[Hoooper]

Reason I suggest looking deeper at it is experience on other vehicles. On some 3.5L cars (naturally aspirated) only making around 300 HP/300 lb ft at the crank a 3" exhaust was a huge improvement over 2.5". Based on the fact that a 335D with a DPF delete and tune is going to be making more like 350HP+/550lbft+, seems like bigger than 3" would be helpful. Exhaust sizing seems to be a bit of a black art though

[Puerto Rican 335d]

where the hell is TIAGO didnt he do a 3'' exhaust on his car if anyone can enlighten us would be him since he lives in europe

[iaknown]

Originally Posted by Hoooper

Reason I suggest looking deeper at it is experience on other vehicles. On some 3.5L cars (naturally aspirated) only making around 300 HP/300 lb ft at the crank a 3" exhaust was a huge improvement over 2.5". Based on the fact that a 335D with a DPF delete and tune is going to be making more like 350HP+/550lbft+, seems like bigger than 3" would be helpful. Exhaust sizing seems to be a bit of a black art though

Yea, there are a lot of variables going on here. Turbo cars are more efficient than naturally aspirated. Diesels are much more efficient at low rpms compared to gas, we are not spinning the rpms gas cars are so we are not moving the same volume of air relative to displacement.

Not to mention there are drag cars out there going 8 seconds through a single 3" exhaust. "Black art" is a good way to describe it but I personally am not going to sweat going larger than 3".

[Ajs_435d]

Yeah would be good to know if removing mufflers etc with dpf delete will yield power over just a dpf delete?

[GreekboyD]

Originally Posted by ajs_335d

Yeah would be good to know if removing mufflers etc with dpf delete will yield power over just a dpf delete?

Mufflers alone weigh 40 pounds I heard. I'd think something turbo-back would yield more power out of a more restrictive OEM set-up.

[BayE30]

Originally Posted by Hoooper

bug ecotune about getting their tune to trick the monitors. If they did that, you could get away with it in CA. It really shouldnt be that hard either if they just made the attempt. Once you get past the OBD test, its just visual on diesel and there is no way the smog tech would notice the DPF delete since the turbos pretty much block the above view and the undertray blocks the below view.

which monitors would need to be simulated? EGR, DPF, what else? i would LOVE to delete EGR, DPF, and DEF. then add meth, an aggressive tune, and straight pipe turbo back. these cars would be rocket ships.

[GreekboyD]

Originally Posted by SF335DIESEL

which monitors would need to be simulated? EGR, DPF, what else? i would LOVE to delete EGR, DPF, and DEF. then add meth, an aggressive tune, and straight pipe turbo back. these cars would be rocket ships.

You'd need an LSD after all that...lol

[BB_cuda]

Originally Posted by GreekboyD

This one?:

Link

Nope, not that one. That guy sold his car. The thread I'm remembering is in the last 3-4 months~ish. It came out around sane time TDI was beginning to experiment with his exhaust. Perhaps the pic is embedded in TDI's thread. I'll go dig that up.

[TDIwyse]

Originally Posted by GreekboyD

Mufflers alone weigh 40 pounds I heard. I'd think something turbo-back would yield more power out of a more restrictive OEM set-up.

As I was hacking my system apart I had a desire to keep the squashed midpipe shape all the way to the back for a single exhaust output right in the middle. But I kept the dual exhaust setup for simplicity.

Mufflers with a little bit of extra pipe ... ~40 lbs.

http://www.e90post.com/forums/showpo...3&postcount=20

It appears to me from the data I've collected, as well as reading about the adaptations the system does from the BMW documentation, that if the DDE sees the system making the requested torque output it wants at the rpm it wants without triggering any panics (like EGT's) ... making the intake and exhaust less restrictive won't help make more power. At least not long term. The car will adapt the air/fuel parameters and adjust its internal settings to account for changes in the system.

http://www.micro-tronik.com/learning...ctronics-dde7/

For Diesel Electronics DDE7, there are four adaptations for various functions:
· Adaptation of mass air flow meter
· Mean quantity adaptation
· Adaptation of EGR valve
· Adaptation of swirl-flap actuator

From the data I've gathered, the major bottleneck in the exhaust was the DPF, then the DOC inside the same canister as the DPF. Removing the DPF was a huge improvement to the sustained power levels so that the EGT level didn't start impacting the fueling (if it gets too high the DDE starts defueling to protect the system, unless someone pulls that from the DDE in a remap ... which wouldn't be good for the long term health of your vehicle).

I do really like the sound of the car though now that the mufflers are gone and the downpipe is in place. Very throaty and some turbo whistle... I still have the SCR in place and have been a little hesitant to remove that as the youtube video's of complete straight pipe 335d's didn't sound like something I'd like. Your personal tastes may be different from mine.

[335dlci]

Originally Posted by TDIwyse

As I was hacking my system apart I had a desire to keep the squashed midpipe shape all the way to the back for a single exhaust output right in the middle. But I kept the dual exhaust setup for simplicity.

Mufflers with a little bit of extra pipe ... ~40 lbs.

http://www.e90post.com/forums/showpo...3&postcount=20

It appears to me from the data I've collected, as well as reading about the adaptations the system does from the BMW documentation, that if the DDE sees the system making the requested torque output it wants at the rpm it wants without triggering any panics (like EGT's) ... making the intake and exhaust less restrictive won't help make more power. At least not long term. The car will adapt the air/fuel parameters and adjust its internal settings to account for changes in the system.

http://www.micro-tronik.com/learning...ctronics-dde7/

For Diesel Electronics DDE7, there are four adaptations for various functions:
Adaptation of mass air flow meter
Mean quantity adaptation
Adaptation of EGR valve
Adaptation of swirl-flap actuator

From the data I've gathered, the major bottleneck in the exhaust was the DPF, then the DOC inside the same canister as the DPF. Removing the DPF was a huge improvement to the sustained power levels so that the EGT level didn't start impacting the fueling (if it gets too high the DDE starts defueling to protect the system, unless someone pulls that from the DDE in a remap ... which wouldn't be good for the long term health of your vehicle).

I do really like the sound of the car though now that the mufflers are gone and the downpipe is in place. Very throaty and some turbo whistle... I still have the SCR in place and have been a little hesitant to remove that as the youtube video's of complete straight pipe 335d's didn't sound like something I'd like. Your personal tastes may be different from mine.

Speaking of SCR intact..is tune still use the scr system or did you drain your tanks?

[TDIwyse]

Originally Posted by 335dlci

Speaking of SCR intact..is tune still use the scr system or did you drain your tanks?

Urea tanks drained soon after tune, added distilled water to flush it, re-drained ... have been empty for a >10k miles now. Having said that, I have not data specifically showing the urea injector was or was not fully coded off.

[iaknown]

Originally Posted by TDIwyse

As I was hacking my system apart I had a desire to keep the squashed midpipe shape all the way to the back for a single exhaust output right in the middle. But I kept the dual exhaust setup for simplicity.

Mufflers with a little bit of extra pipe ... ~40 lbs.

http://www.e90post.com/forums/showpo...3&postcount=20

It appears to me from the data I've collected, as well as reading about the adaptations the system does from the BMW documentation, that if the DDE sees the system making the requested torque output it wants at the rpm it wants without triggering any panics (like EGT's) ... making the intake and exhaust less restrictive won't help make more power. At least not long term. The car will adapt the air/fuel parameters and adjust its internal settings to account for changes in the system.

http://www.micro-tronik.com/learning...ctronics-dde7/

For Diesel Electronics DDE7, there are four adaptations for various functions:
· Adaptation of mass air flow meter
· Mean quantity adaptation
· Adaptation of EGR valve
· Adaptation of swirl-flap actuator

From the data I've gathered, the major bottleneck in the exhaust was the DPF, then the DOC inside the same canister as the DPF. Removing the DPF was a huge improvement to the sustained power levels so that the EGT level didn't start impacting the fueling (if it gets too high the DDE starts defueling to protect the system, unless someone pulls that from the DDE in a remap ... which wouldn't be good for the long term health of your vehicle).

I do really like the sound of the car though now that the mufflers are gone and the downpipe is in place. Very throaty and some turbo whistle... I still have the SCR in place and have been a little hesitant to remove that as the youtube video's of complete straight pipe 335d's didn't sound like something I'd like. Your personal tastes may be different from mine.

Would alteration of the mass air signal help overcome adaptation? The AEM is sounding better and better.....

[335dlci]

Originally Posted by TDIwyse

Urea tanks drained soon after tune, added distilled water to flush it, re-drained ... have been empty for a >10k miles now. Having said that, I have not data specifically showing the urea injector was or was not fully coded off.

Interesting. I have access to the special tool that is used to exchange "old" urea that could be possibly used. Edit: Found the SIB that shows the tool http://www.e90post.com/forums/attach...1&d=1303262242

[TDIwyse]

Originally Posted by iaknown

Would alteration of the mass air signal help overcome adaptation? The AEM is sounding better and better.....

Possibly, if you do it in such a way that it doesn't trigger a plausibility error. The DDE is balancing a lot of information from the various sensors.

[dzlmoose]

Originally Posted by BB_cuda

Greek, you are definitely a mind reader. I still haven't found that guy's post of the all 3" SS exhaust. Axle asked him how much and he said $800 and Axel got same quoted for ~$550 if i have my facts straight. It was about 3 months ago, i believe. He had it done in Maryland. I think he had either 4.25" or 4.5" diameter exhaust tips.

Maybe a road trip to Maryland for exhaust and VAC (Quaife). I almost sure I could find a good custom exhaust fabricator in Houston or at least Texas before I put 3000 miles on the car though.

Quaife is on the list but at a lower priority.

I have the link to the thread I think your looking for I pmd you.

[arayz]

I have straight pipes right after DP sounds like a v8 with turbo whistle, if the cat is 3" u wont get more power by adding 4", just do a straight pipe 3"

I have over 400 hp without meth, havent dynoed it jet with met but i think i end up with 500

[austinla335d]

HP figures aren't good data points for exhaust size comparison, ie 2.5->3 yields 'x' increase, so 3->3.5 yields 'y'. CFM restriction is the concern, but on our cars it's not as high as you'd think.
Low rpm means low CFM by comparison to a high RPM car, turbocharged especially (obviously). 3" would be plenty if unhindered. 3" splitting to two 2.5" even better.

Ecotune wouldn't be interested in intentionally deceiving the EPA. Remember, "off-road use only" is basically legal for "you can't sue us for misusing our product". No reason to help you pass smog in an off-road only setup.

[GreekboyD]

Originally Posted by austinla335d

HP figures aren't good data points for exhaust size comparison, ie 2.5->3 yields 'x' increase, so 3->3.5 yields 'y'. CFM restriction is the concern, but on our cars it's not as high as you'd think.
Low rpm means low CFM by comparison to a high RPM car, turbocharged especially (obviously). 3" would be plenty if unhindered. 3" splitting to two 2.5" even better.

Ecotune wouldn't be interested in intentionally deceiving the EPA. Remember, "off-road use only" is basically legal for "you can't sue us for misusing our product". No reason to help you pass smog in an off-road only setup.

Why do you think this would be better?

[BB_cuda]

Originally Posted by dzlmoose

I have the link to the thread I think your looking for I pmd you.

Moose, thanks for PM but that was same thread Greek provided for me. Cssns did that mod a long time ago. Perhaps other fellow is who I'm remembering. Arayz, did you post your exhaust pics in the last say 6 months?

[Puerto Rican 335d]

yeah whatever happened to chris

[BB_cuda]

Originally Posted by Puerto Rican 335d

yeah whatever happened to chris

Presuming Chris= cssnms, he sold his car. He was concerned that emissions, injectors, DDE, etc were going to eat his lunch so he sold before trouble started. I think his D had mid 30,000 miles on it if I recall correctly. He had a DPF delete on it though I thought. Can someone confirm? I would want to hear from whomever bought it for long term DPF delete performance and reliability. Maybe we can dig up Chris to find buyer for us and get a report.

[GreekboyD]

Originally Posted by BB_cuda

Presuming Chris= cssnms, he sold his car. He was concerned that emissions, injectors, DDE, etc were going to eat his lunch so he sold before trouble started. I think his D had mid 30,000 miles on it if I recall correctly. He had a DPF delete on it though I thought. Can someone confirm? I would want to hear from whomever bought it for long term DPF delete performance and reliability. Maybe we can dig up Chris to find buyer for us and get a report.

I don't believe he had a DPF delete. He must still lurk from time to time. Nice guy with good info whenever I'd PM him.