Injection Timing: Funding Start Information

Hello,
I've already searched through the technical articles and Google, but there are still some unanswered questions.

The start of fuel injection is visible using VAG-COM, and small adjustments can also be made dynamically. In principle, the start of fuel injection is equivalent to the injection timing, but they are not the same thing.
I can logically understand the injection timing, but what units and logic are used for the start of fuel delivery?
If you read a value of, for example, 55 for the start of boost using VAG-COM, can you then logically deduce what that value means?

Unfortunately, I couldn't find anywhere that explains how the start of fuel injection correlates with the injection timing. For example, if 55 is the optimum value, does 65 represent an earlier start of fuel injection (and thus an earlier injection timing), or is it the other way around?

Is there a way to convert the start of injection into the injection timing (e.g., vOT)?

Is there a database of charts or diagrams available for the optimal injection timing start for an SDI (ASY) engine in diagnostic mode (increased RPM), or for other TDIs? I have a chart for TDI-Graph for my 2.5 TDI (AEL), but I can't find anything for the SDI.
Best regards,
Pappl.

The difference between the start of material feeding and the start of spraying lies solely in the inertia of the pressure build-up, or the speed at which the pressure propagates from the pump to the nozzles.
The start of injection is measured using the NHG (Needle Lift Gauge), while the start of fuel delivery is adjusted or "set" at the pump.

christians wrote:

The difference between the start of injection and the start of spraying lies solely in the inertia of the pressure build-up, or the speed at which the pressure propagates from the pump to the nozzles. The start of injection is measured using the NHG, while the start of fuel delivery is adjusted or "set" at the pump.

Therefore, there is a difference between the start of the injection and the start of the spraying process, but this difference is constant and can be considered a fixed factor.
However, the values that can be read out via OBD are, unfortunately, just numbers to me without any further context or logic.
Many people know that the start of the measurement process should be set to the desired x and y values, and they simply set those values and that's it.
It would be interesting to know what these numbers mean. " color="red">Bitte keine Links zu externen Dateihostern! a) nerven die zusätzlich notwendigen Klicks, b) Wartezeit, Werbebanner/Werbepopups und notwendige Registrierungen, c) ist nach einiger Zeit die Datei weg und das Thema für andere Leser nutzlos!

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PAPPL wrote:

Many people know that the start of the feed should be set in measurement blocks in the x and y target ranges, and they set it accordingly, and that's it. It would be interesting to know what these numbers mean.

For example, the "plain text data" in the MWB4 should, in my opinion, be self-explanatory.
The timing checker also uses SB target and actual values, but as raw data on the diagnostic system's own 8-bit scale from 0 to 255.

Regarding the speed, it's relatively simple to explain: Every plaintext speed value (rpm) is divisible by 21. Also, the speed scale only has 256 different values, with the largest value being 255 x 21 = 5355 rpm.
Test question: A raw speed value of 48 therefore corresponds to how many rpm?

In the case of SB, the conversion is a bit more mysterious because the plaintext scale ranges from somewhere before OT to somewhere after OT, and I don't know the offsets and factors.

Okay, so some MIB data are simply hexadecimal values (0-FF) on a bit scale.
Does a value of 0 in MWB4 (start of funding) indicate a late start to funding, while a value of FF (255) indicates an early start, or is it the other way around?
Somewhere in between lies the optimum, which varies depending on the engine type, for example, 55 [units] at 1000 rpm and an engine temperature of 80°C or higher, is that correct?

PAPPL wrote:

Okay, so some MWB data are simply hexadecimal values (0-FF) on a bit scale.

That's how they all come from the MSG.
Based on "accompanying data," Lappi and MSG agree on which measurement value is currently being transmitted, and which offsets and factors should therefore be applied by Lappi for converting the data into a user-friendly format.

Quote:

0, in the context of the MWB4 (start of funding), indicates a late start to funding, while FF (255) indicates an early start to funding, or is it the other way around?

I don't know.

Quote:

Somewhere in between lies the optimum, which varies depending on the engine type, for example, 55 at 1000 rpm and an engine temperature of 80°C or higher, is that correct?

Yep.