Fundamental question: "Smoking regulations"

Hello everyone!

I have another idea, and I haven't found anything about it in the old posts, so I'd like to share it with everyone and hopefully 'please' them.

'I'm somehow bothered by the significant amount of smoke produced in various situations with my AFN (AGR closed, Box+ with 1.2 bar boost). This is especially noticeable in situations involving performance increases...'
I know that running a long injection time doesn't necessarily reduce soot, but I've already ordered larger injectors, and further increases in boost pressure and a larger turbocharger are also possibilities...

I still wonder if there isn't basically some way to perform a type of smoke measurement, with which one could simply reduce the injection amount until the smoking just disappears?
Perhaps with a (special?) oxygen sensor or something similar that measures the residual air in the exhaust...?

Perhaps someone has some ideas about this... I would appreciate any suggestions...

Greetings to everyone!

Michl.

Hello,

MichlM wrote:

I still wonder if there isn't basically some kind of smoke measurement method that could be used to simply reduce the injection amount until the smoking just stops? Perhaps with a (special?) oxygen sensor or something similar that measures the residual air in the exhaust...?

Conventional oxygen sensors for gasoline engines react to the oxygen in the exhaust. When oxygen is present, they adjust the fuel mixture to be richer; when it's absent, they adjust it to be leaner. This is essentially a two-point control system, like a coffee machine. However, they start to show readings even at a lambda value of 1.2-1.3, which means there must be at least a 20-30% oxygen excess in the exhaust. Therefore, the oxygen sensor is not functioning correctly. I once read somewhere that there are also "lean sensors" (which can still detect differences even in the lean range), and that might be something to consider. I adjust the fuel mixture in my older cars using my foot ; with low pressure and a cold engine, it smokes when I give it full throttle; when the engine is warm, it gets better. If necessary, one can also "smoke out" tailgaters or cyclists riding side-by-side.

Best regards, Uli.

Of course, you could use a lambda sensor to limit the fuel injection amount.

But: 1. The lambda value is not the same regardless of the engine speed.
2. The dynamics play a significant role in this.
3. The developer needs an incredibly long time to work on the application, so you'll have to wait.
cannot be done in 5 minutes.

The most common method for measuring turbidity is by measuring the cloudiness. This works in the...
The principle is similar to that of a light barrier.

But I have a better solution: Save up so you can buy a diesel that has the performance you want! I literally gag every time someone with their poorly modified TDI drives in front of me and I have to breathe in all that exhaust. Fortunately, OBD will soon be available for diesel engines, which hopefully will put an end to this nonsense!

Of course, you could use a lambda sensor to implement an injection quantity limitation.

But: 1. The lambda value is not the same regardless of the engine speed.
2. The dynamics play a significant role in this.
3. The developer needs an incredibly long time to work on the application, so you'll have to wait.
not able to do it in 5 minutes


Hello Ben1972!

'Regarding point 1: If that weren't the case, how would it work for gasoline engines, which are even precisely regulated based on that?'

Sure, here's the translation:

'Regarding point 2:'
I work as an electronics developer, and I've had to solve quite a few tricky problems (both professionally and privately, for example with cars), so I think I could handle this.

Regarding point 3: There was never any mention of 5 minutes.


The most common method for measuring turbidity is by measuring the cloudiness. This works in the...
The principle is the same as with a light barrier.

I've also considered that... but I imagine it would be very difficult to implement in the exhaust system, because any optics placed there would get very dirty very quickly.


But I have a better solution: Save up so you can buy a diesel car that has the performance you want! I actually vomit every time someone with their poorly modified TDI drives in front of me, and I have to breathe in the fumes...

Thank you for the hint...

1. I don't want any smoke either, otherwise I probably wouldn't have written this post.

2.: I know that there are stronger diesel fuels. But above all, there are WORSE ones!
I drive a Seat Cordoba Vario (estate/wagon) with a curb weight of 1100kg!
This vehicle is not available with a turbocharged (diesel) engine, not even as a VW Polo Variant. Besides, I can't afford, nor do I want, an 8- or 10-cylinder TDI or a 400CDI.

Because the rest of the diesel world (1.9PD, 2.5 TDI V6, 330d, etc.) doesn't impress me.
What's the point of having 180 horsepower if the car weighs 1600-1700 kg?

I drive 50 km of highway every day, and I haven't seen any of the diesel cars mentioned above that could pull away from me by even 5 meters when I'm driving at 170-180 km/h (..... by the way, in our country, Austria, the speed limit is only 130 km/h anyway. )

3.: This can help save fuel and taxes.

4.: Improving the performance of my cars is something I really enjoy.

Regards,
Michl.

Hi,

In diesel engines, the lambda value is never constant with engine speed because the power output is not controlled by a throttle valve (as in gasoline engines), but rather by the amount of fuel injected.

Simple methods for soot prevention:

- Feed the signal into the HFM (High-Frequency Modulation) system, and then the soot characteristic curve will be activated again.

or

- Turn the box slightly.

"In my opinion, your boost pressure setting seems quite high. It's difficult to get soot buildup with 1.2 bar of boost on that engine (unless something is broken)."

Best regards, Rainer.

Hi,

Lambda in diesel engines is never directly proportional to the engine speed, because the power is not controlled by a throttle valve (as in gasoline engines), but by the amount of fuel injected.

Hello Rainer!

No, no, I understand that a diesel engine operates with an excess of air, which naturally varies depending on the amount of fuel injected... I just meant that the lambda value remains constant at the same ratio of residual oxygen to exhaust gas volume, regardless of engine speed... Maybe I didn't quite understand what Ben1972 was referring to...



....IMHO, your setup is quite extreme. It's difficult to get soot with 1.2 bar of boost on that engine (unless something is broken).

Well, to be precise, it's more like 1.1 to 1.15 bar using a steam turbine.
So, the mass airflow sensor is currently not reporting too much airflow, and that's why the emergency mode is being activated.

Furthermore, it doesn't always work, sometimes more, sometimes less... it seems to depend on the position of the stars and the lunar phase ... but mostly it starts working above 3500 RPM.

.. I hope nothing is broken !!

Best regards,
Michl.

Hello Michl,

What you need is a wideband lambda sensor. Unlike a standard (two-point) sensor, this provides a signal that varies depending on the lambda value (characteristic curve). The new gasoline direct injection engines have and require such sensors.

If you were to implement your regulation, you certainly wouldn't enjoy driving anymore. Current diesel engines already operate in areas just below lambda 1 during significant dynamic load and speed changes, which naturally results in a corresponding amount of soot emissions. Nothing comes from nothing.

Best regards,
Albrecht.

Hello Michl,

Would you like to try something like that sometime? I have something like that. (Manufacturer: NGK, new).

Information on the NGK / NTK homepage.

Standard probes emit a nearly digital signal, and the Lambda 1 range is very narrow. This generates a voltage signal that is 'analog' to the oxygen content.

How long can it withstand the soot? No idea!


Regards,

http://www.ngkntk.de/de/

Hello Michl,

Would you like to try something like that sometime? I have something like that. (Manufacturer: NGK, new).

Information on the NGK / NTK homepage.

Standard probes emit an almost digital signal, and the Lambda 1 range is very narrow. This generates a voltage signal 'analog' to the oxygen content.

Hello Garth!

Yes, something like that would be exactly right...
Unfortunately, I haven't found anything about it on the internet on all the possible NGK websites...

The FSI has a total of 3 probes, right? Which one is the correct one?

Can you perhaps give me the model number or a link?


How long can it withstand the soot? No idea!


That's a good question...

1. If I want to reduce the amount of soot produced by this measure, then not nearly as much soot should end up on the probe.

2.: Lambda sensors typically don't actually break, they just become SLOWER.

Since I don't need to strictly adhere to the regulations for gasoline engines, as I'm not concerned about the sudden burst of power when accelerating, but rather about reducing the continuous soot emissions at full throttle (1-2 seconds). The time constant) might mean that the whole thing could still work with a somewhat unreliable, slow, but still fast enough probe for my purposes.

Best regards,

Michl.

Does anyone have data on what the oxygen content is in the exhaust gas when a TDI engine starts to produce noticeable black smoke? It's probably still around 1-2%, but what is the actual value?

It depends on whether it's even possible to use lambda probes.

'Due to the enormous pressure on the manufacturers, I believe they would have already developed a way to measure the turbidity if there were a stable solution for continuous use.'

Does anyone have data on what the oxygen content in the exhaust is when a TDI engine starts to noticeably produce black smoke? It's certainly still around 1-2%, but what is the actual amount?

It depends on whether it's even possible to use lambda probes.

Due to the enormous pressure on the manufacturers, I believe they would have already developed something to measure the turbidity if there were a stable solution for continuous use.

Hello Garth!

Of course, it works ... just look here:

LINK TO REPORT

(I'm just ahead of my time again... )

You need a measuring lambda sensor for this... I read that they measure from a lambda value of 0.8 to 2.5... that should be a sufficient measurement range.
And from which lambda value the injection amount actually needs to be reduced can be determined quite quickly in driving tests (while looking in the rearview mirror )!

Best regards and thank you for your message!

Michl.

Hello!

You can also adjust the fuel injection amount directly at the fuel injection pump!
With that, you can get any TDI to quit smoking .
To do this, you need to slide the cover of the fuel injection pump, and it will become thicker in the direction of the hose connections. However, you'll need a special socket, as one screw has a rounded-off hexagonal head, while the other three are Torx screws.
You can only move fractions of a millimeter, and you can control this via the OBD interface in engine control unit 01, measurement block 1, field 1. Value (mg/h) = the lower the value, the richer the mixture.
Ideally, every Bosch service center should be able to do that.
Since most people prefer a very lean setup, this is also a tuning approach.
'It made a significant difference for my friend's 110 Syncro; it was extremely slow before.'
It was even extremely too lean, just slightly off from being too rich, and sure enough, where you used to need 3rd gear, now 4th gear is enough for acceleration.

Hi,

passidriver wrote:

Hello! You can also adjust the fuel injection amount directly at the fuel injection pump! With that, you can get any TDI to quit smoking . To do this, you need to slide the cover of the fuel injection pump, and it will become thicker in the direction of the hose connections. However, you'll need a special socket, as one screw has a rounded-off hexagonal head, while the other three are Torx screws. You can only move fractions of a millimeter, and you can control this via the OBD interface in engine control unit 01, measurement block 1, field 1. Value (mg/h) = the lower the value, the richer the mixture. Ideally, every Bosch service center should be able to do that. Since most people prefer a very lean setup, this is also a tuning approach. "It made a significant difference for my friend's 110 Syncro; it was extremely slow before." It was even extremely too lean, just slightly off from being too rich, and lo and behold, where you used to need 3rd gear, now 4th gear is enough for acceleration.

Great that you found the search function.

However, a regular Bosch service center will likely not be able to help you with your request.

However, I don't see any point in compensating for the increased fuel injection volume of the turbocharger by manipulating the fuel injection pump.

In my opinion, the action is pointless, and the performance that could be extracted with a probe, varying depending on weather conditions and the time of day, is not worth the entire effort.

Just turn your volume down a little bit, and you're all set!

Best regards, Rainer.

Hello,

No, I'm sorry, I couldn't find it in the search function.
I've had to adjust things like that before, for example, with vehicles that had a complete tuning control unit installed, where you couldn't adjust anything and it was making too much noise.
And, as I mentioned before, this also applies to privately owned Passats, where measurable improvements can be observed.
It's possible that the Bosch service doesn't do it, but they at least have the socket.
You need to know how and what to adjust, and without an OBD scanner, nothing can be done.
Repair manuals often include specified values with tolerances. If a value falls outside of these tolerances, the manual might state something like: 'replace the fuel injection pump,'
However, this value can be adjusted.
For example, in my girlfriend's Passat, we had target values of 3mg/h to 6mg/h, but his was at 8!!
Set to 2.9, it runs significantly faster.
I specifically checked customer vehicles, and a large proportion were within the upper tolerance range.

However, I don't see any point in compensating for the increased fuel injection volume of the turbocharger by manipulating the fuel injection pump.

In my opinion, the action is pointless, and the performance that could be extracted with a probe, varying depending on weather conditions and the time of day, is not worth the entire effort.

Just turn your volume down a little bit, and you're all set!

Greetings, Rainer

Hello Rainer!

Sorry, but I have to say something about this:

'I understand that this isn't necessarily a dedicated 'tuning' forum.'

2.: I also understand that this is your forum, and that you can simply disable posts that you feel don't 'fit' or are inappropriate, and that you do so.


What I don't quite understand is why you seem so resistant to a lively discussion about the technical possibilities for addressing a significant problem with diesel engines (soot).

Don't you think I know that I can turn the knob further back?

It's just that when I adjust them in a way that I never see even the slightest puff of smoke in the rearview mirror, regardless of the operating conditions, I subjectively might only get about half the performance increase I'm getting now!
(I could also remove the box, then it wouldn't smoke at all! )


As an experienced tinkerer, I sometimes think a bit further... maybe I sometimes go too far... but that doesn't mean you have to treat me like the author of a 'HOW-DO-I-CHANGE-THE-AIR-FILTER' post, does it?

Regards,

Michl.

MichlM wrote:

It's just that when I adjust them in a way that I never see even a single puff of smoke in the rearview mirror, regardless of the operating conditions, then I might only experience about half the performance increase I have now! (I could also remove the box, then it wouldn't smoke at all! )

Hi Michl,
I find it somewhat pointless to try and optimize every minute detail of a fundamentally "brute force" type of speaker setup (which speakers are, by their nature, regardless of whether I own one myself).

The effort required for this will ultimately "outweigh" the already available alternative (namely, a good chip tuning) by a significant margin... so what's the point of all the complications ?