Diode Tuning: Understanding Engine Characteristics.

Hello everyone.

Diesel.Gustav's postings under https://community.dieselschrauber.org/en/viewtopic.php?t=2492
Could you please explain the somewhat "strange" reaction of the TDIs to the 10c diode tuning?

Based on forum experiences, the effect of this modification is mainly noticeable in the higher RPM range, while a "normal" 10c tuning only has a uniform effect across the entire range through the use of a resistor.

My theory about it is:
When, starting at approximately 3000 rpm, the injection rate (mass per time) is primarily determined by the nozzle diameter, even with increasing pump pressure, the injection duration must be increased to maintain the full-load injection volume as the engine speed rises. This means that the quantity control mechanism must be adjusted beyond the full-load position for lower engine speeds.
As the RWG voltage increases, it increasingly limits the performance of the 10c diode tuning, resulting in a particularly noticeable effect in the higher speed range.

According to this, aggressive diode tuning could be particularly dangerous for piston seizure.
If the already extended high-RPM fuel injection is further prolonged through tuning, it's my opinion that you can relatively quickly approach the point where the pistons start to melt, even though the "ultimate power" may not even be achieved in the mid-RPM range.

What do the pump experts say about it?

Could this increased risk also be a reason why, to my knowledge, no tuning plugs or boxes with RWG signal distortion achieved through diodes are offered?

'So, my 'box' switches 300 ohms in parallel. This is the limit where no emergency shutdown occurs, and the smoke production is in the range of old, slow-speed diesel engines.'

The surge starts from idle speed and increases rapidly up to about 3500 RPM, then it fades away. At the rated speed, you can barely feel anything, and there's no noticeable smoke.

In terms of pure performance, it could potentially achieve even more, but then it would run poorly and go into limp mode at higher RPMs (due to the bypass valve hitting its maximum limit, etc.).

It seems that the fact that it doesn't produce more power at high RPM is an indication that, at least for the ALH automatic (with a different pump and injectors!), the maximum fuel delivery is well-tuned .

If someone's acting like a puppet, we could hook up the oscilloscope and see what's going on. I'm feeling incredibly lazy right now...

'By the way: I would design the box so that it automatically adjusts the setpoint back to the actual value and actively controls the switchgear itself. This would be great for the EDC (Electronic Data Carrier), and I could create my own characteristic curve. It's not a problem with a few operations. Or I could use a PIC microcontroller or something similar...'

CU Gremlin.

Gremlin wrote:

It seems that the fact that it doesn't produce more power at high RPM is an indication that, at least for the ALH automatic (with a different pump and injectors!), the maximum fuel delivery is well-tuned

.
Hi Gremlin.

...or that the nozzles themselves are practically the primary cause of the shut-off: the pump's stroke seems to become so short in time that virtually nothing comes out of the narrow nozzles during that period - even if you extend the pump's operating phase by 20 or 30%, it doesn't seem to fundamentally change this.

I'll measure the voltage at the throttle control sometime (when I'm less lazy). I suspect it's simply set to full throttle, and that's the limit.

'Is there a channel where someone is discussing the voltage that the EDC (Electronic Data Carrier) applies to the slider?' *searching*

CU Gremlin.

Gremlin wrote:

I'll measure the voltage at the throttle

at some point (when the laziness subsides). I suspect it's simply set to full throttle, and that's the limit...

Hi Gremlin.

. . . . but then shouldn't the error "Rule violation . . ." reappear

Quote:

was not in any channel, and does the voltage that the EDC applies also affect the slider? *rummaging*

If you mean the voltage for the MSW (instead of from } the RWG) - I don't think so; the EDC, as far as I know, only reports RWG voltages, including the stored values for the upper and lower limits from the last pump start check.

. . . . but then shouldn't the error 'Rule violation . . .' reappear




He does, yes, when I go below 300 ohms .

I see what you mean... a pack of 50 capsules for cappuccino, a slave shop, and then maybe 81...


CU Gremlin.

Gremlin wrote:

I see... a pack of 50 cappuccinos, a slave shop, and maybe even up to 81...

Hi Gremlin.

Yes, go ahead - that should provide material for another specialist article .