2010 2011 BMW 5 Series Forum F10
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
 

2010 2011 BMW 5 Series Forum F10 F10 Technical Topics Engine, Transmission, Exhaust, Drivetrain, ECU Software Modifications OEM gutted cat vs catless downpipe.
Post Reply
 
Thread Tools Search this Thread
      09-13-2018, 01:13 PM   #1
Bts535i
Private
7
Rep
58
Posts

Drives: 2012 535i xdrive
Join Date: Sep 2018
Location: New York

iTrader: (0)

OEM gutted cat vs catless downpipe.

2012 535i xdrive pwg.
new to mods and BMW's.
just got my jb4 and I wanna go to map 2..
what's the performance difference between a gutted cat and catless downpipe
Appreciate 0
      09-13-2018, 02:41 PM   #2
Shieldze1025
Keepin' America Free
Shieldze1025's Avatar
United_States
70
Rep
1,260
Posts

Drives: F10 535i
Join Date: Dec 2009
Location: Haleiwa, HI

iTrader: (7)

It's minor, but an aftermarket catless DP has a smoother path for the air to travel. You probably would not even notice a difference, but I recommend buying a purpose built catless DP.

However, if you gut your stock one there's no going back. I fully plan on swapping mine back to stock before selling it.
__________________
F10 535i | Retired: E60 ///M5 | E92 335i

"If everything seems under control, you're not going fast enough"
-Mario Andretti
Appreciate 1
      09-13-2018, 02:49 PM   #3
Bts535i
Private
7
Rep
58
Posts

Drives: 2012 535i xdrive
Join Date: Sep 2018
Location: New York

iTrader: (0)

Quote:
Originally Posted by Shieldze1025 View Post
It's minor, but an aftermarket catless DP has a smoother path for the air to travel. You probably would not even notice a difference, but I recommend buying a purpose built catless DP.

However, if you gut your stock one there's no going back. I fully plan on swapping mine back to stock before selling it.
Quote:
Originally Posted by Shieldze1025 View Post
It's minor, but an aftermarket catless DP has a smoother path for the air to travel. You probably would not even notice a difference, but I recommend buying a purpose built catless DP.

However, if you gut your stock one there's no going back. I fully plan on swapping mine back to stock before selling it.

I was going to buy a used one from a friend for 150$ gut that one and keep my stock one instead of almost 600 for the catless dp..
the cheaper dp I've herd fitment issues with and no mounts
Appreciate 1
      09-13-2018, 03:00 PM   #4
lsturbointeg
Lieutenant General
lsturbointeg's Avatar
United_States
9149
Rep
14,522
Posts

Drives: 2011 535i Jet Black
Join Date: Aug 2014
Location: Asian lost in OH

iTrader: (0)

are you just punching out the OEM pipe? i'm actually intrigued on how that's done as I've heard fitment issues with aftermarket DP's.
__________________
~F90Conversion~21"3Piece Forged AvantGardeWheels~KWV1Coilovers~CQUENCE slotted/drilled rotors~GoodridgeStainlesslines~MeisterschaftQuadEx haust~Akrapovic 4"tips~VRSF DP~VRSF CP~TurboSmart BOV~K&N filter~CarbonFiberExteriorComponents~GladenAlphaCo mponents~MatchUp7BMW~Punch P300-12T~
Follow me on Instagram: lsturbointeg
Appreciate 0
      09-13-2018, 03:22 PM   #5
Bts535i
Private
7
Rep
58
Posts

Drives: 2012 535i xdrive
Join Date: Sep 2018
Location: New York

iTrader: (0)

Quote:
Originally Posted by lsturbointeg View Post
are you just punching out the OEM pipe? i'm actually intrigued on how that's done as I've heard fitment issues with aftermarket DP's.
Quote:
Originally Posted by lsturbointeg View Post
are you just punching out the OEM pipe? i'm actually intrigued on how that's done as I've heard fitment issues with aftermarket DP's.

yea... I'll just punch it out..
Appreciate 0
      09-13-2018, 04:31 PM   #6
Shieldze1025
Keepin' America Free
Shieldze1025's Avatar
United_States
70
Rep
1,260
Posts

Drives: F10 535i
Join Date: Dec 2009
Location: Haleiwa, HI

iTrader: (7)

Quote:
Originally Posted by Bts535i View Post
I was going to buy a used one from a friend for 150$ gut that one and keep my stock one instead of almost 600 for the catless dp..
the cheaper dp I've herd fitment issues with and no mounts
Go for it. I just waited for one to show up in the classifieds and found a really nice used Dr. Euro catless DP for $300.
__________________
F10 535i | Retired: E60 ///M5 | E92 335i

"If everything seems under control, you're not going fast enough"
-Mario Andretti
Appreciate 0
      09-14-2018, 09:16 AM   #7
Janzen
Registered
0
Rep
1
Posts

Drives: GT 535i
Join Date: Sep 2018
Location: Finland

iTrader: (0)

So, what would be required from the software side, with a Catless DP so not to get any error messages?
Appreciate 0
      09-17-2018, 06:33 PM   #8
Shieldze1025
Keepin' America Free
Shieldze1025's Avatar
United_States
70
Rep
1,260
Posts

Drives: F10 535i
Join Date: Dec 2009
Location: Haleiwa, HI

iTrader: (7)

Quote:
Originally Posted by Janzen View Post
So, what would be required from the software side, with a Catless DP so not to get any error messages?
You'll get a CEL for excessive emissions but besides the dash light bothering you, it's not anything techinal. A tune will hide the light for the emissions check.

In the big picture, your engine and turbo will act much differently now, due to restrictive air pressure against the turbo being gone. Your stock cat creates pressure that pushes against the impeller in the turbo and restricts it from spinning "freely". Due to this you should tune the engine to compensate for that. At a minimum your air to fuel ratio is going to change and you want your engine to run effiiciently.
__________________
F10 535i | Retired: E60 ///M5 | E92 335i

"If everything seems under control, you're not going fast enough"
-Mario Andretti
Appreciate 1
      03-20-2020, 01:27 PM   #9
Gjohnson7
Lieutenant
Gjohnson7's Avatar
254
Rep
422
Posts

Drives: 11' BMW 535i, 12' Lexus RX350,
Join Date: Aug 2019
Location: Broken Arrow, OK

iTrader: (3)

Garage List
2011 535i  [0.00]
So has anyone given this a shot? Would definitely like to hear some feedback.
Seems to be popular with the M5 and other N55 platforms. I may give this a shot myself.
__________________
Checkout my YouTube channel, Like and Subscribe. https://www.youtube.com/user/Gjohnson7771
MHD Flash, RVG Catless DP, RVG CP, RVG Boost Pipe, Walbro 455 LPFP, Style 433 Wheels, BC Coilovers, Ebay Strut bar, M-Sport Front Conversion, RVG FMIC, 6WB Cluster.
Appreciate 0
      03-20-2020, 02:25 PM   #10
Unspec
Colonel
Unspec's Avatar
1265
Rep
2,573
Posts

Drives: 2015 BMW 535xi
Join Date: Apr 2019
Location: DMV

iTrader: (1)

Not a particularly great idea imo. Catless DP aren't too expensive, the VRSF one is 350 bucks. The stock DP can sell easily for 400. Why not just sell the OEM one, buy the VRSF, and make 50 bucks?
__________________
2015 BMW 535xi
Bootmod3 Stage 2 | ER charge pipe | ER Catted DP | Remus Exhaust | Gplus FMIC | KW V3 | Turner Monoball thrust arm bushings | Wallet regrets
ISTA VM Setup/Tutorial
Appreciate 0
      03-20-2020, 03:16 PM   #11
Gjohnson7
Lieutenant
Gjohnson7's Avatar
254
Rep
422
Posts

Drives: 11' BMW 535i, 12' Lexus RX350,
Join Date: Aug 2019
Location: Broken Arrow, OK

iTrader: (3)

Garage List
2011 535i  [0.00]
Quote:
Originally Posted by Unspec View Post
Not a particularly great idea imo. Catless DP aren't too expensive, the VRSF one is 350 bucks. The stock DP can sell easily for 400. Why not just sell the OEM one, buy the VRSF, and make 50 bucks?
Hmm, well I have 132k miles on my stock cat anyway, No emission inspections in my state and I could gut for free and Flash MHD Stage 2. I've heard that the aftermarket DP's can have fitment issues.

Swapping for an Aftermarket Catless DP that could have fitment issues, sounds like more trouble. Making $50 bucks sounds cool, but probably wouldn't work out after shipping and price negotiations. Ultimately, I just need a pipe and O2 bungs, unless I'm really missing something. There really doesn't seem to be an advantage buying aftermarket catless DP. If I wanted to run a higher flowing Cat, I could see the aftermarket making more sense.
Appreciate 0
      03-20-2020, 06:53 PM   #12
5soko
Brigadier General
5soko's Avatar
332
Rep
4,632
Posts

Drives: M5
Join Date: Aug 2007
Location: Brooklyn, NY

iTrader: (4)

Been running my catless OEM downpipe for a few years now, on JB4 and MHD, logs perfectly, runs and sounds great...
The de-catted OEM DP, Fitment is perfect, mounts are perfect, and the flex joint is perfectly placed to not put stress on the turbo which alot of aftermarket DP's are missing, along with the mounts.

You can find my older threads with information and pics i have posted. The ease of install of the oem DP after you de-catted it, is a breeze! Not even the best aftermarket downpipe will fit as good and be such a easy install.
__________________
Current: E63S AMG 4matic RENNtech || M5 Evolve..Eventuri || F10 LCI 535i MHD

Last edited by 5soko; 03-21-2020 at 10:20 AM..
Appreciate 0
      03-20-2020, 07:19 PM   #13
Gjohnson7
Lieutenant
Gjohnson7's Avatar
254
Rep
422
Posts

Drives: 11' BMW 535i, 12' Lexus RX350,
Join Date: Aug 2019
Location: Broken Arrow, OK

iTrader: (3)

Garage List
2011 535i  [0.00]
Quote:
Originally Posted by 5soko View Post
Been running my catless OEM downpipe for a few years now, on JB4 and MHD, logs perfectly, runs and sounds great...
The de-catted OEM DP, Fitment is perfect, mounts are perfect, and the flex joint is perfectly placed to not put stress on the turbo.

You can find my older threads with information and pics i have posted. The ease of install of the oem DP after you de-catted it, is a breeze! Not even the best aftermarket downpipe will fit as good and be such a easy install.
That's great to hear. I will see if I can find your old threads.
__________________
Checkout my YouTube channel, Like and Subscribe. https://www.youtube.com/user/Gjohnson7771
MHD Flash, RVG Catless DP, RVG CP, RVG Boost Pipe, Walbro 455 LPFP, Style 433 Wheels, BC Coilovers, Ebay Strut bar, M-Sport Front Conversion, RVG FMIC, 6WB Cluster.
Appreciate 0
      04-01-2020, 09:48 PM   #14
Gjohnson7
Lieutenant
Gjohnson7's Avatar
254
Rep
422
Posts

Drives: 11' BMW 535i, 12' Lexus RX350,
Join Date: Aug 2019
Location: Broken Arrow, OK

iTrader: (3)

Garage List
2011 535i  [0.00]
Quote:
Originally Posted by 5soko View Post
Been running my catless OEM downpipe for a few years now, on JB4 and MHD, logs perfectly, runs and sounds great...
The de-catted OEM DP, Fitment is perfect, mounts are perfect, and the flex joint is perfectly placed to not put stress on the turbo which alot of aftermarket DP's are missing, along with the mounts.

You can find my older threads with information and pics i have posted. The ease of install of the oem DP after you de-catted it, is a breeze! Not even the best aftermarket downpipe will fit as good and be such a easy install.
Do you happen to have any videos of the sound? Looking for startup, idle and wot.
__________________
Checkout my YouTube channel, Like and Subscribe. https://www.youtube.com/user/Gjohnson7771
MHD Flash, RVG Catless DP, RVG CP, RVG Boost Pipe, Walbro 455 LPFP, Style 433 Wheels, BC Coilovers, Ebay Strut bar, M-Sport Front Conversion, RVG FMIC, 6WB Cluster.
Appreciate 0
      04-01-2020, 11:26 PM   #15
lsturbointeg
Lieutenant General
lsturbointeg's Avatar
United_States
9149
Rep
14,522
Posts

Drives: 2011 535i Jet Black
Join Date: Aug 2014
Location: Asian lost in OH

iTrader: (0)

Quote:
Originally Posted by Gjohnson7 View Post
Do you happen to have any videos of the sound? Looking for startup, idle and wot.
There's a video on Youtube with someone who did this. i'll see if i can find it.
__________________
~F90Conversion~21"3Piece Forged AvantGardeWheels~KWV1Coilovers~CQUENCE slotted/drilled rotors~GoodridgeStainlesslines~MeisterschaftQuadEx haust~Akrapovic 4"tips~VRSF DP~VRSF CP~TurboSmart BOV~K&N filter~CarbonFiberExteriorComponents~GladenAlphaCo mponents~MatchUp7BMW~Punch P300-12T~
Follow me on Instagram: lsturbointeg
Appreciate 0
      04-02-2020, 12:02 PM   #16
BimmerHausPerformance
Major
BimmerHausPerformance's Avatar
512
Rep
1,440
Posts

Drives: 2011 535i 6MT
Join Date: Apr 2019
Location: Chattanooga

iTrader: (1)

Garage List
2011 BMW 535i  [0.00]
Quote:
Originally Posted by Gjohnson7 View Post
Do you happen to have any videos of the sound? Looking for startup, idle and wot.
You could look at my youtube videos but I have full armytrix exhaust and mhd stage 2+.
__________________

2011 F10 S55 6MT
Website Insta @bimmerhausperformance YouTube
Appreciate 0
      04-02-2020, 07:28 PM   #17
5soko
Brigadier General
5soko's Avatar
332
Rep
4,632
Posts

Drives: M5
Join Date: Aug 2007
Location: Brooklyn, NY

iTrader: (4)

Quote:
Originally Posted by Gjohnson7 View Post
Do you happen to have any videos of the sound? Looking for startup, idle and wot.
Sounds like every other catless N55 to be honest, i will try to find a cold start.

It really surprising how quiet even with being catless these cars are, im running oem exhaust otherwise, no drone increased, but alot alot of turbo spool noises! otherwise cold start is louder but driving WOT minimal noise increase.
__________________
Current: E63S AMG 4matic RENNtech || M5 Evolve..Eventuri || F10 LCI 535i MHD
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 08:22 AM.




5post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST