Replacing DPF CR TDI with aftermarket passive unit.

Has anyone on here replaced their failing DPF with a different passive unit?

I have helped design an aftertreatment system for a small turbo diesel engine, and we used a completely passive filter in conjunction with a catalyst, and ended up with some pretty sweet results.

My TDI only has about 40K on it, but I'm looking ahead and weighing my options. I would like to increase the power and economy of my car as well and I am thinking that adding a higher flowing DPF in conjuction with a tune it could really make a difference.

I am aware of the options, aka deleting it all together or just living with what I have, at this point I'm not interested in that stuff and would just like to hear about what others have done.

I found this company, Diesel Emissions Technologies, and they are an aftermarket that produces these filters, mainly for trucks, but still I could make one work. I have welder and a fair amount of expience with stuff like this so fabrication isn't a problem. Find a filter at a decent price and a calibration that wil work best with the different filter is what I am most interested in!

I would think that most will either stay with the stock dpf or delete it altogether.

Not trying to be a jerk, but seriously did you read what I wrote? I said I am familar with those options and not interested in them at the moment.

You asked if anyone here had done this. I just answered your question. I have been here a while and have never read of anyone trying this. Moving on.

What others have done is clean it, leave it, replace it with oem, or delete it...

I must be the one other weirdo thinking of this I have gone so far as look at retro fit programs and what VW offers in Europe. The retro fit programs are exclusively truck and bus, and shipping a passive DPF from EU along with the part cost is rediculous. I would actually be interested in installing a DPF on my PD if the tuning work can be sorted out.

Like LightFlyer1 and DieselRacer already said - most will stay OEM or delete.

Jason

EDIT: I was just thinking about what you would need - a differential pressure sensor across the DPF, a temperature probe, a fuel injector to help light off the burn off, and an ECM to control it. It maybe easier to have it stand alone, like a turbo timer, than adding functions to the EDC.

SilverGhost said:

I must be the one other weirdo thinking of this I have gone so far as look at retro fit programs and what VW offers in Europe. The retro fit programs are exclusively truck and bus, and shipping a passive DPF from EU along with the part cost is rediculous. I would actually be interested in installing a DPF on my PD if the tuning work can be sorted out.

Like LightFlyer1 and DieselRacer already said - most will stay OEM or delete.

Jason

EDIT: I was just thinking about what you would need - a differential pressure sensor across the DPF, a temperature probe, a fuel injector to help light off the burn off, and an ECM to control it. It maybe easier to have it stand alone, like a turbo timer, than adding functions to the EDC.

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THANK YOU! Someone who wants to participate in the discussion.

Would you really need all of that though? The DI TDIs burn pretty hot, so having an EGT gauge to monitor that would be essential. But other than that as long as you are in the specified temperature range for the filter you choose then I don't see a need for an extra injector or a standalone system at all. Maybe I am thinking of the system too simply, but even if you weren't burning off everything a lot of the sytems, like the one I posted, are cleanable.

With a couple v-band clamps welded on each end it would be a 10 minute job to unistall the DPF so service would not be bad. Sending it out to be cleaned would not be ideal but worst case scenario it happens once every 2 years depending on usage. Also most of the units I am considering are meant for trucks. As long as the VW can get the DPF up to temperature, I see having a larger DPF can only benifit the system in terms of flow and capacity.

The biggest draw to this is avoiding high cost of replacment with a unit that may not last very long. I do a decent amount of shorter trips so I could be replacing them more often than most. Having a unit that I can service, ultimately resulting in a longer life and it cost's less than the VW one would just be the best of everything.

http://www.emitec.com/en/home.html

Emitec is the company that I have used before, and we never used any type of burn off procedure or anything of the sort. This engine does not get continual use as it was a project I did in college, so that does have a lot to do with it. I still do wonder if it can be done with just a DPF delete file and in place of the active DPF put a passive. I also was under the impression that the reason it was called a passive unit is because the nature of how it works without extra components needed to induce burn off.

Found a bit more info:

Passive regeneration: By coating the inlet-side of the filter with a catalyst (precious metals) the soot can be reduced by using the vehicle’s own exhaust heat. For optimum performance, Engine Control Systems currently recommends using this DPF type with engine exhaust temperatures that hit the 280 degree Celsius range for at least 25% of the duty cycle. If the engine does not reach these temperatures, then the filter will clog on a regular basis and will have to be removed and regenerated on a cleaning machine that has heating capabilities. Engines that want to use this technology must first have temperature data loggers installed to measure the exhaust temperature for 3-5 days to verify the product will work. This is required by CARB and most of the manufacturers. These passive DPF systems are more economical than active regeneration DPF types, and usually cost around $7,000-$10,000, depending on the engine size.

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That price is quite high, and I'm not sure where that number is coming from. I'm going to look around a bit more and see if I can come up with a ball park price, because for me that is the biggest hurdle with this idea at the moment.

lorge-

Interesting idea you have. I assume you would do away with the post-burn process? Is your thought process to use a DPF to only capture the crud coming out of the engine? I'm by no means an expert on these complex exhaust systems so my questions may seem off the mark. Finding a DPF from another vehicle/truck would be tricky to retro-fit into your VW. Wonder what the Chevy Cruze is using for their clean diesel? Anyway, good luck with it.

Its an interesting idea. I believe you have a emissions test in new York would a passive/flow thru cell or any other type of dpf other than a closed cell active dpf actually pass emissions testing. New York has the same standards as California I think and one would assume that if the alternate dpf designs which all to my knowledge are less effective than the oem style would pass the requirments VW or virtually any other manufacturer would have gone that route. Now if you were elsewhere without testing or were retrofitting an older diesel than definitely be an interesting idea. I've seen the retrofit kits for off road equipment so its a matter of scale I guess.

From what read the passive system that VW retrofits in EU, the efficiency was only about 60% compared with the active system on on ours that is nearer to 95-98%. Also there was a caution against its use if the vehicle is primarily used in short trips.

Basically unless you did mostly hiway driving and/or had common sense to know that if you did any amount of city style driving that you would have to take it on a hiway drive, ITS NOT FOR YOU.

The active system would only activate if needed on this setup. But you need to have it if you do any amount of stop and go or don't get the DPF up to temp regularly (50-200 miles?)

Jason

If you're talking about a purely passive regenerating DPF...

You'd need sustained DPF temps of around 650F to regenerate it passively, which is pretty hard to do unless you have mountains to climb or trailers to tow. Just cruising down the highway won't get it quite hot enough, so I'd be concerned about soot accumulation during extended periods of light load or with frequent short trips.

VW actually has a passive system for ALH applications, too. Not sure what the recommendations are for that one.

The existing system already does a passive regen cycle, so isn't the real question whether you could use a catalyst and tune out the active regen? I think they also do a mandatory active regen from time to time.. so if you could use the catalyst and tune it to only do active when backpressure, etc. requires one, that might be the best of all worlds.

Passive regeneration - The act of regen taking place without the use of engine mounted components due to engine load being high enough to produce required exhaust gas temps

Active regeneration - A regen taking place due to dpf differential pressure being high and the engine using any of the following to increase exhaust temps to clean the filter - Intake throttle valve, exhaust back pressure valve, VGT turbo, after-treatment fuel injection(using base injectors or exhaust mounted injector).

patbob said:

The existing system already does a passive regen cycle, so isn't the real question whether you could use a catalyst and tune out the active regen? I think they also do a mandatory active regen from time to time.. so if you could use the catalyst and tune it to only do active when backpressure, etc. requires one, that might be the best of all worlds.

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And then we end up building a system that, in effect, is what VW already designed for the CR. They try to balance enough safe gaurds against stupid people with MPG, longevity, effectiveness, etc.

Jason

SilverGhost said:

And then we end up building a system that, in effect, is what VW already designed for the CR. They try to balance enough safe gaurds against stupid people with MPG, longevity, effectiveness, etc.

Jason

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After much research and some more thought this is basically what I was thinking. It really IS NOT WORTH IT.

To recap:

The main goal of this 'upgrade' would be 2 fold.

1. Eliminate the need for service of DPF.

2. Allow for higher flow, for increased power without dramatically increasing particulate shooting out the tail pipe.


The problem is, I was mistaken in thinking that passive DPFs need to be serviced less. As many of you have pointed out, you need sustained high temps in order to properly use one. If you do not have this then there is a good chance it will need replacement sooner rather than later. Only simple solution here to oversize the unit so it has a very large capacity and maybe come up with a simple way to increase EGTs post motor, without changing the ECU calibration.

That leads to other problems. Mostly, cost and time. To me all of that work is not worth it, when you can just replace the OEM unit, maybe it will last longer than I think.

I still am interested in achieving #2. I'm thinking of making up a boost activated bypass valve for the filter, aka just add a wastegate post turbo, pre DPF that simply bypasses it. Will it increase emissions emmitted, yeah, but only for periods of high boost, or when I need the exhaust flow the most. Still not totally sure that would work, just because I might risk wasting the peak EGT time, when I'm doing an active regen.


I just like being different and also to tinker. So no need to be hostile, sure just leave it alone is the easiest answer, but where's the fun in that?

This sounds like a complicated and expensive pipe dream with no real reward.

Doing all of this isn't going to get you more power without also upgrading the turbocharger. You can probably upgrade the turbocharger without doing all of this (or delete the DPF or install a larger DPF). Why do all of this crazy stuff that won't comply with emissions when you're done anyway?

Long story short, the DPF isn't the power-limiting factor in the equation; the turbo and head design are.

VeeDubTDI said:

This sounds like a complicated and expensive pipe dream with no real reward.

Doing all of this isn't going to get you more power without also upgrading the turbocharger. You can probably upgrade the turbocharger without doing all of this (or delete the DPF or install a larger DPF). Why do all of this crazy stuff that won't comply with emissions when you're done anyway?

Long story short, the DPF isn't the power-limiting factor in the equation; the turbo and head design are.

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I pretty much agreed with your first statement in my last post......

But if the the DPF is not the limiting factor then why are their tunes out there that increase power output dramatically with removal of the DPF?

A stage 2 without DPF delete and a stage 2 with DPF delete are only about 5 horsepower difference. I wouldn't consider that a dramatic increase in power output.

Rather than try to reengineer the entire DPF system, the real win here would probably be to design an aftermarket DPF filter that works with the system as-is, but has a filter element that's easily removable for cleaning by an average amateur mechamic. Even if the element has to smaller and therefore cleaned more often, a few cleanings to the tune of hundreds of $ will still be a win over replacing the OEM with another OEM.

I suspect the reason VW didn't do this is that it would make temporary DPF deletes too easy (the gooberment probably wouldn't let them).

Over the road truckers have removable ones that can be cleaned. I guess the great unwashed masses couldn't be trusted to comply.

The real reason seems to be that they need to be tucked up as close to the turbo outlet as possible to make the most use of the heat already there. In our cars and the methods used that means a really cramped tight space to fit in.

patbob said:

Rather than try to reengineer the entire DPF system, the real win here would probably be to design an aftermarket DPF filter that works with the system as-is, but has a filter element that's easily removable for cleaning by an average amateur mechamic. Even if the element has to smaller and therefore cleaned more often, a few cleanings to the tune of hundreds of $ will still be a win over replacing the OEM with another OEM.

I suspect the reason VW didn't do this is that it would make temporary DPF deletes too easy (the gooberment probably wouldn't let them).

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For something that needs to be done every 200,000 miles (estimated), is it even worth it? You can clean the existing DPF, it just requires a bit of work to get it out, but certainly saves a lot of money over buying and installing a brand new one.

VeeDubTDI said:

For something that needs to be done every 200,000 miles (estimated), is it even worth it? You can clean the existing DPF, it just requires a bit of work to get it out, but certainly saves a lot of money over buying and installing a brand new one.

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and we are ALL waiting to see that! Actually pulling it and cleaning it with the commensurate delays in shipping etc...and then Re-installing it. First guy that does it hopefully will chime in.

And when you don't close-couple the DPF, you need a lot more fuel, and then get things like the 6.4 liter DPF fires.

VeeDubTDI said:

For something that needs to be done every 200,000 miles (estimated), is it even worth it? You can clean the existing DPF, it just requires a bit of work to get it out, but certainly saves a lot of money over buying and installing a brand new one.

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I believe the professional cleaning services need the element removed from the container, and since ours are welded into theirs, that may take some doing. DIY cleaning may, or may not, be good enough.

As far as worth it, consider resale value as these cars age, and that most buyers won't have the skills to clean a DPF so will need the mechanic to do it.. and how much that will cost them.

patbob said:

I believe the professional cleaning services need the element removed from the container, and since ours are welded into theirs, that may take some doing. DIY cleaning may, or may not, be good enough.
As far as worth it, consider resale value as these cars age, and that most buyers won't have the skills to clean a DPF so will need the mechanic to do it.. and how much that will cost them.

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The DPF cleaning company that was at TDIFest last year made no such indication of the filter matrix needing to be removed from the housing prior to sending it to them.

http://www.dpfregeneration.com/

Other options...

Is there any chance that the in car cleaning solutions can work for the DPF's? Or are they only for soot load and not ash? I thought about starting a thread about this, but this one seems pretty active so:
I noticed that Aaron at Bora is selling a cleaning kit for shops to use: http://shopping.boraparts.com/product_info.php?products_id=1485
Also this kit from Bardahl seems pretty stout for cleaning the DPF in the vehicle. They only seem to sell this in Europe. Going through the pressure sensors seems scary and genius at the same time:
https://www.youtube.com/watch?v=VbXGwAWHxWM
And Finally here is a youtuber either soaping up the engine internally or cleaning out the DPF:
https://www.youtube.com/watch?v=7Q_kTw5N1tA

I wouldn't expect good results, but it might work. There are a bunch of videos on YouTube of people doing it in Europe... no idea how long it lasts, though.

Guys look at DPF like this: they are job security for mechanics! Can you imagine ripping off a DPF from a VW that's been in the northern states? All rusted, crusty, etc. sounds like fun!

200k & then I'll either get a new Passat or a Cummins 6-speed manual.

Would it not be possible to run some sort of electric heating element or even a fuel based heating element that runs the fuel, gases, etc separate tot eh engines system, so the soot and dirty fuel does not end up in the engine oil or back through the turbo?