335d New Custom Exhaust Installed - Review - Page 2 - BMW 3-Series (E90 E92) Forum

hotrod2448 · 11-17-2011, 07:21 AM

Quote:

Originally Posted by 335dM

Just a bit concerned about the airflow without the OEM mufflers ?

Mufflers actually make very little difference in flow on most modern vehicles. Now if you were to rip out the DPF and cats then you might need to be concerned about getting the car tuned to run properly but, I don't see there being any real issues with this setup.

cssnms · 11-17-2011, 07:22 AM

The oem mufflers are very restrictive. airflow is much better now. I can actually feel air coming out of the tip with some force.

hotrod2448 · 11-17-2011, 11:02 AM

Quote:

Originally Posted by cssnms

The oem mufflers are very restrictive. airflow is much better now. I can actually feel air coming out of the tip with some force.

No disrespect here but, I don't believe the hand-o-mometer version of the anemometer. I don;t doubt that it's an improvement but, I don't think it's anything huge. It likely feels like considerably more flow because there isn't this cavernous muffler to slow down the flow of the gas before exiting the pipe anymore.

Are you going to do before and after dyno runs?

cssnms · 11-17-2011, 11:24 AM

The handometer isn't a precise measurment tool admittedly. However the difference in cfm's is very noticeable. Just as noticeable as if you were to hold your hand in front of your a/c vent and turn the fan from low to high. Now whether or not the improved flow will account for a power difference remains to be seen. I already have a before dyno, plan to do a follow up as soon as the car is out of the shop.

hotrod2448 · 11-17-2011, 01:11 PM

I haven't looked at it but it would be cool if the BT tool could log the exhaust pressure sensor. I know it's way upstream reading pre and post DPF but, still there should be something visible there if you are altering exhaust flow enough to matter.

335dM · 11-17-2011, 04:25 PM

Quote:

Originally Posted by 335dM

Just a bit concerned about the airflow without the OEM mufflers ?

I meant aerodynamic airflow

hotrod2448 · 11-17-2011, 05:35 PM

Quote:

Originally Posted by 335dM

I meant aerodynamic airflow

335i guys have been doing it for a long time with no apparent ill effects.

If you wanted to go all out you could probably make a diffuser type panel to cover the void.

335dM · 11-18-2011, 09:49 AM

Quote:

Originally Posted by hotrod2448

Quote:

Originally Posted by 335dM

I meant aerodynamic airflow

335i guys have been doing it for a long time with no apparent ill effects.

If you wanted to go all out you could probably make a diffuser type panel to cover the void.

Thats exactly what I was thinking about because this set up have huge aeronydamic issue under the car!

cssnms · 11-18-2011, 10:28 AM

Quote:

Originally Posted by 335dM

Thats exactly what I was thinking about because this set up have huge aeronydamic issue under the car!

Not sure, haven't seen a reduction in mpg's or any unsafe handling characteristcs at speeds of up to 120mph, but in any event if it bothers you it is easily addressable with a cover or rear diffusor.

cssnms · 11-18-2011, 10:32 AM

Quote:

Originally Posted by hotrod2448

I haven't looked at it but it would be cool if the BT tool could log the exhaust pressure sensor. I know it's way upstream reading pre and post DPF but, still there should be something visible there if you are altering exhaust flow enough to matter.

Agree. Another way to look at it is via a reduction in EGT's. If back pressure is reduced so is the heat build-up and as such doing a before and after EGT reading should show some improvement (reduction) in EGT's. Unfortunately the BT scan tool will not work with LCI cars so one cannot get full benefit from the tool. BT is working on a software update, but it's likely going to be many months.

BillyG335d · 11-21-2011, 06:00 AM

I think the new exhaust looks great and congrats on being the first I have seen to have the balls to go for it! I assume you do not have the Add-Blue connected to your set up. How will that effect emissions and warranty? I would love to see the look on the Mechanics face when you take it to the shop for the next oil change!

What's next??? Custom Intake??? After that sick exhaust I can't imagine what kind of intake you are going to come up with.

cssnms · 11-21-2011, 08:24 AM

Quote:

Originally Posted by BillyG335d

I think the new exhaust looks great and congrats on being the first I have seen to have the balls to go for it! I assume you do not have the Add-Blue connected to your set up. How will that effect emissions and warranty? I would love to see the look on the Mechanics face when you take it to the shop for the next oil change!

What's next??? Custom Intake??? After that sick exhaust I can't imagine what kind of intake you are going to come up with.

Thanks Bill.

How's the "d" running? You sell those wheels/tires yet?

The DEF (AdBlue) system is still connected. None of the emissions systems equipment was touched so the warranty should be a-okay!

As for what's next, I am not really sure,,, given the emissions obstacles and lack of viable options at the moment to tune/delete the DPF etc it's limited.

I have considered an in-take, but I would want a true cold-air intake because I believe that's the only way to realize any gains and that is going to take some time to figure out. Aside from improved sound, there isn't a whole lot to be gained with just a regular intake. Not only have in-takes been shown in many cases to reduce power but more often than not they let a lot more shit into the engine because they don't filter as well as the stock air box. Check-out Mr-5's dyno testing with the AFE in-take and then after he designed his own cold-air intake. The expensive AFE cone filter intake caused his car to lose power! Something like the "Mr-5 intake" is along the lines of what I am thinking.

cssnms · 03-11-2012, 02:01 PM

Alas some video....

cssnms · 03-12-2012, 10:08 AM

For anyone that is interested in a comparison between a turbo-back (no dpf) exhaust and a dpf back exhaust w/all catalysts in place, the link below will take to a test conducted by Diesel Power Magazine.

It is interesting to note that while the dpf does supress sound it is not as restrictive as many thought.

http://www.dieselpowermag.com/tech/d...s/viewall.html

plantationwalrus · 03-12-2012, 06:01 PM

Those are some purdy welds! *golf clap*

cssnms · 09-20-2012, 08:01 AM

Up for those pm'ing me about my exhaust.

There is a sound clip in here too. Still no dyno though, but now that the temps are cooling down I will get back to the shop to get that follow-up dyno done.

Puerto Rican 335d · 09-20-2012, 12:21 PM

Chris hurry up damn it. I did my dynos its your turn, LOL!!!!! BTW I havent done the latest dyno for the RENNtech UPGRAE, but will do so maybe soon!!

FormerRotor · 09-21-2012, 04:11 PM

Quote:

Originally Posted by cssnms

Up for those pm'ing me about my exhaust.

There is a sound clip in here too. Still no dyno though, but now that the temps are cooling down I will get back to the shop to get that follow-up dyno done.

Quote:

Originally Posted by Puerto Rican 335d

Chris hurry up damn it. I did my dynos its your turn, LOL!!!!! BTW I havent done the latest dyno for the RENNtech UPGRAE, but will do so maybe soon!!

Three cheers to both of you gents for that. Let's see them Dynos.

03-11-2012, 02:01 PM	#35
cssnms Brigadier General Drives: 2011 BMW 335d Join Date: Sep 2010 Location: Murland Posts: 3,098 iTrader: (4)	Alas some video.... Attached Images

09-20-2012, 12:21 PM	#39
Puerto Rican 335d Captain Drives: Montego Blue 335d Join Date: Jun 2011 Location: Puerto Rico Posts: 957 iTrader: (0)	Chris hurry up damn it. I did my dynos its your turn, LOL!!!!! BTW I havent done the latest dyno for the RENNtech UPGRAE, but will do so maybe soon!! __________________ RENNtech Flash/WAGNER IC VMR710 19"/Execuhitch Hitch/Koni FSD Soft Ride Bike Rack Amsoil Cetane Boost Diesel Fuel Additive Amsoil Diesel Fuel Additive Concentrate

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11-17-2011, 07:22 AM	#24
cssnms Brigadier General Drives: 2011 BMW 335d Join Date: Sep 2010 Location: Murland Posts: 3,098 iTrader: (4)	The oem mufflers are very restrictive. airflow is much better now. I can actually feel air coming out of the tip with some force.

11-17-2011, 11:24 AM	#26
cssnms Brigadier General Drives: 2011 BMW 335d Join Date: Sep 2010 Location: Murland Posts: 3,098 iTrader: (4)	The handometer isn't a precise measurment tool admittedly. However the difference in cfm's is very noticeable. Just as noticeable as if you were to hold your hand in front of your a/c vent and turn the fan from low to high. Now whether or not the improved flow will account for a power difference remains to be seen. I already have a before dyno, plan to do a follow up as soon as the car is out of the shop.

11-17-2011, 01:11 PM	#27
hotrod2448 grand poobah Drives: E90 335d AW, E70 X5 SG Join Date: Dec 2006 Location: Charlotte, NC Posts: 2,003 iTrader: (0) Garage List 2011 335d [0.00]	I haven't looked at it but it would be cool if the BT tool could log the exhaust pressure sensor. I know it's way upstream reading pre and post DPF but, still there should be something visible there if you are altering exhaust flow enough to matter.

11-21-2011, 06:00 AM	#33
BillyG335d DIESEL POWER Drives: 2011 BMW 335d Join Date: Jun 2010 Location: Delaware Posts: 77 iTrader: (0)	I think the new exhaust looks great and congrats on being the first I have seen to have the balls to go for it! I assume you do not have the Add-Blue connected to your set up. How will that effect emissions and warranty? I would love to see the look on the Mechanics face when you take it to the shop for the next oil change! What's next??? Custom Intake??? After that sick exhaust I can't imagine what kind of intake you are going to come up with.

03-12-2012, 10:08 AM	#36
cssnms Brigadier General Drives: 2011 BMW 335d Join Date: Sep 2010 Location: Murland Posts: 3,098 iTrader: (4)	For anyone that is interested in a comparison between a turbo-back (no dpf) exhaust and a dpf back exhaust w/all catalysts in place, the link below will take to a test conducted by Diesel Power Magazine. It is interesting to note that while the dpf does supress sound it is not as restrictive as many thought. http://www.dieselpowermag.com/tech/d...s/viewall.html

03-12-2012, 06:01 PM	#37
plantationwalrus uʍop ǝpısdn Drives: '11 335d, SG/Saddle, ZSP, ZPP Join Date: Nov 2011 Location: South bay area, NorCal Posts: 52 iTrader: (0)	Those are some purdy welds! golf clap

09-20-2012, 08:01 AM	#38
cssnms Brigadier General Drives: 2011 BMW 335d Join Date: Sep 2010 Location: Murland Posts: 3,098 iTrader: (4)	Up for those pm'ing me about my exhaust. There is a sound clip in here too. Still no dyno though, but now that the temps are cooling down I will get back to the shop to get that follow-up dyno done.