[Chief Orman]

Can't stand the smell of my DPF delete exhaust. Recommendation on a downpipe with a cat that won't break the bank.

[Megs335]

Whitbread can weld a cat in any downpipe, give him a shout. Once the cat is warm, it makes a very nice difference.

[Chief Orman]

Originally Posted by Megs335

Whitbread can weld a cat in any downpipe, give him a shout. Once the cat is warm, it makes a very nice difference.

any more off the shelf solutions?

[dmanb2b]

Originally Posted by Chief Orman

any more off the shelf solutions?

ATM catted dp, also sold by Whitbread. I have one...dealing with him was great.

Most cost effective is to gut dpf and leave doc in place

[Ken Oath]

Originally Posted by dmanb2b

ATM catted dp, also sold by Whitbread. I have one...dealing with him was great.

Most cost effective is to gut dpf and leave doc in place

Is it not more economical to remove the DPF, replace it with a downpipe with a CAT and then sell the intact DPF with remaining life?

Also gutting the DPF would make it hard to set the turbo geometry as the turbo would bounce off the limiter.

[dmanb2b]

Originally Posted by Ken Oath

Is it not more economical to remove the DPF, replace it with a downpipe with a CAT and then sell the intact DPF with remaining life?

Also gutting the DPF would make it hard to set the turbo geometry as the turbo would bounce off the limiter.

DPF doesn't have much value in the states and in fact some have even given theirs away . We have at least two members running a gutted dpf with DOC in place and no turbo issues that I am aware of. One is on a stage 2 and the other on stage 2.8.

What specific turbo geometry and limiter are you speaking of?

[dmanb2b]

Chief, just also remember a cat will help significantly, but is won't be odor free...smells like an early 2000's CDI Mercedes with cat.

[Ken Oath]

The VNT map controlling the turbo acceleration would be hard to adjust.
Maybe with the DOC intact it would be ok but not if the DPF is completely gutted.

[dmanb2b]

Originally Posted by Ken Oath

The VNT map controlling the turbo acceleration would be hard to adjust.
Maybe with the DOC intact it would be ok but not if the DPF is completely gutted.

Thanks. I am no expert, so I appreciate the information and always willing to learn, but wouldn't a gutted DPF be same as running an uncatted downpipe, both having very little back-pressure?

[Ken Oath]

With a downpipe you have a laminar flow of exhaust gases, with a gutted DPF you have a massive void and turbulent flow.

[TDIwyse]

Originally Posted by Ken Oath

The VNT map controlling the turbo acceleration would be hard to adjust.
Maybe with the DOC intact it would be ok but not if the DPF is completely gutted.

Just curious ... since the R2S sequential twin turbo system in our M57 cars does not use VNT (Variable Nozzle Turbos) technology, why would we have a VNT map in the DDE to control the turbo acceleration?

I ran with a partially gutted DPF (the DOC still being in place) for awhile and did not see any boost/EMP issues. Others on here have ran much longer than I did without issues. The one LARGE advantage of using a downpipe is that you can get it in/out without removing the motor mount, which is required when pulling that pig of a DPF/DOC out of the car.

Even with a good downpipe, the turbine exit/transition on our LP turbo is horribly turbulent as the turbine exit is off-center from the exhaust housing. And then when the wastegate opens right next to the turbine under high output conditions, you'll get even worse turbulent airflow as all those gases are flowing into that off-center area and mixing violently.

Would be interesting to get measured data on a gutted DPF with DOC in place versus a downpipe with cat to see if there's much difference between boost/EMP behavior.

[dmanb2b]

Originally Posted by TDIwyse

Would be interesting to get measured data on a gutted DPF with DOC in place versus a downpipe with cat to see if there's much difference between boost/EMP behavior.

I can help with data on a catted dp, if you tell me which parameters you want me to measure in Torquepro.

I also just spoke to the gentleman that I sold my DPF to. He is running it completely gutted, ie with no DOC in place on a JR 2.8, with no issues.

[TDIwyse]

Originally Posted by dmanb2b

I can help with data on a catted dp, if you tell me which parameters you want me to measure in Torquepro.

I also just spoke to the gentleman that I sold my DPF to. He is running it completely gutted, ie with no DOC in place on a JR 2.8, with no issues.

In TestO the parameters I'd suggest looking at would be:
STAT_Exh_pTrbnUs_full_WERT (Exhaust Manifold Pressure = EMP)
STAT_LADEDRUCK_SOLL_WERT (Boost Pressure Set/Desired)
STAT_LADEDRUCK_WERT (Boost Actual/Measured)

If the DDE can't control the boost properly you would see STAT_LADEDRUCK_WERT being much different than STAT_LADEDRUCK_SOLL_WERT.

The relationship between EMP and Boost (EMP/Boost) also gives insight into the post turbine flow and if the gutted DPF would be worse than a downpipe or a downpipe with a cat. Of course you'd want that test to be while measuring power output. Then comparing the measured power levels and logged parameters could point you to the differences with any of those combinations.

[aaddam2]

not to take this thread left...but i would assume you are only getting the smell when in city traffic correct? I plan on deleting soon and plan on going no cat. i have mixed driving on my route but most of the time im moving would smell really be an issue?

[rbreding]

Originally Posted by aaddam2

not to take this thread left...but i would assume you are only getting the smell when in city traffic correct? I plan on deleting soon and plan on going no cat. i have mixed driving on my route but most of the time im moving would smell really be an issue?

As long as you are moving forward instead of reverse then yes no worries.

[digitaldav]

Im not sure what your bank has in it but this is the one I have been using from AARodriguez.
Buzzken - BMW 335D DPF Delete Kit - 3"

$749.00
SKU:
SKU-489D5901

[Chief Orman]

Originally Posted by aaddam2

not to take this thread left...but i would assume you are only getting the smell when in city traffic correct? I plan on deleting soon and plan on going no cat. i have mixed driving on my route but most of the time im moving would smell really be an issue?

Originally Posted by aaddam2

not to take this thread left...but i would assume you are only getting the smell when in city traffic correct? I plan on deleting soon and plan on going no cat. i have mixed driving on my route but most of the time im moving would smell really be an issue?

correct... smell is only an issue when parked in traffic but it is just annoying as hell. No odor when moving.

[lnxguy]

Get in touch with Ken, his cats are great.

[Miko226]

Originally Posted by lnxguy

Get in touch with Ken, his cats are great.

I'm likely getting Ken's DOC downpipe soon.

These diesels smell worse than any deleted truck I've smelt

[auntulna]

I have the full alphabet delete with only a small cat put in by Matt Whitbread.

The smell is pretty strong sitting or moving slow, a good deal more than my 2005 Passat TDI, which has only a cat but a bigger one than the 335d.

My understanding is that the bigger, more expensive cat converter you get, there will be less smell. Is that right?

[Davll]

I have the Buzzken with DOC. Probably the best you can do while deleted for smell.

[Chief Orman]

just ordered the full ATM catted down pipe and exhaust. Not trusting my POS Bulgarian crap exhaust is not leaking...the crap down pipe was too long any way...