Gutting OEM N55 Downpipe

cjdzombie · 11-09-2017, 10:53 AM

I was wondering if anyone has gutted their OEM N55 downpipe (2011)? I have seen a few used for a decent price and thought about buying one to alter and keeping my original intact. I'm just wondering if the performance was just as good as any aftermarket catless downipe.

Mikaeldarer · 11-09-2017, 11:03 AM

Quote:

Originally Posted by cjdzombie

I was wondering if anyone has gutted their OEM N55 downpipe (2011)? I have seen a few used for a decent price and thought about buying one to alter and keeping my original intact. I'm just wondering if the performance was just as good as any aftermarket catless downipe.

Yes, this is the route I took and was very happy with results. Have had no issues with back pressure/throttle response and made good power with tune. I cannot compare to other catless DP's though as I have no experience with any.
Here are most recent logs if that helps: https://datazap.me/u/mikaeldarer/log...0&data=4-21-27

cjdzombie · 11-09-2017, 12:06 PM

Quote:

Originally Posted by Mikaeldarer

Yes, this is the route I took and was very happy with results. Have had no issues with back pressure/throttle response and made good power with tune. I cannot compare to other catless DP's though as I have no experience with any.
Here are most recent logs if that helps: https://datazap.me/u/mikaeldarer/log...0&data=4-21-27

Cool. What process did you use to clean out the cat material? Was it tricky with the angles in the pipe?

Mikaeldarer · 11-09-2017, 12:30 PM

Quote:

Originally Posted by cjdzombie

Cool. What process did you use to clean out the cat material? Was it tricky with the angles in the pipe?

Just used a flat head and hammer to break up the ceramic. Only took a few minutes.

rich_mane · 11-09-2017, 06:47 PM

I used a prybar and hammered it out of my old Acura RSX-S. Gave it a nice deeper exhaust note without spending any money

I have an oem downpipe for sale but it's not for an x-drive...

Ozzie335i · 11-09-2017, 08:43 PM

Why not just buy an aftermarket downpipe and keep the cat pipe in case you need it for an inspection?

AJL · 11-10-2017, 07:25 AM

Quote:

Originally Posted by Ozzie335i

Why not just buy an aftermarket downpipe and keep the cat pipe in case you need it for an inspection?

Because we don't do none of that fancy environmental stuff here in the FL

cjdzombie · 11-10-2017, 07:46 AM

Quote:

Originally Posted by AJL

Quote:

Originally Posted by Ozzie335i

Why not just buy an aftermarket downpipe and keep the cat pipe in case you need it for an inspection?

Because we don't do none of that fancy environmental stuff here in the FL

Same here in Ohio. No worries ob inspections here. I'm mainly looking for a for a cheap way to go catless, but a quality pipe with good fitment. I figure gutting a used OEM might be a good solution.

JETmn · 11-10-2017, 08:40 AM

A straight pipe is better than the stock pipe where it transitions in the middle, but it will still be miles better than with the cat in there.

Stage5Lurker · 11-11-2017, 02:07 AM

Quote:

Originally Posted by AJL

Quote:

Originally Posted by Ozzie335i

Why not just buy an aftermarket downpipe and keep the cat pipe in case you need it for an inspection?

Because we don't do none of that fancy environmental stuff here in the FL

Quote:

Originally Posted by AJL

Quote:

Originally Posted by Ozzie335i

Why not just buy an aftermarket downpipe and keep the cat pipe in case you need it for an inspection?

Because we don't do none of that fancy environmental stuff here in the FL

Stage5Lurker · 11-11-2017, 02:12 AM

I went with gutting the cat. Pretty easy to bang that stuff out. I havent had any issues. Pe mod, gutted cat, mhd I believe stage 2 93 oct. in the video.

cjdzombie · 12-26-2017, 03:32 PM

Bought an OEM downpipe today off of Ebay for $125. Looks to be in great condition. I'll be gutting it soon and installing sometime in Spring. Seems like a good price to go catless Stage 2. Looking forward to some more HP and volume with my MHD burbles.

Toome · 12-26-2017, 04:35 PM

Quote:

Originally Posted by cjdzombie

Bought an OEM downpipe today off of Ebay for $125. Looks to be in great condition. I'll be gutting it soon and installing sometime in Spring. Seems like a good price to go catless Stage 2. Looking forward to some more HP and volume with my MHD burbles.

Unfortunately the burbles are very quiet even with a catless dp. They still need to add an intensity slider for the N55 app.

EB89 · 12-26-2017, 05:54 PM

Quote:

Originally Posted by Toome

Unfortunately the burbles are very quiet even with a catless dp. They still need to add an intensity slider for the N55 app.

You need to do more than the downpipes to hear the burbles.

PE Exhaust and they are loud as hell

mike@x-ph.com · 12-27-2017, 01:45 PM

An Aftermarket catless downpipe will have a better air flow.
That being said if the used one you found is really cheap, go for it

cjdzombie · 12-31-2017, 09:17 AM

I wonder if the shape of a gutted oem pipe would have much of a noticeable difference compared to an aftermarket. I noticed that the Wagner catless downpipe has a larger diameter like the oem.

dleccord · 01-03-2018, 12:27 PM

Can you partially gut the OEM for a "catted" version instead of completely gutting it? trying to avoid any raspy-ness

cjdzombie · 01-10-2018, 07:40 PM

I gutted the downpipe this evening. The process was pretty simple. I just used a 1" paddle drill, hammer and long screw driver. Took maybe 15 minutes. I still have 2 stubborn studs to get out. Then I'll be ready to do the install swap.

dleccord · 01-11-2018, 03:31 AM

Quote:

Originally Posted by cjdzombie

I gutted the downpipe this evening. The process was pretty simple. I just used a 1" paddle drill, hammer and long screw driver. Took maybe 15 minutes. I still have 2 stubborn studs to get out. Then I'll be ready to do the install swap.

Post videos of sound after install?

DrRobert · 01-11-2018, 11:20 AM

I gutted an OEM DP and had a HJS HFC retrofitted into it. Works great, stealth mod.

cjdzombie · 02-08-2018, 04:50 PM

Big wrench in the plan. My brother-in-law trashed the flanges while trying to remove the remaining studs. The gutted pipe is out of the picture. Guess I'm back in the market for a downpipe.

xxMike61 · 02-08-2018, 06:54 PM

Quote:

Originally Posted by cjdzombie

Big wrench in the plan. My brother-in-law trashed the flanges while trying to remove the remaining studs. The gutted pipe is out of the picture. Guess I'm back in the market for a downpipe.

They were just rust welded on there that bad or what happened?

11-09-2017, 10:53 AM	#1
cjdzombie First Lieutenant 76 Rep 290 Posts Drives: 2011 E92 335i xDrive, M Sport Join Date: Dec 2015 Location: Cincinnati iTrader: (0)	Gutting OEM N55 Downpipe I was wondering if anyone has gutted their OEM N55 downpipe (2011)? I have seen a few used for a decent price and thought about buying one to alter and keeping my original intact. I'm just wondering if the performance was just as good as any aftermarket catless downipe. __________________ 2011 E92 335i xDrive M-Sport MHD 93 Stage 2+ \| xHP Stage 3 \| xDelete \| Catless Downpipe \| Phoenix Racing Intercooler \| ARM CP \| AFE Drop In Filter
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11-09-2017, 06:47 PM	#5
rich_mane First Lieutenant 139 Rep 227 Posts Drives: 2011 E92 335i Join Date: Jan 2016 Location: S.FL iTrader: (1)	I used a prybar and hammered it out of my old Acura RSX-S. Gave it a nice deeper exhaust note without spending any money I have an oem downpipe for sale but it's not for an x-drive...
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11-09-2017, 08:43 PM	#6
Ozzie335i Lieutenant Colonel 659 Rep 1,525 Posts Drives: 2011 335i Join Date: Aug 2014 Location: DFW iTrader: (1)	Why not just buy an aftermarket downpipe and keep the cat pipe in case you need it for an inspection?
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11-10-2017, 08:40 AM	#9
JETmn Lieutenant Colonel 245 Rep 1,595 Posts Drives: 2011 335i xDrive Msport Join Date: Apr 2013 Location: Orlando iTrader: (0) Garage List 2011 335Xi [0.00]	A straight pipe is better than the stock pipe where it transitions in the middle, but it will still be miles better than with the cat in there. __________________ 2011 335Xi 6AT - VRSF catless DP - VRSF 7" FMIC with turbo inlet pipe - VRSF chargepipe - Pure Stage 1 turbo - JB4 - E30 - xHP Stage 3 - Strongflex tension bushings - Whiteline RSFB - UUC rear swaybar
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11-11-2017, 02:12 AM	#11
Stage5Lurker Private First Class 45 Rep 158 Posts Drives: White Buffalo Join Date: Oct 2015 Location: Kirkland, WA iTrader: (0) Garage List 2012 BMW LCI e92 33 ... [10.00]	I went with gutting the cat. Pretty easy to bang that stuff out. I havent had any issues. Pe mod, gutted cat, mhd I believe stage 2 93 oct. in the video.
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12-26-2017, 03:32 PM	#12
cjdzombie First Lieutenant 76 Rep 290 Posts Drives: 2011 E92 335i xDrive, M Sport Join Date: Dec 2015 Location: Cincinnati iTrader: (0)	Bought an OEM downpipe today off of Ebay for $125. Looks to be in great condition. I'll be gutting it soon and installing sometime in Spring. Seems like a good price to go catless Stage 2. Looking forward to some more HP and volume with my MHD burbles. __________________ 2011 E92 335i xDrive M-Sport MHD 93 Stage 2+ \| xHP Stage 3 \| xDelete \| Catless Downpipe \| Phoenix Racing Intercooler \| ARM CP \| AFE Drop In Filter
	Appreciate 0 Quote

12-27-2017, 01:45 PM	#15
mike@x-ph.com BimmerPost Supporting Vendor 24199 Rep 190,807 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	An Aftermarket catless downpipe will have a better air flow. That being said if the used one you found is really cheap, go for it __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
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12-31-2017, 09:17 AM	#16
cjdzombie First Lieutenant 76 Rep 290 Posts Drives: 2011 E92 335i xDrive, M Sport Join Date: Dec 2015 Location: Cincinnati iTrader: (0)	I wonder if the shape of a gutted oem pipe would have much of a noticeable difference compared to an aftermarket. I noticed that the Wagner catless downpipe has a larger diameter like the oem. Attached Images __________________ 2011 E92 335i xDrive M-Sport MHD 93 Stage 2+ \| xHP Stage 3 \| xDelete \| Catless Downpipe \| Phoenix Racing Intercooler \| ARM CP \| AFE Drop In Filter
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01-03-2018, 12:27 PM	#17
dleccord Captain 99 Rep 840 Posts Drives: 2011 BMW 335i E90 Join Date: Apr 2016 Location: Nelson, New Zealand iTrader: (0)	Can you partially gut the OEM for a "catted" version instead of completely gutting it? trying to avoid any raspy-ness
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01-10-2018, 07:40 PM	#18
cjdzombie First Lieutenant 76 Rep 290 Posts Drives: 2011 E92 335i xDrive, M Sport Join Date: Dec 2015 Location: Cincinnati iTrader: (0)	I gutted the downpipe this evening. The process was pretty simple. I just used a 1" paddle drill, hammer and long screw driver. Took maybe 15 minutes. I still have 2 stubborn studs to get out. Then I'll be ready to do the install swap. __________________ 2011 E92 335i xDrive M-Sport MHD 93 Stage 2+ \| xHP Stage 3 \| xDelete \| Catless Downpipe \| Phoenix Racing Intercooler \| ARM CP \| AFE Drop In Filter
	Appreciate 0 Quote

01-11-2018, 11:20 AM	#20
DrRobert Normal Person 148 Rep 862 Posts Drives: 2011 E90 335i Join Date: May 2014 Location: paradise iTrader: (0) Garage List 2011 E90 335i [0.00]	I gutted an OEM DP and had a HJS HFC retrofitted into it. Works great, stealth mod.
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02-08-2018, 04:50 PM	#21
cjdzombie First Lieutenant 76 Rep 290 Posts Drives: 2011 E92 335i xDrive, M Sport Join Date: Dec 2015 Location: Cincinnati iTrader: (0)	Big wrench in the plan. My brother-in-law trashed the flanges while trying to remove the remaining studs. The gutted pipe is out of the picture. Guess I'm back in the market for a downpipe. __________________ 2011 E92 335i xDrive M-Sport MHD 93 Stage 2+ \| xHP Stage 3 \| xDelete \| Catless Downpipe \| Phoenix Racing Intercooler \| ARM CP \| AFE Drop In Filter
	Appreciate 0 Quote