VAG-Com: Optimize Engine Control Parameters

Hello,

I'm still working on my emergency power generator project.
Right now, I'm considering getting a TDI (specifically a 1Z).
There are several reasons for this, including the need to adjust to the operating point.
Hopefully, this will be much easier to do using VAG-COM.

I've read quite a bit already, but I still have some questions.

Can I adjust the injection timing using VAG-COM?

Can I use software to set the idle speed, for example, to 2000 RPM, and will the engine control unit (ECU) automatically adjust it based on changes in load?

Can I see the injection quantity while the system is running and simultaneously adjust the start of injection?

Sorry for asking such a silly question, but what I've found in my searches suggests that you can do some very nice things with VAG-Com. However, I have never worked with it before, and until now, I've always avoided using such modern technology.

The purpose of this exercise is to run the engine at approximately 2000 RPM in order to avoid certain problems that can occur when operating it at 1500 RPM.
- Oscillating vibrations.
- Incomplete combustion due to the requirement of relatively high power output at a low air-fuel ratio.
- Low efficiency due to low boost pressure.

Ultimately, this part needs to run on a Pöl system. That's why I also need to adjust the feed rate (FB).
If the fuel burn rate decreases, the fuel consumption also goes down; that's why I'm asking about considering both fuel burn rate (FB) and fuel consumption (FM) simultaneously.
The speed is initially somewhat arbitrary and can be adjusted relatively freely through the gearing to the generator.

Input needed.


Best regards, Hopel.

Hello hopel, why does it have to be a TDI? What is the maximum power output of the generator? I'm thinking about all the electronics and sensors, and even the immobilizer (except for the very old TDIs). You wouldn't need any of that with a mechanical diesel engine.

hopel wrote:

Ultimately, the part needs to be run on a lathe.

That's another argument in favor of using a mechanical swirl/pre-chamber diesel engine.

hopel wrote:

Can I adjust the injection timing using VAG-COM?

Within certain limits, yes, but it doesn't work with all tax devices. However, it is probably sufficient for use with wood-fired stoves.

hopel wrote:

Can I use software to set the idle speed, for example, to 2000 RPM, and will the engine control unit (ECU) automatically adjust it based on changes in load?

Not with VAGCOM. It might be possible by modifying the data set.

hopel wrote:

Can I see the injection quantity while the system is running and simultaneously adjust the start of injection?

No, not that I know of.

rubberduck wrote:

hopel wrote: Can I use software to set the idle speed, for example, to 2000 RPM, and will the engine control unit (ECU) automatically adjust it based on changes in load? Not with VAGCOM. It might be possible by modifying the data set.

Yes, it's possible. It can be done through the adaptation channels. But I don't know if it will reach 2000.

Yes, it can be changed through adaptation, but definitely not before the year 2000.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Hello,

The trend seems to be towards TDI engines because when I was researching them, I came across many DIY projects that were based on the same engine platform as the one I initially planned to use.
However, I came across some consumption patterns that were beyond the realm of good and bad.
It was all around 400g/kWh. This is likely also due to the lower efficiency.
What's still holding me back from buying the car is the question of which engine it actually has.
The component should ultimately produce around 15-20 kW of mechanical power. The Opel engines for which I have documentation would need to spin much faster, or they are very rare on the market, and I don't really want to install something exotic.
"A 1.6 or 1.9 engine would still be okay, but I don't want to deal with potential issues like warranty claims (KWS) and people trying to take advantage of the situation."
A 1.8-liter Ford? Not really necessary.

What's left then?

The TDI engine offers several advantages due to its electronic components.
The fuel consumption is highly dependent on the optimal fuel injection timing. With the older system, you have to adjust a setting and then run through "xx" liters of fuel until you can determine a fuel consumption value. With the TDI system, you simply adjust the fuel injection timing and read the amount of fuel injected (X) at a given power output (Y).
It's faster and much more informative.

Therefore, the question is whether both parameters can be viewed and modified simultaneously using VAG-Com.

The 1Z is also quite good for burning wood pellets. The main problem is the low combustion chamber temperature at low load, but that shouldn't be an issue for me with my 15kW system.
You can do a lot with the feedback controller (FB). I can even optimize it very precisely for a specific operating point.

The 2000 tours have been provisionally accepted for now.
It's important that the engine runs smoothly and has a full charge of lubricant.
I've read a lot about clutch problems occurring at around 1500 RPM. I also think that using too low a gear with relatively high load can increase fuel consumption.
It's similar to how his bowl is, like flooring it in 5th gear at 80 km/h while climbing the Irschenberg. Based on what I then see or don't see in the rearview mirror, something like that cannot be economically sensible.

If the transmission control unit (TCU) could take over speed regulation by simply modifying certain parameters to make the TCU believe that a specific RPM, say 2000, is the target idle speed, it would certainly save a lot of tinkering.

Regards,

Hopel.

hopel wrote:

If the transmission control unit (TCU) could take over speed regulation by simply modifying certain parameters to make the TCU believe that a specific RPM, say 2000, is the desired idle speed, it would certainly save a lot of tinkering.

Since you're already using all that electronic equipment, it might be possible to install a speed sensor that could provide the engine management system (MSG) with a speed signal. Then, the GRA (presumably a control unit) could regulate the engine speed based on that signal.

bastion wrote:

Yes, it's possible. It can be done through the adaptation channels. But I don't know if it will reach 2000.

Yes, I myself have adjusted it before due to vibrations in the low-frequency range. I believe it didn't even exceed 1000 RPM.

Hi,

I'm afraid that with such an engine, you won't achieve a great level of efficiency at the performance level you're aiming for. At 2000 RPM and full load, you're roughly at the point of highest efficiency, but your actual load is far from what the engine considers to be full load. You can easily calculate this: with 210 Nm of torque and 2000 RPM, you're producing almost 44 kW at full load. Your actual load is significantly lower than that, meaning you're not operating at full load and are therefore less efficient.

So, if you're aiming for efficiency, I would try to find the RPM that best matches your desired power output by looking at the torque curve, and where the engine is essentially running at full load.

A common side effect is definitely high wear and tear.

Best regards,

Jan.

"400 g/kWh is a too high value even for a combined heat and power (CHP) system. Is this measured including the generator efficiency? Otherwise, it only indicates an unfavorable operating point."

I'm only familiar with operating at 1500 or 3000 RPM. Do you want to "electronically generate" the 50 Hz?

Quote:

At 2000 revolutions per minute and full load, you are approximately at the point of highest efficiency, however, your load is far from what the engine considers to be full load. You can easily calculate this - with 210 Nm and 2000 revolutions per minute, you get almost 44 kW, which is what you have at full load. Your actual load is significantly lower than that, so you are not operating at full load and are therefore less efficient.

Of course, it becomes less efficient. Ultimately, what's crucial is how much load it needs to handle and how much fuel drips through the nozzles in the process. Due to vibrations, I wouldn't operate it at speeds below 2000 RPM, or not for very long.

Technically speaking, the engine is too powerful for the application and therefore inefficient, but it's extremely durable, more so than a more efficient engine that would constantly have to be operated at full load.

The engine speed could potentially also be controlled via the throttle position sensor or as an alternative function of it, if...
This function is programmed (or was previously programmed, like with older mechanical pumps) to act as a universal speed controller.

Hello,

I think that the 400g/kWh figure is only for electricity, and overall, that would be really bad.
However, it's also possible that many people aren't really expressing themselves clearly on this topic.

The approach using the GRA for the DZ regulation seems good; I'll think about it some more. What signal is received at the MSG? Is it a clock signal?

I don't want to go below 2000 RPM due to the vibrations; I prefer a higher speed. The 50 Hz is automatically determined by the generator's rotational speed. The gear ratio (GDZ) is adjusted accordingly.
The higher the gear I select, the further I move away from full load, and the efficiency decreases. Due to the translation/slippage, something probably won't work quite right.

It's clear that the 1Z engine is actually too powerful to run at full load, and this is also intended to improve its durability.

The engine came to mind because I was looking for something reliable and easily manageable. I think there will be plenty of "bargain" options available soon. The plan is to have one motor in operation and one in reserve, which would then be regularly overhauled.
The 1Z engine is relatively trouble-free when it comes to electrical parts and is also known for its durability. See 330,000 km "problem" .

Regards,

Hopel.

Have you ever considered a 1.4L TDI or the 1.7 SDI engine?
You get less power and better efficiency.

Hello,

The 1.7L SDI engine, like all SDIs, is not really suitable for use with racing fuel. Due to the lack of turbocharging, the temperature in the combustion chamber is lower. This has a very negative effect when using fuels with higher vaporization/ignition temperatures.

Regarding other TDIs, such as the 1.4-liter engine, I think that the acquisition costs alone are significantly higher than for the 1Z.
There are now quite a few used G3 models available on the market.
I don't think you can really make up for the difference through operating costs.

I once read somewhere that a diesel engine achieves its best efficiency at half load and two-thirds of its rated speed.
Maximum efficiency at full load makes sense, but the question is how to define it.
"When I give it full throttle going uphill, my engine is running at full load. Therefore, it should theoretically be operating at its most efficient point. However, since the car produces a lot of black smoke, especially in the lower RPM range, it's probably not very efficient."
Regarding the TDI engine, the soot limit should prevent such issues, but these problems are at least irrelevant in biodiesel operation...

Regards,

Hopel.

Hello hoppel,

Just use the 1Z engine and operate it at approximately 1500 RPM. To achieve your generator output of 15 kW, the engine will then be running at roughly 50% load (approximately 7 bar of mean pressure).
This load should, on the one hand, ensure sufficiently high combustion chamber temperatures and, on the other hand, promote good specific fuel consumption.
If you look at the consumption chart /viewtopic.php?t=2386,
Then the motor would have to be around 215 g/kWh. That's actually quite a decent value, isn't it?
I wouldn't worry about the durability either, because the engine is operating far from its maximum load and the speed is very low, which is gentle on the engine.
Even a rotational speed of 1250 RPM would still be considered non-critical in your specific application.

Regards,
Alex.

Typically, the optimal performance is achieved at slightly above 2000 RPM and just below full load.

Simple question: Why is the power consumption so important for "emergency power"? I personally wouldn't choose a PÖL (assuming this refers to a specific product or brand) even if it was only used occasionally.

Hello,

If it runs at all, this component won't just run occasionally; it will likely run almost non-stop.
Therefore, I am already paying close attention to the usage of the equipment.
The reason I want to increase the clutch engagement zone (DZ) is because I've read a lot about clutch problems that occur with low DZs. The clutch essentially gets shredded because the engine isn't running "smoothly" enough.

Regards,

Hopel.

"The interlocking mechanism will only engage when the load is at least half of its maximum capacity, as the high torque required for full engagement is not present."