diesel particulate filters (DPF)

They're required on a lot of diesel's in Europe, none in the US. Pluses, minuses, where to get them? Discuss:

I wonder who can import them?

BEEEEEE CAREFULLLLLL ...

I am getting the impression that someone wants to retrofit one of these to their car that was not originally so equipped.

To correct one small detail, DPF will be present on 2008 VW diesels in North America, and they are already present on all the pickup truck diesels for 2007.

Anyhow ... If you bolt one of these onto the exhaust system, it will simply clog in no time. DPF's require changes to the engine control strategy in order to implement the regeneration cycle for the DPF. Initiating the regeneration cycle requires operating at very high exhaust gas temperature, which your existing turbo might not be able to handle. It is NOT that simple.

All of this has been discussed before; search the forums.

DPF's either use an active regeneration (ie, engine management and other ways to increase egt, or systems found in bluetec) or a "passive" catalyst added to the DPF.

Since VW's retrofit is a bolt-on process-- I will have to assume it is a passive catalyst that is added to the DPF.

/me goes off to search. Yea, I was looking to retrofit. Also looking to see what it would do to my power and exaust flow. (what it's head loss is)

The DPF has been getting a lot of bad press over here in europe. They keep on blocking up or not regenerating as they should. It was a bad design rushed in by the VAG group so as to get their cars though EU emission laws. Here is some offical reading for you. DPF

To the original poster, you've probably gathered by now that there is a retrofit kit available in Germany which was essentially imposed on the manufacturers by the government. (That's a huge flashing warning sign right there.)

20Indigo, is there any re-flashing of the ECU involved as part of this "bolt-on" process?

I'm not surprised at hearing that the DPF's retrofitted to the older cars are causing trouble. The distributor-pump and P-D engines have no way of artificially increasing EGT to induce a regeneration cycle beyond simply retarding the injection timing within the bounds of what the mechanical parts will allow. If someone putters around town slowly and never puts the engine under heavy enough load to induce regeneration, then it's only a matter of time before the DPF clogs. And there is no way for the electronics to monitor the DPF. (The newer systems monitor pressure drop across the filter so that they can tell when a forced regeneration is necessary, but this requires sensors and additional I/O for the ECU which are not there on the older cars.) If there is any provision for active regeneration at all, it can only be based on the software taking a "guess" when the DPF needs it. I just can't see that process working all that well.

reminder to self: don't buy a car with a DPF until a few years down the road, after the technology proves itself and the initial bugs are solved.

side note, I read the document devonmikey posted. Looks like these retrofits use totally passive regeneration. A warning lamp comes on (which your existing instrument cluster doesn't have!) and then you have to drive a certain way to raise the exhaust temperature. Says right in that document that inner-city driving conditions or the Channel Islands (too small to have any highways or any long trips) aren't suitable.

Personally, my own driving patterns would regenerate the DPF every time I drive the car, but that's another matter ...

I think you're getting some things confused.

the pdf devonmikeyboy posted deals with factory installed DPF with active regeneration.

The retrofit, AFAIK, does not contain a new ECU program, hence a passive generative dpf. The retrofit "install kit" only consists of the gasket, nuts & new mount/bolt.

Back to the US shores, many of the heavy duty diesel dpf retrofit utilize a passive regenerative dpf only.

yeah, I was a little confused, but I think I'm unconfused now. The OEM DPF is as described in that PDF. The retrofit DPF sounds like the same thing but without the warning lamp and without *any* means of helping the regeneration along.

The PDF suggests a lack of active regeneration. (It might be retarding the injection timing to coax it along, but we don't know that. The retrofit kit would not have such capability.) It does, however, have a monitoring system and warning lamp to TELL the driver when he has to change his driving patterns in order to MAKE the passive regeneration happen. A truly active regeneration system doesn't require any change to driving patterns; it raises the exhaust temperature by other means (fuel injection during exhaust stroke, etc.) which distributor-pumps and P-D's have no mechanical capability of doing. A retrofit DPF on a light duty vehicle won't even have the warning lamp ... the DPF will simply clog up if the driver doesn't drive the car hard enough and frequently enough.

Heavy duty trucks generally run under heavy load frequently enough so that passive regeneration is OK. That's not necessarily the case with a light-duty application.

The lack of any monitoring or reprogramming means you COULD, theoretically, install this DPF on a North American vehicle. 'Course, you'll have to pay the full cost of the part, since the subsidy available in Europe (forced by the government) isn't available. And whatever troubles the Europeans are having with this, you'll have as well. No thanks!

got a price from impex..... $1100.

Not too suprising, but still... ouch. Wish I had disposable income

Sounds like roughly the going rate for a catalytic converter, which is basically what this is.

A particulate filter is not an oxidizer catalyst. It is what the name implies a filter. The innards of a DPF, diesel particulate filter is made of a porous ceramic material sometimes bonded with platinum for a catalyst, There is no unrestricted path through which is why they clog at will. A DOC, diesel oxidizing catalyst is just a platinum matrix, looks like a great big honeycomb inside, and exhaust can flow through relatively freely

I REALIZE THAT. But the point is that it is a piece of pipe filled with a substrate coated with catalytic materials. The substrate is different and the catalytic materials are different but the amount of "stuff" involved in a DPF is comparable to the amount of "stuff" involved in a normal oxidation catalyst, it's just that the details of the "stuff" are different. Hence the price is not much different.

Sorry just try to explain to everyone why a DPF Plugs and a DOC typically wont plug.

Ah - couldn't tell where the emphasis was. Yep, you got that right.

I post pictures how DPF looks in new 2.0 tdi engine BRM (170hp). So I don`t think there is easy way to fit this to old tdi engins.

ebay has the best prices:
http://search.ebay.de/partikelfilter

an additive for DPF's:
http://cgi.ebay.de/Diesel-Additiv-3...ryZ30170QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

Its something I would not retrofit to an old machine. My way of thinking is that it would induce problems. Something of this nature I feel has to be engineered as a complete package in order for it to be reliable and safe.

"I post pictures how DPF looks in new 2.0 tdi engine BRM (170hp). So I don`t think there is easy way to fit this to old tdi engins."

"Something of this nature I feel has to be engineered as a complete package"

AFAIK, this is happening in Germany. Several cities have mandataed DPF's for older diesels. If you want to drive in the city, you have to have a DPF.
There are a couple German aftermarket DPF kit makers who have computer controlled systems.

Thnaks for the pic. I had no idea the DPF was so close to the engine.

Here is the whole system for the 2008 model year. Having been up close and personal with this system this is in fact the one we will be seeing in every detail.

My MB is nearly identical, the catalyst (2 feet of it) is mounted directly to the turbo outlet and makes up the majority of the downpipe...

DB

OK, here's an idea-- how about a modular DPF you pull out of your car every week/month, dump it out, and stick in on the BBQ pit for a quick roast, and plug it back in.

Of course it would be a toaster oven or purpose built unit etc you get the drift--the heat doesn't have to come from the engine.

Build a bypass valve (with a whistle) into the unit if it plugs before you have the neighbors over for a cookout.

Nothing technologically advanced here..

OK, now that we've cleared that up....

In case you're interested, a bunch of companies make aftermarket DPFs to be retrofitted onto diesel construction equipment, tractors, etc. Usually they are not regenerated, they just come off and you vacuum or blow them clean (thereby, of course, defeating the whole purpose of having a DPF, but what the hey).

Totally impractical, of course...a great solution for a tractor that covers maybe 5 miles a day, but you'd have to be nuts to hook one up to a car and look forward to cleaning your DPF every evening after you get home from work.

So far, the DPF on the '09 Jetta looks like a nice piece of work; very little fuel economy hit, no performance hit (so far), and if you didn't know it was there you wouldn't know it was there (wait a minute....). So far. Ask me again about 2 years from now, though.

I wouldn't mind something that I could clean once a month, or even once a week--daily, no. Otherwise I'll have to wait for my next car

mijbo11 said:

Sorry just try to explain to everyone why a DPF Plugs and a DOC typically wont plug.

Click to expand...

Velocity of the exhaust is the difference. Putter around town with feather accelerator pedal pressure and you will plug a cat. DPFs have similar monolitic matrices but they have a LOT LOWER velocity to make the static attraction mechanism plate-out the soot. When a DPF "clogs", it only reduces the efficiency, meaning less soot is removed until it reaches equilibrium where it no longer removes it.

Back when i had the Crazy Rasberry Ant infestation in the AC of my car, I ran it for about 30 minutes with the heat on full high in summer sun to kill the ants. Once they stopped blowing out of the registers (CR Ants don't sting but I was getting SHOWERED with them).

Anyhow, I took it for a spin around the block and saw STRINGS of carbon being blown out of the cat.

DPFs are of two types: Ceramic or Sintered metal. Ceramic must be cleaned every 120,000 kilometers. Regeneration must occur every 500 Kilometers on the average depending on driving conditions and filter size. Just my 2 cents.

I am in contact with an engineer from DCL international-- he says he has a filter that would work, the SF8, but it costs almost $1500!

You can google "Mine-X" and "DCL" and get some info on this.

Maybe we can get them to go way down in price with a group buy? (laugh)

Mark

Mark

If you do buy one you want the sintered metal one. Apparently it last forever and is more thermally efficien than the ceramic one. The 09 has the metal!

You can extend cleaning time by mounting the DPF downstream from a DOC and mounting them both close to the turbo to get the heat for constant passive regeneration. Really wouldn't be that hard. Wonder how it would work.

Maybe "Active Regeneration" could be done by finding some way to squirt a little fuel between the DOC and the DPF after everything is good and hot about every 500 kilometers or x miles. Speculation of course, but someone should try this.

If you have a really efficient DOC and an EGR delete you could stimulate passive regeneration by the presence of more NOx which the DOC would convert to NO2 and burn the soot in the DPF. Passive reneneration relies on NO2 so I guess the more the merrier. The hotter they are the beter.

Does anyone have some technical documentation on VW DPF systems? Sensors used, Diagnostic procedures etc?