[locolobo]

I'm waiting on my downpipe while considering Iaknown's complete system to go with that. I really don't want to gut the SCR, in case I decide to sell the car someday in factory configuration. Is it possible to have a pipe fabricated to go between the downpipe flange and then into a Y to connect to the existing mufflers? Obviously round pipe is used in complete systems. I have a shop in mind to ask, but wondering if anyone's done it that way.

[rulonger]

I quoted the fabrication of a mid-pipe, but felt it best to wait for a full solution. I have not gutted my SCR and have about 4.5 K miles since the tune / Bohl dp install. I feel I am driving a ticking time bomb as it relates to clogging up the SCR.

[locolobo]

rulonger how much was the quote? If you can say. I'm not in too big a hurry because I haven't made any changes yet. And my pipe hasn't arrived yet so I'm still planning. I guess a complete system is preferred due to not having to make any cuts.

[NC335d]

A couple of quick questions for the OP. How many miles do you put on your car. Are you doing the alphabet delete to make the car more reliable or for additional power?

Basically, you should be able to run your car for a good 6k-8k miles without worrying about clogging you SCR, just make sure you disconnect the DEF. Also depends on your driving style, the more you get on the skinny peddle the more soot you are going to produce, hence the quicker your SCR will get clogged.

If you can wait it out just get iaknowns system or go with the CircuitWerkz system and have a local muffler place modify it. The only thing you will really need off of your old exhaust would be the flange connecting the downpipe to the rest of the factory exhaust.

[locolobo]

How many miles do you put on your car: 10 K per year, 60% city

Are you doing the alphabet delete to make the car more reliable or for additional power?

Both reliability and power, maybe even a bit more fuel economy on the highway.

I am considering the complete system - I saw tonight's "update." But I'm probably going to wait and do it all at once. Why tune now and plug up the SCR?

[Persian Whisperjet]

You can probably make a bypass pipe but it's tricky -- the pile into the SCR is a sort of flat oval shape.

[locolobo]

Yeah I see the problem with the oval shape. But at the downpipe outlet and the muffler inlets it's round.

[Persian Whisperjet]

When I had not changed out my SCR but post-DPF and tune, I'd floor it occasionally and it was like I had my old 300D again -- big cloud of filth.

[OmahaDZL]

Im in the same situation kinda...

One of my turbo seals failed, so Im having stage 3 turbos put in to replace the stocks... but with iaknowns exhaust not available... I dont want to clog up the SCR...but... with the mechanic already being right there, why wouldnt I just have them put on the DP instead of putting back the DPF....

I dunno what to do .... How much work is it putting the downpipe in after everything has been loose recently?

[iaknown]

Originally Posted by OmahaDZL

Im in the same situation kinda...

One of my turbo seals failed, so Im having stage 3 turbos put in to replace the stocks... but with iaknowns exhaust not available... I dont want to clog up the SCR...but... with the mechanic already being right there, why wouldnt I just have them put on the DP instead of putting back the DPF....

I dunno what to do .... How much work is it putting the downpipe in after everything has been loose recently?

You definitely want to put the downpipe in, don't be putting the dpf back in. The SCR/midpipe is what you need to make a decision on...

[OmahaDZL]

Originally Posted by iaknown

You definitely want to put the downpipe in, don't be putting the dpf back in. The SCR/midpipe is what you need to make a decision on...

Well thats good to know....its not worth that effort to swap them later I assume? ...ie...harder than a couple of bolts while its on a rack....

Alright...point me to a midpipe...i havent seen one available, only talk of one...ie...have an exhaust shop or Jess do the work of fab'ing one up.... And the midpipe would have to bolt to.... aftermarket catback right? Not the stock exhaust.....now we are just getting into more components.... Ive been trying to avoid that. Id rather gut my SCR than have to buy a midpipe and a 335i exhaust.... and fight to get all that fitment right..

[Persian Whisperjet]

If you have a grinder and a welder gutting the SCR is not difficult.

[Thecastle]

Just an opinion.....

With the diesel scandal from VW, I suspect its a matter of time before all gasoline emissions testing states also being testing diesels. Heck their already cracking down on tucks (semi's).

I would think its better to keep the emissions stuff intact (but stored somewhere) for the future if you need an inspection or want to sell the car to someone who wants/needs an emissions complaint car. thats why I hesitate on gutting the SCR myself, might need it again.

[floydarogers]

I question whether you mean SCR or DPF when talking about "gutting".
There are two catalyst canisters on these cars: the DPF/Oxydation catalyst (which is where a DP would go), and the SCR Catalyst (which is just in front of the rear axle where a resonator would go).

I suspect you actually mean DPF.

[tek4tex]

Originally Posted by OmahaDZL

Well thats good to know....its not worth that effort to swap them later I assume? ...ie...harder than a couple of bolts while its on a rack....

Alright...point me to a midpipe...i havent seen one available, only talk of one...ie...have an exhaust shop or Jess do the work of fab'ing one up.... And the midpipe would have to bolt to.... aftermarket catback right? Not the stock exhaust.....now we are just getting into more components.... Ive been trying to avoid that. Id rather gut my SCR than have to buy a midpipe and a 335i exhaust.... and fight to get all that fitment right..

Go ahead and got the SCR it's the most cost efficient solution that allows maintaining the stock higher quality stainless exhaust that is more corrosion resistant. I don't think the states will have the money to measuring tailpipe emissions but you could always get a spare down the road

[locolobo]

I went ahead with it; it was the lowest cost and immediate option. I will keep an eye out at salvage yards for a used 335d exhaust or SCR catalyst. In the meantime my tune is running very well, the sound is excellent, power is awesome. The only downside is the increased smell especially when backing into my garage.

[serpa4]

I'd like a mid pipe delete also incase I move or need to sell to emission state. If you gut, its as good as a delete? I.e. the tune designed with the SCR filter removed is just as happy with a gutted one? I'd think so. I didn't think of a junk yard to replace if required. Guess that would be the cheapest option.
How do you gut one? Cut open, remove, weld closed?
Can't a muffler shop make a oval tube or not that simple? The guys at BPC said it might be from $200 to $500 for them to custom make one from the turbo back to y-pipe where it is round again (haven't looked myself). Seems like $200 is good to go, but $500 is a lot.

[larrysing]

Originally Posted by Thecastle

Just an opinion.....

With the diesel scandal from VW, I suspect its a matter of time before all gasoline emissions testing states also being testing diesels. Heck their already cracking down on tucks (semi's).

I would think its better to keep the emissions stuff intact (but stored somewhere) for the future if you need an inspection or want to sell the car to someone who wants/needs an emissions complaint car. thats why I hesitate on gutting the SCR myself, might need it again.

It won't happen in Texas. Too many diesel passenger trucks "rolling coal" and those owners, some who have spent THOUSANDS on their mods, will not allow that law to pass in Texas.

[floydarogers]

Originally Posted by larrysing

It won't happen in Texas. Too many diesel passenger trucks "rolling coal" and those owners, some who have spent THOUSANDS on their mods, will not allow that law to pass in Texas.

When the US EPA starts fining TX $100K+ per day for not meeting air quality standards because their testing is crap, who do you think will blink?

[DWR]

Originally Posted by floydarogers

When the US EPA starts fining TX $100K+ per day for not meeting air quality standards because their testing is crap, who do you think will blink?

The vehicles have to pass Federal air quality standards, not the States the vehicles drive in. That's why enforcement at the state level varies so much.

[floydarogers]

Originally Posted by DWR

The vehicles have to pass Federal air quality standards, not the States the vehicles drive in. That's why enforcement at the state level varies so much.

This is not the whole story. The EPA also checks REGIONAL air quality, and forces the locals to tighten up on pollution sources. So, if DFW or Houston started to fail air quality standards (I believe Houston is close, mostly due to refineries), the local counties/cities have to begin mandated checks of polluting sources, including automobiles.

For instance, only automobiles in the Seattle area of WA state (possibly also Lewis county down near Portland) have to pass emissions tests, because only the Seattle Metro area has problems meeting standards. Although, the state also banned field burning in E. WA due to it causing PM10 emissions problems.

[DWR]

You are correct. It is controlled regionally, with measurements taken in urban areas.

So, lets get down to brass tacks.

Our vehicles are in the LDDV column. Right off you can see PM emisions have no specification. That's not until Tier III phases in, starting next year. Because these are idle emissions, Total Hydrocarbons is not likely to be an issue with a diesel, with or without a cat. Even NOx is not likely to be a problem due to low combustion temps at idle.

In generally, the EPA does not like to fine states. It is just counterproductive. Corporations bear the brunt of the EPA's ire. If you are in Houston, EPA is focusing on industrial sources, not vehicles. Moreover, the fact is the gross majority of fines come from judicial actions, not administrative.

Having said the above, "rolling coal" on public highways could change all that. It has become a form of road aggression that is getting the notice of law enforcement. In many states, having visible emissions can give you the priviledge of an involuntary tow and fine.