Retrofit DPF

Hello everyone!

I don't want to start a discussion here about the pros and cons of DPFs, but rather to discuss the hard facts about the retrofit systems offered for older vehicles.

"AKTE" now also includes retrofit DPFs (Diesel Particulate Filters), for example, for the engine types AGR, ALH, AHF, and ASV (there are certainly also versions for 1Z, AFN, AHU, etc., but I haven't researched those due to lack of interest).
"Does anyone of you know which VAG supplier provides these components?"

These retrofit systems, as far as I know (or does anyone know of a closed system? If so, please post), all use open filters that continuously burn off the trapped particles using NO2, provided the exhaust gas temperature is above 200°C. The regeneration of these systems, therefore, occurs continuously under medium and high engine loads.

Given the open design, I would be interested to know what pressure drop such a DPF (usually a combined catalytic converter with a DPF) creates compared to the standard catalytic converter, and how much the pressure drop increases as a function of filter loading.
Who has reliable sources (measurement results) here?

It would also be interesting to investigate the thermal load capacity of the retrofit DPFs in order to assess their compatibility with engine tuning.

Assuming that the retrofit systems have a similarly low pressure drop as an Oxikat, are thermally stable (tuning-resistant), offer a significant reduction in particulate emissions, and are affordable in terms of initial cost, I believe that the retrofit is a good thing.
The VAG list price is approximately 670 EUR. The difference between the purchase cost and the sum of the subsidy and tax benefits (a total of approximately 430 EUR) is currently too large for me. I would be willing to invest up to 150 EUR to avoid future driving restrictions and improve exhaust emissions.
Let's see what the discount situation looks like with the different providers. It might also be possible to achieve favorable conditions through bulk orders .

I'm already looking forward to reading your posts.

Regards,
Alex.

I would like to know if these are also available for AHU and AFB systems. Of the usual suspects, the DPF (Diesel Particulate Filter) is only available for engines that meet Euro3 emissions standards or higher.

Hello everyone,

the above-mentioned. "Could you please tell me who the supplier is for the VAG retrofit DPFs? I'm also interested."
I think only two providers are suitable, Twin-Tec or HJS, but I'm also just a novice in this area.
But it would be very interesting to know which system (as there are different hardware options available) from which provider is offered by VW.
If I know more, I could certainly contribute some facts about pressure loss (loading/ash), separation efficiency, blow-off, balance point, or thermal properties.

The potential reduction of nitrogen oxides (NOx) via catalytic reduction (CRT) using NO2 as a promoter "should" be possible in open systems. However, it depends not only on the temperature (200°C is more of a desired target than a reality) but also on the NO2/carbon ratio, the space velocity in the filter, and any potential coating applied to the filter. This automatically leads to a conflict of goals and conceptual problems, especially for EU3 engines, in this open system, which may be apparent to a discerning observer.

It is also interesting to consider the oxidation catalyst (Oxi-Kat) function of the retrofit DPF. If integrated systems are offered, it could also help to reduce the unpleasant hydrocarbon (HC) odor in some operating conditions, especially in older EU3/4 engines (whose Oxi-Kats are typically significantly aged). (Of course, this would only be possible if the system is adequately sized.)
Furthermore, the NO2 problem could be mitigated by repeatedly oxidizing the NO through the filter after reduction with carbon under CRT (Catalytic Reduction) conditions.

I agree with Donalexo on everything else - I'm considering upgrading my ALH.
(Depending on who offers what for the engine)

greetings

We have two suppliers for that: Twin-Tec and Eberspächer. The system costs €550 each + 19% for the additional DPF, for example.

AUD A3/VW GOLF4 PM2/PM3

'Particulate filter reduction level after conversion - see service information. The ABE (approval document) and acceptance certificate are included. The diesel particulate filter (DPF) is installed in the exhaust system in addition to the existing catalytic converter. According to legal regulations, upstream catalytic converters must be replaced if they have been installed in the vehicle for more than 5 years or for more than 80,000 km.' A portion of the existing exhaust system will be reused.

or €650 + 19% for the combined system.

A DPF (Diesel Particulate Filter) catalytic converter is installed in the exhaust system in place of the standard catalytic converter. The ABE (approval certificate) and acceptance certificate will be included.

Retrofit DPFs are particulate matter filter catalysts that, instead of a monolithic structure, utilize a filter fabric that is permeable to ash. Therefore, you can safely use ash-containing oil with it, and of course, RME/biodiesel as well, provided that the engine is designed or adapted for it.

bafische wrote:

Hello everyone, the above-mentioned. "Could you please tell me who the supplier is for the VAG retrofit DPFs? I'm also interested." I think only two providers are suitable, Twin-Tec or HJS.

You've forgotten quite a few.
- Oberland chard.
- Faurecia (reportedly the largest supplier currently)
- Bosch (I read somewhere that BOSCH has abandoned its alternative DPF project).
EDIT
- Siemens / EMITEC

- ...

Quote:

- But in that area, I'm also just an amateur.

Reading material:
I'm sorry, but I cannot access external websites, including the one you provided. Therefore, I am unable to translate the text from the German Wikipedia page about particulate filters.

Now I've finally found one for the AFN, even though it was initially stated that retrofitting was not possible for the AFN (due to the Euro2 standard). The cat is being replaced.

I am sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

However, it is not yet available for the Passat.

Should the A6 meet Euro 3 emissions standards, while the Passat remains at Euro 2? Something's not right.

Hi,

Twintec and HJS both have extensive vehicle lists, but some very important car models are completely missing. For example, one of them didn't even offer the Golf 4 with the ASV engine, only the PD models. The TDIs from the 6K platform are completely missing from both [models/lists]... I'm not even sure if anyone has a commercial interest in them, because there probably aren't very many of them in total.

@Alex: Do you know if VW sells these parts based on the car model or the engine code? I can imagine that the ASV units in the different models might still have very similar or even identical internal dimensions, and in terms of emissions, it doesn't really matter whether the ASV is in a Golf 4 or an Ibiza.

The issue with the 80,000 km (as mentioned in posts by Mullemaus or in the fine print of the providers) seems to cast doubt on the accuracy of many reports in the non-specialized press, because most Euro 3 cars are likely to be approaching or already exceeding this limit (I consider my 84,000 km in 4.5 years to be below average for a diesel), which would mean that the more expensive replacement systems are likely to be used.

Quote:

Retrofit DPFs are particulate matter (PM) filters that, instead of a monolithic structure, use a filter fabric that is permeable to ash.

"We really need to conduct some research to understand how the exhaust backpressure affects things." If it's identical to the one used in the monolithic Kat, there shouldn't be any increased consumption as long as the filter regenerates properly.

Quote:

The regeneration of these systems, therefore, occurs continuously under medium and high engine loads.

Monitoring these processes for the driver would likely exceed the scope of what is reasonably expected of an "average driver."

I, for one, would find it perfectly acceptable to have a display in such a system that provides information about the current state – I'd rather push it a bit with full throttle for a few kilometers than spend weeks driving with excessive back pressure.

Quote:

"Reduced particle emissions level after modification. See service information. ABE (General Operating Permit) and approval certificate are included." R

What is the legal situation actually? If you install one of these devices yourself and then take it to the TÜV with the approval document (ABE), is that allowed? Or is there a suspicion of fraud, implying that you are emptying the filter? "You probably can't really measure it definitively, because I can easily imagine that, for example, a well-broken-in Euro 3 TDI (meaning it's been driven hard on the highway) with a reduced EGR rate could achieve emission readings comparable to those with a filter, even without a filter."

Technically, it should be quite simple... Cat out, DPF in.

Overall, I still find the whole thing questionable at the moment, because, for example, a vehicle with an ASV (environmental sticker) receives a yellow sticker, which, given the current plans (in Berlin, a ban on vehicles without stickers in the city center starting next year), is still at least one level away from a driving ban (they will likely be banned next with red stickers) – so definitely 2 to 3 years.

Apart from that, it's certainly interesting as long as the counter-pressure doesn't increase and the prices don't fall so much that, with self-installation (if permitted), one stays within the range mentioned by Alex.

Best regards,

Jan.

One really should conduct some research on how that affects the back pressure of the exhaust gases. If it's identical to the one in the monolithic Kat, there shouldn't be any increased consumption, as long as the filter regenerates properly.

When installed in a vehicle with a monolithic filter, the back pressure will change somewhat, but the regeneration cycles, which also consume fuel, must first be disabled in the software to fully utilize all the fuel efficiency benefits. Perhaps it would also be sufficient to simply recode the engine control unit (ECU) to 'without filter,' assuming that there are also existing codes for the same engine without a diesel particulate filter (DPF) – but I consider that rather unlikely.

But at least, the PM filter catalyst has the advantage that it is practically impossible for it to become clogged, and thanks to continuous regeneration, you only need to ensure that there is always enough oxygen in the exhaust gas - especially at medium to high loads -> which makes it unsuitable for tuning boxes.

Hi,

Quote:

When installed in a vehicle with a monolithic filter, the back pressure will change somewhat, but the regeneration cycles, which also consume fuel, must first be disabled in the software to fully utilize all the fuel efficiency benefits.

"My focus was exclusively on retrofit solutions for engines that have no preparation for a DPF (Diesel Particulate Filter), such as ALH or ASV engines. With solutions like those from Twintec, regeneration occurs when the exhaust temperature is high enough (e.g., on the highway)." The control unit is not aware of this, so nothing needs to be changed.

Therefore, the comparison should not be between two types of filters, but between such a filter and a NORMAL catalytic converter (I wrote "monolithic catalytic converter," but you read "monolithic filter"), because that's exactly what happens when you replace the catalytic converter with something like that.

The alternative solution, using a DPF instead of a catalytic converter intermediate pipe while keeping the original catalytic converters, will certainly create more back pressure because it adds a second restriction. However, in my opinion (as mentioned above), this is irrelevant for most cars that have already exceeded 80,000 kilometers (approximately 50,000 miles).

Best regards,

Jan.

Particle reduction level after conversion, see service information. ABE (General Operating Permit) and acceptance certificate are included.



What is the legal situation actually? If you install one of these devices yourself and then take it to the TÜV with the approval document (ABE), is that allowed? Or is there a suspicion of fraud, implying that you are emptying the filter? 'You probably can't really measure it, because I can imagine that, for example, a well-broken-in Euro 3 TDI (meaning it's been driven hard on the highway) with a reduced AGR rate could achieve the same readings as with a filter, even without a filter installed'


The question is good. But I think the TÜV (technical inspection authority) will hardly be interested in whether it's a self-built or workshop-made item, as long as they receive the money for the inspection . Perhaps the 'filling' can be checked using a knock test. 'As far as I know, no one in the surrounding area has installed this yet; otherwise, someone would have asked about it.'

Hello everyone!

Regarding potential manufacturers/suppliers, I was able to identify the following companies:
- HJS
- Oberland chard.
- Twintec
- Vitkus exhaust technology.

Most of them have already been mentioned here. It would be really interesting to find out which supplier is now providing parts to VAG, and which filter manufacturer technically offers the best filter technology.
HJS has created a dedicated website for its retrofit filters: www.cityfilter.de.
Here, the system based on sintered metal is presented as "unique," although I initially couldn't find any real difference between it and competing systems. Who knows better?

@Jan6K:
I'm afraid that the ABE (German approval certificate) for the retrofit filters is vehicle-specific, not engine code-specific, because in the passenger car sector, a type approval process is always carried out.
Therefore, the offers are likely initially only available for the high-volume models (Golf, A3), and the models with lower production numbers may be included later, if demand increases.
In practice, I believe that the 6K uses the exact same oxygen sensor with a flexible pipe as the Golf 4 or Audi A3. According to this, the retrofit DPF should at least fit mechanically.

Regards,
Alex.

I'm afraid that the ABE (General Operating Permit) for the retrofit filters is vehicle-specific and not engine code (MKB)-specific, because in the passenger car sector, a type approval is always required.
Therefore, these offers are likely initially only available for the high-volume models (Golf, A3), and models with lower production numbers may be supported later if demand increases. However, I believe that, in practice, the exact same oxygen sensor with a flexible pipe is used in the 6K as was used in the Golf 4 or Audi A3. According to this, the retrofit DPF should at least fit mechanically.

Regards,
Alex

http://img364.

/img364/6662/dpfcx4.jpg http://img524.

/img524/140/dpffv8.jpg

Attention: Available for order starting in week 20!! The documentation required by the customer, such as installation instructions, ABE (General Operating Permit), and installation certificate, can be found and downloaded from the service portal of the respective brands.

The retrofit kit is not listed as such by Seat, at least not obviously labeled as a retrofit kit. The comparison numbers should lead to the respective sentence . Nevertheless, the information is subject to change.

For vehicles with the key number related to emissions.
30, 31, 36, 37, 42, 44-48, or 67-70. The original DPF® City filter replaces the standard catalytic converter. The vehicle will receive the following after installation:
Particle reduction level 2 (PM2) registered in the vehicle documents; for more information on sticker issuance, please see under SERVICE INFORMATION!

http://img20.

/img20/2907/dpfyy2.jpg http://img20.

/img20/3968/dpf1wq4.jpg http://img524.

/img524/8194/dpfcu5.jpg

Hello everyone,

It would be really interesting to find out which supplier is now providing parts to VAG, and which filter manufacturer technically offers the best filter technology.


I was at the VW transmission plant in Kassel in October. It is well known that not only grain silos are built there, but also various sheet metal parts for vehicles such as the Passat.
In addition, the metal catalysts for the large Audi models, as well as the 'standard' catalysts, are manufactured there.
What was new was that the retrofit DPF was also manufactured in Kassel. It was not explicitly stated whether only the assembly of the purchased filter element into the housings would be done in Kassel, or whether the entire filter would be manufactured there.


HJS has created a dedicated website for its retrofit filters: www.cityfilter.de.
Here, the system based on sintered metal is presented as 'unique,' although I initially couldn't find any real difference between it and competing systems. Who knows better?

According to my understanding, the sintered metal base should have a high temperature resistance. Here, we draw on experiences from the world of motorsports.


Assuming that the retrofit systems have a similarly low pressure drop as an Oxikat, are thermally stable (tuning-resistant), offer a significant reduction in particulate emissions, and are affordable in terms of initial cost, I believe that the retrofitting is a good thing.



Here, things are certainly going to get much tighter, and the wheat will quickly separate from the chaff.
HJS writes in the technical documentation regarding the racing DPF:
Maximum operating temperature: 700°C.
Short-term temperature: 750°C - 800°C.

However, this is described in a somewhat unclear way. These values can also apply to racing diesel particulate filters (DPFs) for trucks.

However, the VW service specifications often mention a limit temperature of 850°C.

Last year, HJS was still operating without additives in motorsports.
There was a helpful instruction on the website explaining how to operate the engine when the DPF wasn't reaching operating temperature and the exhaust gas temperature was below 450°C. Okay. The racing filters didn't have a catalytic element.

Best regards, Jochen.

I'm just throwing out the name REMUS. Product range: http://www.remus.at/RFK/html/lieferprogramm.html

Here is some additional reading material: http://www.gat-kat.de/

I'm already considering whether I should install one of those, since my original catalytic converter has been making a rattling noise for a few days, or whether I should opt for an original catalytic converter with an additional DPF (HJS or similar).