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dj1 Guest
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22-07-2004, 9:27 Subject: VNT17 Turbo: Price & Specs |
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Hello,
I got a new turbocharger, specifically a VNT17 (GT1749VA from a VW Passat PD 130hp), for my Golf 3 (AFN).
Question:
- What boost level are you running on the turbo?
- How much horsepower does this turbo produce as standard?
- How much cash can this turbocharger handle continuously?
Thank you for your answers!
Regards,
DJ.
Translated on 06-08-2026, 2:26.
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SeatLeon Guest
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22-07-2004, 9:37 Subject: VNT17 Turbo: Price & Specs |
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I don't have an answer, but I have another question.
I am running a boost pressure of 1.3 bar with the VNT-15, and experiencing overboosts up to 1.6 bar in the ALH. Is this still within the tolerance range of the turbocharger, or will there be problems in the short or long term?
Translated on 06-08-2026, 2:27.
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ulf Profi-Schrauber

Joined: 04/13/2002 Posts: 11058 Karma: +18 / -0 Location: Saarland 2023 MG ZS Premium Support
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22-07-2004, 10:03 Subject: VNT17 Turbo: Price & Specs |
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SeatLeon wrote: | | I am running a boost pressure of 1.3 bar with the VNT-15, and the overboost reaches up to 1.6 bar in the ALH | . Is this still within the tolerance range of the turbocharger, or will there be problems sooner or later?
I don't have a direct answer, but here's a hint:
The charging capacity is calculated by multiplying the volumetric flow rate by the pressure increase.
As the volumetric flow rate increases with boost pressure, the power output of the turbocharger increases almost quadratically with the boost pressure.
1.3 bar instead of 1 bar results in approximately 60% increased charging capacity under continuous operation.
1.6 bar -> approximately 2.5 times the turbocharger boost pressure for a short period }.
Although this is only somewhat comparable:
What would you say if an ALH engine, without any mechanical modifications, were tuned to produce a continuous power output of 90 horsepower and a short-term peak power output of 225 horsepower? Would there be problems in the long run? Gruß Ulf
_________
MG4 Electric
Translated on 06-08-2026, 2:29.
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eike Guest
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22-07-2004, 11:33 Subject: VNT17 Turbo: Price & Specs |
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Hi there,
I'm assuming that the loader isn't being overloaded due to the torque on its shaft, but rather because of its excessively high rotational speed.
Does anyone have any ideas on how to measure this? Could it possibly be done through acoustic measurement? At low speeds, you can hear the turbocharger whistling. When it starts producing boost, the frequency likely increases into inaudible ranges, which might still be measurable and analyzable using a microphone (piezoelectric sensor).
Perhaps it would be possible to build an analog multiplier that multiplies the engine speed by the boost pressure, thereby estimating the turbocharger speed and displaying it on a gauge. It seems unlikely that it would be feasible to tap into the turbocharger shaft itself and measure its speed...
Then it would be possible to design a tachometer with a 'redline' specifically for a turbocharged engine.
For a boost pressure of 1.3 bar, you need less turbocharger speed at 2000 RPM than at 3800 RPM, which means you can optimize the turbo's performance across all engine speeds.
Does anyone have any ideas on how to implement a tachometer for a turbocharger?
Greetings.
Eike.
Translated on 06-08-2026, 2:32.
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dj1 Guest
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22-07-2004, 14:03 Subject: VNT17 Turbo: Price & Specs |
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Is anyone not using the turbo?
Hello?
Translated on 06-08-2026, 2:34.
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ulf Profi-Schrauber

Joined: 04/13/2002 Posts: 11058 Karma: +18 / -0 Location: Saarland 2023 MG ZS Premium Support
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22-07-2004, 14:39 Subject: VNT17 Turbo: Price & Specs |
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eike wrote: | | For a charging pressure of 1.3 bar, you need less turbocharger speed at 2000 RPM than at 3800 RPM, which means you can optimally utilize the turbocharger in every speed range. |
That's probably less true than you might initially think.
In simplified terms, the characteristic curves of a blower indicate that while the blower speed always increases with the required pressure, it is almost independent of the mass flow rate within a large operating range.
In other words: 1 bar of boost at 2000 engine RPM means nearly the same turbocharger speed as 1 bar of boost at 4000 engine RPM, provided that the turbocharger is well-matched to the engine.
-> The lower the gas flow rate, the more the turbocharger "spins out of control" (figuratively speaking), and the lower its efficiency becomes.
Please search for information about charging curves and related topics here.
You'll find corresponding images somewhere that will help you understand. Gruß Ulf
_________
MG4 Electric
Translated on 06-08-2026, 2:36.
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dennis79 Guest
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23-07-2004, 16:41 Subject: VNT17 Turbo: Price & Specs |
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Der GT1749VA wird in nahezu jedem 130PS PD Motor verbaut. You only need to.
Make sure it doesn't have a pre-attached manifold. (1.3 bar standard pressure).
1.5 bar is easily achievable  .
I drive one myself in my AFN  .
Regards,
Dennis.
Translated on 06-08-2026, 2:38.
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dj1 Guest
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23-07-2004, 17:57 Subject: VNT17 Turbo: Price & Specs |
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Der GT1749VA wird in nahezu jedem 130PS PD Motor verbaut. You only need to.
Make sure it doesn't have a pre-attached manifold. (1.3 bar standard pressure).
1.5 bar is easily achievable  .
I drive one myself in my AFN  .
Regards,
Dennis
Hi Dennis,
'Mine doesn't have a manifold!'
I'm going to install it tomorrow.
Can you tell me a little more about your renovation?
Where did you have your engine tuned?
How long have you been driving the Turbo?
Satisfied?
Sure, here is the translation of the text from German to English:
'Etc...'
Regards,
DJ.
Translated on 06-08-2026, 2:39.
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dr_braun Guest
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23-07-2004, 19:21 Subject: VNT17 Turbo: Price & Specs |
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@DJ1:
'Could you possibly take some pictures during the conversion? That would be great because I'm planning to do something similar soon. As far as I know, the oil lines should fit, but the intake hose will need to be modified. Does the compressor fitting connect to the AFN pressure pipes?'
Best regards, Sebastian.
Translated on 06-08-2026, 2:41.
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dieselschrauber Administrator


Joined: 04/12/2002 Posts: 18086 Karma: +797 / -0 Location: St.Gallen 2018 Volkswagen T6 
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24-07-2004, 16:47 Subject: VNT17 Turbo: Price & Specs |
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dr_braun wrote: | @DJ1:
..could you possibly take some pictures during the conversion? That would be great because I want to do it soon too. The oil lines should fit, but as far as I know, the intake hose needs to be modified. Does the connection of the supercharger fit the AFN pressure pipes? |
Hello,
Okay - everything matches perfectly 1:1, except the compressor output, which has a clip connector.
Solution: Take the connection adapter for the charge pressure hose from this shop here.
Best regards, Rainer.
Translated on 06-08-2026, 2:43.
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dennis79 Guest
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24-07-2004, 17:42 Subject: VNT17 Turbo: Price & Specs |
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Hello Dj1,
I drove the VNT17 for a while with 1.4 bar -- I didn't have any problems with it  .
How much boost pressure do you want to run  ?
The pressure build-up takes longer in the lower RPM range, but you experience almost no turbo lag (overshoot). This is because the larger turbocharger has a bigger compressor housing – the AFN engine uses the smaller one.
I've temporarily removed the chip because I installed nozzles with a size of 0.216.
I did not personally carry out the renovation  .
Keep us updated.
Translated on 06-08-2026, 2:45.
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dj1 Guest
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24-07-2004, 19:43 Subject: VNT17 Turbo: Price & Specs |
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Hello Dennis79,
Thank you for your reply!
I once read that you don't necessarily need extremely high boost pressure to achieve good performance.
I think around 1.3 bar of boost pressure should be sufficient for 150-160 horsepower.
I also have the large nozzles installed  .
Once the turbo is installed, I'll definitely need to do some tuning.
Regards,
DJ.
P.S.: How long have you had the turbo installed?
Translated on 06-08-2026, 2:47.
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Garret Guest
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25-07-2004, 10:29 Subject: VNT17 Turbo: Price & Specs |
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Here's an installation guide for the VNT 17 turbocharger into an AFN engine (Passat).
from the Manuel A4 TDI manual.
Installation instructions
Perhaps this will help.
Translated on 06-08-2026, 2:48.
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dennis79 Guest
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25-07-2004, 14:50 Subject: VNT17 Turbo: Price & Specs |
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Hello dj1,
What kind of car do you drive, and what is your fuel efficiency (miles per gallon)?
What boost pressure are you running right now, and is your clutch slipping?
Did yours have the standard software and the 0.216 nozzles installed? (Mine has a little bit of stringing, but not much – I can't shake the suspicion that there might be a slight leak in my pressure hose).
Translated on 06-08-2026, 2:49.
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dj1 Guest
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25-07-2004, 18:15 Subject: VNT17 Turbo: Price & Specs |
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Hi Dennis,
It's all in the first post!
'Emm, what is DZR?'
Boost pressure is 1.0 bar.
With the larger nozzles, there's a little more soot, but it's really minimal!
Translated on 06-08-2026, 2:50.
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dennis79 Guest
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27-07-2004, 16:30 Subject: VNT17 Turbo: Price & Specs |
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DZR = Beschleunigung von 2000 - 4000 Rpm im 3. Gang
Do you already have the turbo installed  ?
Translated on 06-08-2026, 2:51.
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