Wieviel Bar für den VNT17 (GT1749VA)??? | Posts 16+

Hi,

so-so

On Saturday, I will do the renovation .


Regards,
DJ.

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

'Hi,'

Okay, the renovation is finished!

Everything went well - thanks to Thomas and his website .

Question: Should I break in the turbo properly?

Regards,
DJ.

dj1 wrote:

Question: Should I break in the turbocharger?

Yes: no full throttle as long as the engine is cold -> this applies anew for every trip .

Seriously: In my opinion, loaders don't need a warm-up period.

IMO?

Regards,
DJ.

dj1 wrote:

IMO?

In my opinion.

http://www.rhusmann.de/kuerzel/kuer1pke.htm

'Hey Wolfi, thanks for the great website - it's very informative!'

I think I'll break in the turbocharger a little bit (about 300 km).
I'm always a little cautious about that .


Regards,
DJ.

Hello dj1,

How much boost pressure are you running with the VNT 17, and do you experience any overshoot ?

What did you pay for the loader, and was it new ?

Hello dj1,

How much boost pressure are you running with the VNT 17, and do you experience any overshoot ?

What did you pay for the loader, and was it new ?

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

'Hi,'

I'm still using the original software.
I plan to break it in a little bit, as I mentioned before. I can't say anything about whether it tends to over-rev because I'm currently driving very gently.
This weekend, I'll check out what's going on. }

The charger is brand new! These chargers are not cheap! At Volkswagen, it costs around €1400.

Regards,
DJ.

Hi Dennis!

I've now driven 600 kilometers with the new turbocharger.
Absolutely no excessive behavior!
It seals properly at 1 bar.

Regarding performance, I can only say that it seems to be performing similarly to before, as it already ran a bit better with the larger nozzles – I don't really feel much more power here.

I hope that with different software, it will really get to me somehow.

Regards,
DJ.

Hi Daniel,

I'm glad that everything worked out .

Just because some people are driving with pressures of 1.4 to 1.5 bar doesn't mean you should do that. I wouldn't recommend it in your case.
The turbocharger produces 1.3 bar on a 130hp PD engine, but that's not the same as when you run it on your AFN with a larger fuel injection volume, because you can easily exceed 130hp. This means that your exhaust backpressure will also be correspondingly higher, and if that backpressure is much higher than the turbo boost pressure, it will push some of the fresh air back during valve overlap and force more exhaust gases into the combustion chamber. As a result, you lose a significant amount of torque. So, turbo boost isn't everything; the ratio *must* be right.

At a boost pressure of 1.5 bar, my backpressure is 0.6 bar higher. At 1.55 bar, it's at 3.1 bar above atmospheric pressure, and at 1.6 bar, it's approximately 3.8 bar. With the standard software and the VNT15 turbocharger, the backpressure is only about 0.4 bar higher than the boost pressure.
So, try starting with 1.35 bar of boost without any soot; that should be enough for the beginning. Furthermore, this will help protect your components. Based on experience, you can achieve approximately 160 horsepower at 4200 RPM and around 340 Nm of torque at 2100 RPM, mostly without producing soot.
In addition, the charger allows for flexibility to accommodate different environmental conditions.

By the way, this can also be verified using Ulf's data from his dyno run. While the engine sounds like a race car with higher boost pressure (due to excessive backpressure), it actually performs slower.
With proper tuning, the sound is also noticeably richer and more full-bodied, but not nearly as extreme. In its prime, mine achieved a time of 4.2 seconds in Ulf's DZ test.

Here's another small tip. At first, the pressure hoses would constantly crack or at least be pushed off the pipes. As a solution, I replaced those VW hose clamps with proper screw-on clamps and positioned these clamp sleeves around the middle of the hoses so they can't stretch and tear as much. So far, that has worked. On the connections between "normal" pipes and hoses, I roughened the surfaces of the pipes slightly and glued them together using a type of silicone (Elastosil). It's holding up wonderfully so far.

These are my experiences so far.
See you later.
Greetings.
Thomas.

Hi Thomas!

I also think that 1.3 bar is quite sufficient.

At the end of September, I have an appointment with Wendland - I'm really curious to see what my TDI will still be able to do.

Regards,
Daniel.

Hi Daniel,

You're definitely going to do pretty well with that!
Let me know when it's time .


Greetings.
Thomas.

Okay, here's the translation:

1. First of all: you don't need to "break in" the turbocharger.
2. I think the turbocharger can't overspin because it's bigger than the size 15.
3. Overswing or not, if the boost pressure is too high, shouldn't there be an error message about the boost pressure? Please clarify this for me if something is different. Regards, Bernd.

Thomas wrote:

At a boost pressure of 1.5 bar, my back pressure is 0.6 bar higher. At 1.55 bar, it's at 3.1 bar above atmospheric pressure, and at 1.6 bar, it's approximately 3.8 bar. With the standard software and the VNT15 turbocharger, the back pressure is only about 0.4 bar higher than the boost pressure.

Hi Thomas,

"Those are interesting numbers. How did you obtain them? Did you use a pressure sensor in the exhaust manifold?"

What's confusing me again is:

If the back pressure in the exhaust system before the turbocharger is higher than the boost pressure itself, then how can the well-known fault pattern of an open EGR valve with excessive soot formation occur?

In this case, more air must flow through the mass airflow sensor (MAF) than what actually reaches the cylinders -> therefore, a full injection amount (due to the measured air mass) occurs while there is an air leak from the intake manifold to the exhaust manifold. However, this can only "work" as long as the back pressure in the exhaust system is lower than the boost pressure!

Otherwise, exhaust gases are routed back into the intake manifold via the EGR system, which lowers the mass airflow sensor (MAF) reading and may result in a reduction of the fuel injection amount.

Okay, so I installed the GT1749VA today; it took about 2.5 hours because I did everything from the top.
So far, I've noticed that the whistling sound of the old GT15 is gone, and the response feels a bit worse. It doesn't reach its full boost pressure of 1.25 bar (from the chip) until around 2400-2500 RPM, but it maintains that pressure all the way up to over 4000 RPM without dropping off like the old one did after 3500 RPM. I can't understand what some people are saying about the maximum boost being lower than with the GT15. The oil temperature is about 2-4°C lower, at least that's what I noticed on my first drive (~15km).
In the ULF pull-up test, I managed an average of 4.9 seconds (only 3 attempts).


Best regards, Dr. B.

dr_braun wrote:

In the ULF pull-up test, I managed an average of 4.9 seconds (only 3 attempts)

.
And what about the old loader?