minimum stop | Posts 16+

Hello,

@Reiner
The minimum boost pressure is only reached at full load within the lowest speed range, approximately 1200 to 1500 RPM; above that, the variable turbine geometry (VTG) starts to open again. The factory-set minimum setting takes into account an optimal ratio of boost pressure to exhaust back pressure. If I were to increase the boost pressure by further closing the VTG, the engine's efficiency would be noticeably reduced due to a much higher exhaust back pressure, and the exhaust temperature would also increase (leading to higher component stress). Ideally, for tuning the engine maps, it would be beneficial to measure both the boost pressure and the exhaust back pressure before the turbine. I think some people would be surprised at how high it can be.
I will send the pictures later; I need to disassemble the turbocharger first.
@Ulf
For the GT series, the possible lifting height is greater than the adjustment range.

Best regards, Sepp.

Hi,

Quote:

In my opinion, this also makes more sense than solely relying on the adjustment of the threaded rod to determine the minimum and maximum positions of the VTG.

is standard equipment on at least 2 of the chargers I have, and the 3rd one I bought used, so I can't say anything about its original condition.
There has never been and will never be anything between us and Max-Anschlag. The adjustment lever on mine connects to the receptacle for a miniature set screw, which is not present.

Best regards, Rainer.

Rainer K. wrote:

Quote: In my opinion, this also makes more sense than solely relying on the adjustment of the threaded rod to determine the minimum and maximum positions of the VTG. is standard equipment on at least 2 of the chargers I have, and the 3rd one I bought used, so I can't say anything about its original condition. There has never been and will never be anything between us and Max-Anschlag. The adjustment lever on mine connects to the receptacle for a miniature set screw, which is not present.

Hi Rainer,

OK, one of the limit switches on my enclosure is (I believe) adjusted with a small screw, while the other limit switch is apparently formed "somewhere inside" - I don't remember off the top of my head whether the screw is located at the minimum or maximum limit switch position .

The result, in any case, is that the lifting of the threaded rod on the loader is only about 1 cm (determined manually with the container removed).
This results in a thread adjustment range of approximately 5 mm, independent of the initial preload.

Hello Reiner,

I have some beautiful pictures of the disassembled VTG.
Unfortunately, it is not possible to insert text here.

Do you have any ideas?

Regards,

Sepp.

Hi,

"Add attachment" should do that, at least that's what I always do.

Best regards,

Jan, who is excited about VTG pictures.

Okay, I understand. Please provide the German text you want me to translate into English. I will only provide the translation.

Unfortunately, I am unable to access external websites, including the one you provided. Therefore, I cannot translate the text from the given URL.

If you have web space, simply upload the files.
You can then insert it into the post via

Code:

.

In the pictures taken by Mr. Baumgart, the device also appears to be equipped with a single threaded bolt.

Best regards, Rainer.

Hello Reiner,

Unfortunately, the webspace isn't working, so I'm shamelessly sending you an email with the pictures.

On the left (of one of the last pictures):

Unfortunately, I am unable to access external websites, including the one you provided. Therefore, I cannot translate the text from the given URL.

You can clearly see the pen for the inner maximum stop. In the VNT15 model, it is still a massive component, while in the GT models, it is only a small tension pin.

Regards,

Sepp.

Okay, here are the pictures of Sepp:

However, the charger is a little different in detail compared to the one in my A3...

Am I correct in assuming that the charger in your photograph only has one adjustment screw for setting the maximum charging pressure?

Best regards, Rainer.

Hello,

@Reiner
Thank you very much for your quick help!

The images are numbered, which indicates the sequence of the disassembly process.
Here is a GT15 turbocharger as it is used with the 1.4 TDI-PD engine.
He is, so to speak, the little brother of the GT17 turbocharger from the 1.9 TDI PD engine with 96 kW.
The maximum diameter of the expanded control unit housing is 13.5mm, and the stroke of the control rod is...
The adjustment lever has a stroke of 9mm. The container is pre-loaded with a 1mm preload and requires a vacuum pressure of 600 mbar for the minimum travel.

Regards,

Sepp.

@Reiner,

No, there is only one screw with a lock nut on the bearing housing for the minimum stop.
Please provide the image GARRETT_GT15_02 so I can translate the text within it. Otherwise, only the alignment rod needs to be adjusted; everything else is fixed.

Regards,

Sepp.

Today I have an appointment at Audi, and tomorrow I have an appointment with a tuner.

The result will be published here immediately.

I'm very curious to see who solves the problem and what the ultimate cause turns out to be!
Thank you very much in advance for all the ideas and contributions.


Sure, here's the translation:

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which translates to 'Sincerely' or 'Best regards' in English.

After replacing the mass airflow sensor, the engine runs normally again (without the previous limp-home mode).

The tuner re-examined the chip, optimized the fuel injection amounts and characteristics (curves), and now it runs even better! It sticks better to the gas.

Thank you again to everyone for the helpful tips and tricks.

Sure, here's the translation:

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which translates to 'Sincerely' or 'Best regards' in English.

After a week without any issues, the following occurred:

Increasing distance in the 5th [stage/round/etc.]. Accelerates from 100 km/h to 200 km/h.
at an outside temperature of 5°C.

And again, emergency mode!


Sure, here's the translation:

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which translates to 'Sincerely' or 'Best regards' in English.

Quote:

The tuner re-examined the chip and optimized the fuel injection amounts and characteristic curves, and it runs even better now!

No wonder, after such nonsense.

Okay, if you can't verify the numerous suggestions that have been made here yourself, perhaps we should just drop the topic, right?

This is a self-help forum, and not a place to show off or act like an expert in a workshop or tuning shop.

Best regards, Rainer.

Hi everyone,

Regarding the photos, again:

"So far, I thought, and this has been written multiple times before, that the 1.4 PD-TDI (AMF) engine has a wastegate turbocharger, but the turbocharger in the pictures is definitely a VTG turbocharger."

@Sepp: Is the loader from an AMF, or from a more recent version of the 1.4-liter engine?

Or should it perhaps not have a wastegate after all?

Best regards,

Jan.

Hello,

The 55kW version has a wastegate turbo.
and the 66kW version has the VTG.

Regards,

Sepp.