Golf 5 TDI: Speedometer Error - Only 215 km/h?

Hi,

The car with the BKD engine and *** chip isn't performing very well. It only reaches 215 km/h according to the speedometer while flooring it, which is quite disappointing.

What other MLOps metrics (besides 10 and 11) should be tracked to obtain good, helpful results?
Please include the diagrams tomorrow.

@vagtuning:

What RPM does the engine reach at its maximum speed?

Please log the fuel injection amounts (driver request, torque limitation, soot threshold) across the entire RPM range under full load.

Regards,
Alex.

I need to figure out which channel that is.

I'll try logging values of 10 and 11, and then see what happens.

The RPM is still around 1200 RPM until it reaches the normal operating limit, so there's still a little bit of headroom. Adding just 10-15 more horsepower wouldn't have raised any eyebrows, but every 8L engine with a 130 HP 1.9L configuration already exceeds that limit.

Hi,
Could it be that your tuner forgot to remove the speed limiter?

Best regards, Rudi.

The speed is currently around 1200 RPM, which is still below the normal operating range...

just as a heads-up:

The no-load speed and the speed at which maximum power is achieved have absolutely nothing in common!

One is a safety limit, and the other is primarily determined by physics (combustion speed, earliest possible injection timing, etc.).

Besides that, the gear ratio still depends on the vehicle's characteristics (weight, drag coefficient, etc.).

see also https://community.dieselschrauber.org/en/viewtopic.php?t=7819 for suggestions...


CU Gremlin.

Okay, but we agree that a car with 170 horsepower, according to the dashboard, should be able to achieve more than 215 km/h, right?

'If you subtract the deviation, then the result is quite disappointing. Especially because you have to let a) every 130 hp car and even today's regular 3-series GTI (115 hp) pass you on the highway... I didn't think the 3-series would be able to keep up, but it did... it just managed to stay behind, clinging on, and then at the exit, it signaled me to ask if it was a 16V. No, it was just a normal 2.0L 115 hp 3-series GTI.'

That's really terrible! / That's absolutely awful!

Hi,

If your car reaches its maximum speed (Vmax) without any modifications, meaning it's already operating at or beyond its peak power output (Pmax), then even if you tune it extensively, the car won't become significantly faster, or possibly not faster at all.

Assuming a base idle speed of 5200 RPM, you'd have 4000 RPM at maximum velocity, and that's usually also the point where peak power is reached. It's unlikely to get much more than that.

Best regards,

January.

Okay..., but we agree that a car with 170 horsepower, according to the speedometer, should be able to achieve more than 215 km/h, right??


Who says that the engine has 170 horsepower?

Company A.B.T says that he should have it at least.
Here are the logs. Maybe someone can explain how to create a graph from them. I've been trying for an hour now and haven't managed to get anything really good.

http://vagtuning.piranho.com/LOG-01-008-004-dreh.CSV
http://vagtuning.piranho.com/LOG-01-010-011-xxx.CSV

Okay, here we go.

So, that's actually quite easy to achieve.
Using Excel is already a good idea, vagtuning.
Instead of opening the log file directly, open Excel, go to "Import Data," specify a comma (,) as the separator, and you'll get a large number of columns. The rest should be quite simple from there.

P.S.: I'm not an expert when it comes to these values, but in my opinion, it seems strange that approximately 410 Nm of torque is required at around 4000 RPM, while the torque limit is set at 390 Nm and the soot reduction limit is below 300 Nm.

However, the accuracy of this statement is not guaranteed, as I am not familiar with the subject matter. Nevertheless, if the threshold is significantly lower than what is required, it might be possible for problems to arise. However, I believe that this could also make sense in the higher RPM range, but it shouldn't be the case in the mid-range.

I only looked at the first log entry. However, wouldn't it be interesting to learn more about the amount being injected?

I looked at a couple of other logs from the forum, and in those cases, the emission limits were always higher than the torque limits.

Here's the translation:

'In our case, as mentioned before, the smoke limit is always significantly below the torque limit. Does this make a difference? Is that correct? And can this limitation have the effect described?'

As far as I can tell, the boost pressure and air mass readings appear to be completely normal.

vagtuning wrote:

In our case, as mentioned before, the smoke limitation is always significantly below the torque limitation. Does this make a difference? Is that correct? And can this limitation have the described effect?

Well, if it were a standard VP or a 2V-PD, I would say "Bingo, something's wrong here, so keep investigating in that direction."

However, I am not familiar with the control strategy of the 4V TDIs, let alone your tuner's specific approach. Therefore, all I can say is "it might be possible..."

I can't see the logs because the session was automatically terminated for security reasons.

It was only possible as long as Web.de still thought you were logged in... After 1 hour, it stopped working.

I've changed the location, so it should work now.

Hi,

I looked up the specifications for the engine, and here's what I found:

008 Limiting factor 1.
Coolant temperature minimum 75°C:
Engine speed.
Idle speed: 810...940 /min.
At full load: 2800...3200 /minute.
2) Requested torque (throttle).
Idling: -5...0 Nm.
At full load: 350-420 Nm.
3) Torque limitation.
Idling: 100...200 Nm.
At full load: 350-420 Nm.
4) Smoking restrictions.
Idling: 100...200 Nm.
At full load: >= Torque limitation (see field 3).

And as far as I can see, the smoke limit is always below all other values.
Now for the million-dollar question:
What's the reason for it? / What's causing this? / Why is that happening?
- The boost pressure/air mass seems to be good... But is the software calibration in the engine control unit correct?