Turbocharger Tuning: How To & Guide

Hi everyone, I removed the turbocharger from my Seat Ibiza (81 kW AFN engine) yesterday.
I'm experiencing a lack of power in the lower RPM range. After taking everything apart, I noticed that the wastegate actuator's end stop is misaligned because the lock nut has come loose. According to the specifications, it should accelerate from 0-100 km/h in 10.2 seconds, but I'm getting around 12 or more seconds. I already tried swapping the mass airflow sensor (MAF), but that didn't help. I can almost rule out any other mechanical defects.


My question now to the experts on forced-air ventilation of tractor engines:
How do I restore the original VTG coupling system to my tractor?
What happens if the detachment starts too early or too late?
Could the vacuum sensor possibly be damaged?

I replaced the pressure transducer for the VTG a few weeks ago, but it didn't help!
I have the impression that the charging pressure builds up too slowly. At least, that's what I can tell from a manual LDA (likely referring to a device or system). Does anyone have any advice for me on this matter, besides using the search function?

Thank you very much in advance.

Hi Daniel,

Perhaps the following link will be helpful:
http://www.turbolader.com/vnt/vnt.htm

Adjusting the impeller properly will be difficult; I fear you can only roughly adjust the turbocharger so that the blades don't touch and there is some "clearance" left.
I would then carefully adjust the remaining settings using a boost pressure gauge and countless test drives.
While driving, also check the duty cycle of the magnetic valve used for turbocharger pressure regulation; this will usually be the first sign if something is going wrong.

Best regards, Rainer.

Thank you for the tip.
The aspect ratio thing might be a bit tricky; unfortunately, I only have a fixed computer in the garage.
I haven't been able to bring myself to buy a really cheap laptop yet.

Should the cutting edge be angled further outwards, or should it start cutting earlier?

Hi,

g1om wrote:

Should the cutting edge be angled further outwards or should it start its cut earlier?

Hmm, what can I say... I don't know how the feedback loop is behaving right now.
While too much boost pressure in a particular "operating mode" might improve responsiveness, it likely won't be beneficial for fuel consumption due to excessively high or "unnecessary" boost pressure during idle and partial load conditions.

"Addition: Of course, the boost pressure hardly changes in the regulated state as long as the control system can generally still function. Unfortunately, with a different 'minimum boost pressure' setting, the actual boost pressure in partial load conditions changes slightly."

Best regards, Rainer.

Hi,

I've found that the best results are achieved when the VTG rod is as long as possible, essentially reaching the innermost stop.

Quote:

According to the list, it should accelerate from 0-100 km/h in 10.2 seconds, whereas I usually need around 12 seconds or more.

It can depend on the day and, above all, on the equipment. It doesn't always have to be a defect. I don't know what your Ibiza is carrying around, but even 100 kilograms more or less makes a big difference.
There are headwinds during measurement, the track isn't level, rollers instead of wheels – there are so many variables.

Have you checked the error memory yet? Does it reach the maximum speed?
Without a laptop and a VAG-Com interface, it's naturally difficult to say anything definitive about it.
Normally, when I encounter something like this, I perform a diagnostic run and record VAG COM values such as boost pressure, fuel injection quantity, etc. This often quickly reveals where the problem lies.

Greetings.
Thomas.

Okay, now I have everything completely and precisely organized. I put in the effort to organize my notebook, and I've logged two things there, each with values between 2,000 and 4,000.
I've also noticed that I can't reach the maximum speed anymore, no matter what setting I use on the charger. At 180 km/h downhill with a tailwind, it stops!
on a straight track, something over 170 [units - e.g., kilometers per hour].
The tractor is registered with an unbelievable top speed of 193 km/h.


Regarding that issue, it might be related to the fuel injectors. I took my car to a Bosch service center last week, and they adjusted the injection pressure back to 190 bar.
At least one thing has improved!!! He doesn't smoke anymore *lol*.

Since I'm not an expert in Excel, here are my logs.



1. 16, 2205, 850.0, 1040.0, 4.8, 0.36, 1974, 45.2, 41.6, 44.0, 0.76, 2079, 41.6, 12.09, 45.0
2.36, 2520, 850.0, 870.0, 4.8, 1.56, 2310, 44.8, 41.6, 44.0, 1.96, 2415, 41.4, 14.04, 44.6
3.56,2856,850.0,880.0,4.8,2.76,2646,44.4,41.4,40.6,3.16,2751,41.6,15.99,44.2
4.76, 3171, 850.0, 940.0, 4.8, 3.96, 2961, 43.8, 41.8, 43.6, 4.36, 3066, 41.8, 17.94, 43.6
6.07, 3486, 850.0, 925.0, 4.8, 5.16, 3297, 43.4, 41.0, 43.6, 5.56, 3381, 40.8, 19.11, 43.4
7.30,3822,850.0,890.0,4.8,6.48,3612,43.2,40.2,42.0,6.90,3717,40.0,20.67,43.0
8.50,4074,850.0,830.0,4.8,7.69,3906,42.8,39.4,42.0,8.10,3990,39.0,21.84,42.8


'Wow, this looks strange. Well, if you can somehow still make use of it, please let me know, or just write to me if you need it in any other way.'

Sure, thanks in advance. Thx.

Hi...

You're a hero... if you had copied the first few lines of the log file, we could see which column represents what. However, based on what I see here, it doesn't seem to be showing boost pressure; rather, it appears to be displaying air mass and injection volumes.

Best regards, Rainer.

'Hubs, sorry, I just realized myself. Now we should have everything, but it still looks weird to me.'


Group A: ,'003,,,,Group B: ,'008,,,,Group C: ,'015,,
'Engine speed, MAF (specified), MAF (actual), EGR duty cycle', 'Engine speed, Injector quantity, Injector quantity, Injector quantity', 'Engine speed, Injector quantity (actual), Fuel consumption, Injector quantity requested'.
TIME,861-945,240-340,240-340,4-84,TIME,,?,?,?,TIME,,,,(accelerator)
MARKER, STAMP, /min, mg/R, mg/R, %, STAMP, /min, mg/R, mg/R, mg/R, STAMP, /min, mg/R, l/h, mg/R.
1. 16, 2205, 850.0, 1040.0, 4.8, 0.36, 1974, 45.2, 41.6, 44.0, 0.76, 2079, 41.6, 12.09, 45.0
2.36, 2520, 850.0, 870.0, 4.8, 1.56, 2310, 44.8, 41.6, 44.0, 1.96, 2415, 41.4, 14.04, 44.6
3.56,2856,850.0,880.0,4.8,2.76,2646,44.4,41.4,40.6,3.16,2751,41.6,15.99,44.2
4.76, 3171, 850.0, 940.0, 4.8, 3.96, 2961, 43.8, 41.8, 43.6, 4.36, 3066, 41.8, 17.94, 43.6
6.07, 3486, 850.0, 925.0, 4.8, 5.16, 3297, 43.4, 41.0, 43.6, 5.56, 3381, 40.8, 19.11, 43.4
7.30,3822,850.0,890.0,4.8,6.48,3612,43.2,40.2,42.0,6.90,3717,40.0,20.67,43.0
8.50, 4074, 850.0, 830.0, 4.8, 7.69, 3906, 42.8, 39.4, 42.0, 8.10, 3990, 39.0, 21.84, 42.8

Quote:

However, based on what I'm seeing here, it doesn't look like there's an issue with boost pressure; rather, it seems more related to air mass and fuel injection volumes.

Again...