening pressure and adjust the amount accordingly.
It compensates for this, but the quality of the atomization suffers as a result.

Best regards.
Peter.

@ Peter

Not quite.
The high-pressure gas cylinder (STG) receives the first stage, which operates at either 190 bar or 220 bar.
However, the second stage only activates when the pressure reaches approximately 300 bar.

To my knowledge, such a regulation at this level is not possible and will not be implemented.

Therefore, it is called "Spritzbeginn" and not "Hauptstufe" or something like that.

m;

Hi Martin!

I now have the 2003 edition of 'Diesel Distributor Injection Pumps' from Bosch.
checked, as the fuel injectors are also examined in detail there.
'It says there:'
'Der verlängerte Druckbolzen taucht in den Führungsbolzen ein. DThe immersion depth X.
determines the magnetic flux in the receiving coil of the NBS. A movement...
The nozzle needle induces a change in the magnetic flux within the coil.
Speed-dependent signal voltage, which is processed directly in an evaluation circuit within the ECU.
The processing is triggered when a threshold voltage is exceeded, and this serves as the input for the evaluation circuit.
'as a signal to start the injection.'

You can also see two graphs that show the correlation between the physical needle movement and the electrical signal.
Compare the signal from the needle movement sensor.
The threshold voltage seems to be precisely the range that is determined by the movement of the...
The pre-injection (in this case, up to 190 or 220 bar) is what causes this.
The threshold voltage is exceeded only after the initial priming.
'That means the injection control unit (STG) measures the main pressure, which you mentioned, as the start of injection at approximately 300 bar (assuming it's a nozzle-related pressure).'
Okay.

Best regards,
Peter.

PS:
If needed, I would be happy to provide scans of the graphics.