Minimum Stroke Limit | Posts 16+

Hello,

@Reiner
The minimum speed is only reached at full load, typically in the range of 1200 to 1500 RPM, and the variable geometry turbocharger (VTG) starts to open again above that. The factory-set minimum setting takes into account an optimal ratio of boost pressure to exhaust back pressure. If the boost pressure were increased further by 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 stress on components). Ideally, for engine mapping, 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 by how high it can be.
I will send you the pictures later; I need to disassemble the turbocharger first.
@Ulf
For the GT series, the possible lifting height is also greater than the adjustment range.

Best regards, Sepp.

Hi,

Quote:

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

is, but it is standard on at least 2 of the chargers I have, and the 3rd one I bought used, so I cannot say anything about its original condition.
There has never been and will never be anything to do with Max-Anschlag. On my device, the adjustment lever connects to a fitting for a Min-Anschlag adjustment screw, which is not present.

Best regards, Rainer.

Rainer K. wrote:

Quote: In my opinion, this also makes more sense than only depending on the adjustment of the threaded rod to determine the minimum and maximum positions of the VTG. is, but it is standard on at least 2 of the chargers I have, and the 3rd one I bought used, so I cannot say anything about its original condition. There has never been and will never be anything to do with Max-Anschlag. On my device, the adjustment lever goes to the mounting point for a Min-Anschlag adjustment screw, which is not present.

Hi Rainer,

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

The fact is that the result on the loader only allows for approximately 1 cm of travel for the threaded rod (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,

"Attachment hinzufügen" should do that, at least that's what I always do.

Best regards,

Jan, who is excited to see pictures of VTG.

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html

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

Code:

.

In Mr. Baumgart's pictures, the bolt is also only equipped with a single 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 (in one of the last pictures):

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html

The pin for the inner maximum stop is clearly visible. In the VNT15, it is still a solid pin, but 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 photo 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, indicating the sequence of the disassembly process.
Here is a GT15 turbocharger as it is used with the 1.4 TDI PD engine.
He is, in a way, the smaller 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 range of 9mm. The canister is installed with a 1mm preload and requires a vacuum pressure of 600 mbar to reach the minimum pressure.

Regards,

Sepp.

@Reiner,

No, there is only one screw with a lock nut on the bearing housing for the minimum stop.
See image GARRETT_GT15_02. Otherwise, only the adjustment 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 is the translation of the text from German to English:

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which means '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 responds more readily to the throttle.

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

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

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

After a week without any issues, the following occurred:

Accelerating from 100 km/h to 200 km/h in 5th gear.
at an outside temperature of 5°C.

And again, emergency mode!


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

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which means '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.

So, if you can't verify the numerous points that have been raised here yourself, perhaps we should just leave the topic alone, right?

This is a self-help forum, and not a place to show off your knowledge about car repair or tuning.

Best regards, Rainer.

Hi everyone,

Regarding the photos again:

"So far, I thought, and this has been mentioned several 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 using an AMF engine, or a newer 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.