[TDIwyse]

Originally Posted by DWR

If we wanted a diesel DOC ... oh wait, we had one. Why did we get rid of it?
Not sure where this conversation is going...

Some history:

http://www.e90post.com/forums/showpo...0&postcount=57

Gutting out internals in our experience made for outragous turbocharger deviation. In some cases the tips of the compressor wheel broke off and the turbo was junk. We conculded that as the empty DPF created such a low pressure result... like a plenum chamber the boost could not be controlled.. hence why we developed the downpipe/software..

If someone can get us an original downpipe from USA.... we will make one to the same spec as UK/EU models.

I sent mine over there for their example. After getting my DPF back from over yonder I ran with it gutted for awhile until my "free" downpipe from them showed up. I didn't push things very hard though with just the gutted canister... but having that DOC in place sure made a big difference on the smell after the first ~minute of operation.

And after all the fussing around to pull/reinstall/pull the OEM canister with the requirement to remove the engine mount... the much smaller/lighter downpipe is wonderfully simple to install/remove. I don't want to put that big OEM thing back in there... but maybe hacking/welding it into the SCR area could be done. Would take some creative welding/shaping of metal though ...

Edit: Had forgotten the post #51 they showed a downpipe with a high flow catalyst right at the turbo outlet...

[Yozh]

Originally Posted by DWR

If we wanted a diesel DOC ... oh wait, we had one. Why did we get rid of it?
Not sure where this conversation is going.

iaknown, do you still have your stock downpipe? I'm thinking some testing is in order. I am volunteering my services.

I'm running a stock DOC on mine without a DPF. The smell was very well controlled with the SCR cat still in place, but I had to get rid of it due to fouling. Now, with just a DOC, the smell is a little more, but a large improvement over the straight pipe. I do note that stock DOC is quite small (short), but may be that is all that's needed.

[DWR]

Originally Posted by Yozh

I'm running a stock DOC on mine without a DPF. The smell was very well controlled with the SCR cat still in place, but I had to get rid of it due to fouling. Now, with just a DOC, the smell is a little more, but a large improvement over the straight pipe. I do note that stock DOC is quite small (short), but may be that is all that's needed.

Yozh, that is really interesting. The first reference that I am aware of (that's not saying much) that the SCR affects the smell. Must be doing something other than NOX reduction.

[GreekboyD]

Hey iaknown. What's the latest word on the production for your exhaust build?

[TDIwyse]

Used DWR's Torque pids to record the 3 exhaust probe temps on the way to work (deadlines ... work really gets in the way of life sometimes...). This is with the ecotune downpipe that has bungs for all 3 oem egt probes. Thought it would be interesting in regards to cats and lightoff temps.

Example of a ~58 mph steady state condition when going slightly uphill and into a stiff headwind, and then at idle after sitting parked for ~15 seconds.

[BB_cuda]

Originally Posted by TDIwyse

Used DWR's Torque pids to record the 3 exhaust probe temps on the way to work (deadlines ... work really gets in the way of life sometimes...). This is with the ecotune downpipe that has bungs for all 3 oem egt probes. Thought it would be interesting in regards to cats and lightoff temps.

Example of a ~58 mph steady state condition when going slightly uphill and into a stiff headwind, and then at idle after sitting parked for ~15 seconds.

Interesting that there is ~ 20°F gradient (from preDOC EGT to preSCR EGT) in both the 58 mph and sitting parked cases. Big difference is ~150°F fall off from cruising to parked/idle condition.

This would be in the direction of being a hack but there is that tape stuff (fiberglass?)applied to exhausts to get the underbody temp down. It would correspondingly keep the heat within the pipe. Primary application that I've seen is on exhaust headers. I'm sure its on summit or other hotrod affiliated websites. Not sure how much the idle temps would be pulled up.

For the better case scenario, 458F=236C this reacts the carbon monoxide at a "okay rate 80%" but the hydro carbon rate is real low still (25%). Which of these contributes to the stink? Let's be honest here, we aren't trying to get back to full scrubbing or we would have never done anything to our cars. We after the stink aren't we?

Back to my question related to 2 way versus 3 way cat discussion now started. I had found the 200 cell with heavier reactants in it versus normal 200 cell hi flow, if you recall. I had wondered if the $30 was worth it in terms of better scrubbing. Prior to reading above, I had presumed the comparison i was trying to do was same catalytic process but more of it. Another layer of the onion to peel off now .......

[iaknown]

Originally Posted by GreekboyD

Hey iaknown. What's the latest word on the production for your exhaust build?

I am told it is next on the jig at the manufacturer. That being said it could still be months before we get a prototype confirmed and it goes to production. But we have something in the works in the meantime to get an exhaust out to you guys while this one gets made.....

[DWR]

Originally Posted by BB_cuda

This would be in the direction of being a hack but there is that tape stuff (fiberglass?)applied to exhausts to get the underbody temp down. It would correspondingly keep the heat within the pipe. Primary application that I've seen is on exhaust headers. I'm sure its on summit or other hotrod affiliated websites. Not sure how much the idle temps would be pulled up.

For the better case scenario, 458F=236C this reacts the carbon monoxide at a "okay rate 80%" but the hydro carbon rate is real low still (25%). Which of these contributes to the stink? Let's be honest here, we aren't trying to get back to full scrubbing or we would have never done anything to our cars. We after the stink aren't we?

Back to my question related to 2 way versus 3 way cat discussion now started. I had found the 200 cell with heavier reactants in it versus normal 200 cell hi flow, if you recall. I had wondered if the $30 was worth it in terms of better scrubbing. Prior to reading above, I had presumed the comparison i was trying to do was same catalytic process but more of it. Another layer of the onion to peel off now .......

I like the way you are thinking BB_cuda.

While I do not have temperature data, I can attest to ability of header wrap and ceramic coatings to keep the heat in. I was able to get a Corbra (sports car not Mustang) to pass new car emissions with the cats just in front of the rear axle by using these 2 methods. To be honest, the best part was a cooler transmission tunnel. While we are add it, how about a blanket on the turbine housings? I have seen some really amazing heat insulation done with mineral wool and 'glass blankets.

Carbon monoxide is orderless. So, it is the HCs and PMs we need to address.

[BB_cuda]

Blankets are a whole new art form for spacecraft. Fiberous insulation with internal reflective layers are effective at atmospheric pressure where as multi layer insulation (MLI) is best for on orbit with vacuum pressure. MLI is pretty poor at ambient pressure.

[fsd350]

After spending a lot of time on here and contacting a couple of our preferred vendors some of you suggested, I will be doing the alphabet delete soon. I hadn't thought about the SCR catalyst itself. Is clogging a big issue? Any success with hollowing it out? I was planning on keeping all my stock components and DDE around in case I have to revert back to stock. Should I budget for an exhaust now as well? Thanks guys.

[BB_cuda]

Depends how much $$$ you want to spend at a time. Most of us have taken things a step at a time. One person gutted the SCR but he had unintentionally been sooting up his SCR quicker than the norm. Another went about 15000 miles and then gutted after seeing 9 psi delta pressure across SCR from soot. I'm at 6000 miles post DPF and budgeting for exhaust in next 5000 to 6000 miles. If you chunk the exhaust while doing the pipe, save yourself hassle and look into porting the turbo wastegate before pipe goes on. There is an alternative to porting but as far as I know only the knowledgeable TDI has went there with external wastegate. We've all been learning since late 2013 with things picking up more so this year.

[fsd350]

Good to know that I can wait a while on the exhaust. If it was not that weird oval shape I would probably weld a Magnaflow in place of the SCR and be done. That rearmost Nox sensor bung will no longer be necessary right? I have seen some exhaust pics on here where the sensor is still in place. I think I will take your suggestion and port the wastegate while I am in there. Seems the consensus is 9/16".

[Yozh]

Originally Posted by fsd350

That rearmost Nox sensor bung will no longer be necessary right? I have seen some exhaust pics on here where the sensor is still in place. I think .

If your re-tune is done properly, you will not need either of the NOx sensors. Mine are completely removed and unplugged from the harness and do not throw any errors.

[BB_cuda]

I put oil pan bolts of proper size in where NOX sensors were before. I think they are M20x1.5. Careful on my memory of the pitch though. The banned one helped me out on this. The rear spot bottomed out on the bolt so I had to shorten it.
EDIT: I checked my notes and the NOX bung is threaded M20X1.5. The Ecotune pipe doesn't have the lip in it so a normal length one will work there. I forget if banned one had the NOX bung in his pipe but if yes, it shouldn't have a lip in it.

[iaknown]

Originally Posted by fsd350

Good to know that I can wait a while on the exhaust. If it was not that weird oval shape I would probably weld a Magnaflow in place of the SCR and be done. That rearmost Nox sensor bung will no longer be necessary right? I have seen some exhaust pics on here where the sensor is still in place. I think I will take your suggestion and port the wastegate while I am in there. Seems the consensus is 9/16".

You're probably referring to my exhaust which has a rear bung and sensor in it....As stated it is unnecessary if the tune is done correctly, I just did mine this way early on, but it's totally optional.

[fsd350]

Thanks for your help guys. I'll be ordering my DP from the banned one this week and sending 2 DDE's to Jarek. Can't wait for the mods to begin!

[rspring]

Buzzken is working on a full turbo back setup too. He will have DPs by the end of next week, hopefully. I queried Rawtek this week, but they have no plans for our cars.

[kydiesel35]

Originally Posted by fsd350

Thanks for your help guys. I'll be ordering my DP from the banned one this week and sending 2 DDE's to Jarek. Can't wait for the mods to begin!

Agreed, in the same boat as you are.

[Persian Whisperjet]

I'm coming up on 4.000 miles from shedding my 70 ugly pounds. Does anyone have a sense of how much longer before my SCR unit starts to get clogged up and if there is some way to monitor that process in BMWhat? Thanks in advance.

[Persian Whisperjet]

Some 8K miles after installing Jarek Stage I it was time.

The hardest part was... reloading the MIG welder when it an out of wire. In other words, easy day. Three hours, done.

Turbo whistle is more pronounced but nothing obnoxious.

[temporaptor]

Nice gut job, but those welds are ugly. Did you use the proper stainless wire and shielding gas?

[BB_cuda]

I had the same question about whether or not he used 300 series wire. I don't have the needed tri gas either but do have 308SS wire.
Hey atleast the welding will be on the top side where no one can see it. If you used normal steel filler wire, make sure to put some high temp paint on it to keep from rusting.