BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Engine, Transmission, Exhaust, Drivetrain, ECU Software Modifications
 
GetBMWParts
Post Reply
 
Thread Tools Search this Thread
      03-13-2012, 12:59 AM   #1
raywong
Private First Class
 
Drives: E92M3
Join Date: Jun 2011
Location: Hong Kong

Posts: 132
iTrader: (0)

secondary cat delete

has anyone removed the secondary cats? I wanted to do it but the muffler guy is warning me about the 2000rpm drone. I really don't want any drone just want higher pitch. Any advice please?
raywong is offline   No_Country
0
Reply With Quote
      03-13-2012, 01:11 AM   #2
FVM3
Major General
 
FVM3's Avatar
 
Drives: e92 m3, f30 328i
Join Date: Sep 2010
Location: Los Angeles

Posts: 5,711
iTrader: (2)

as soon as you have the stock muffler, no drone but sounds really raspy
FVM3 is offline  
0
Reply With Quote
      03-13-2012, 02:23 AM   #3
raywong
Private First Class
 
Drives: E92M3
Join Date: Jun 2011
Location: Hong Kong

Posts: 132
iTrader: (0)

Hey man what's up?
I just installed innotech valvetronic exhaust on my 360, so much drone I get a headache all the time. This is why I started using my M3 more now. Anything else I need to know about cats removal?
Thanks
raywong is offline   No_Country
0
Reply With Quote
      03-13-2012, 02:48 AM   #4
FVM3
Major General
 
FVM3's Avatar
 
Drives: e92 m3, f30 328i
Join Date: Sep 2010
Location: Los Angeles

Posts: 5,711
iTrader: (2)

it will say incresed emission but theres some way to get rid of that. If you get the innotech , you may get drone after deleting resonator but not cats.
FVM3 is offline  
0
Reply With Quote
      03-13-2012, 03:57 AM   #5
saeedg48
Brigadier General
 
Drives: 12 CLS63 + 14 M6 C
Join Date: Nov 2008
Location: Unknown

Posts: 3,499
iTrader: (1)

i had a catless xpipe. i wouldn't recommend it. they're no power gains. i'd consider a primary catdelete. it sounds much better. nice growl, and with my stock mufflers i didn't get any drone, despite what some claim on the forums. so do a primary catdelete (turner test pipe ~$300). once you CEL turns on ignore it, tune it, or purchase the akro cel delete.

more power, more noise.
__________________


2008 M3 Sedan + TestPipes + Tune [sold]

2012 CLS63 AMG + P30 Performance Package
2014 M6 Coupe + AMS Downpipes + KW V3
saeedg48 is offline   Iran
0
Reply With Quote
      03-13-2012, 04:07 AM   #6
FVM3
Major General
 
FVM3's Avatar
 
Drives: e92 m3, f30 328i
Join Date: Sep 2010
Location: Los Angeles

Posts: 5,711
iTrader: (2)

Quote:
Originally Posted by saeedg48 View Post
i had a catless xpipe. i wouldn't recommend it. they're no power gains. i'd consider a primary catdelete. it sounds much better. nice growl, and with my stock mufflers i didn't get any drone, despite what some claim on the forums. so do a primary catdelete (turner test pipe ~$300). once you CEL turns on ignore it, tune it, or purchase the akro cel delete.

more power, more noise.
x pipe should gain some hp but not much
FVM3 is offline  
0
Reply With Quote
      03-13-2012, 05:49 AM   #7
raywong
Private First Class
 
Drives: E92M3
Join Date: Jun 2011
Location: Hong Kong

Posts: 132
iTrader: (0)

I heard the primary cats are 400cell and secondary are 200cell What if I replace the primary cats with straight pipe and move the sensors to the secondary cats. This way I get free flowing system without cel.
raywong is offline   No_Country
0
Reply With Quote
      03-13-2012, 07:02 AM   #8
M3SQRD
Colonel
 
M3SQRD's Avatar
 
Drives: E92 M3s, R56 Cooper S
Join Date: Jun 2009
Location: EC

Posts: 2,453
iTrader: (2)

Quote:
Originally Posted by raywong View Post
I heard the primary cats are 400cell and secondary are 200cell What if I replace the primary cats with straight pipe and move the sensors to the secondary cats. This way I get free flowing system without cel.
You'll still get a CEL because the O2 sensors are located before and after the primary cats. Relocating the primary cats is basically the same as removing them - the rear O2 sensors will have the same readings/measurements as the front O2 sensors so the DME will detect a cat inefficiency issue.
M3SQRD is offline   United_States
0
Reply With Quote
      03-13-2012, 08:54 AM   #9
Templar
Lieutenant Colonel
 
Templar's Avatar
 
Drives: 2011 E92 M3
Join Date: Feb 2009
Location: One of the coasts...

Posts: 1,816
iTrader: (1)

Garage List
2011 BMW M3  [5.00]
Quote:
Originally Posted by saeedg48 View Post
i had a catless xpipe. i wouldn't recommend it. they're no power gains. i'd consider a primary catdelete. it sounds much better. nice growl, and with my stock mufflers i didn't get any drone, despite what some claim on the forums. so do a primary catdelete (turner test pipe ~$300). once you CEL turns on ignore it, tune it, or purchase the akro cel delete.

more power, more noise.
Hmm, I'm pretty sure a catless setup is the (if not one of the) best and most cost effective ways to get more power...
__________________
'11 BMW E92 ///M3 - ZCP and DCT
'13 Toyota Tundra - 4x4 Platinum CrewMax, 5.7l iForce V8
Templar is offline   United_States
0
Reply With Quote
      03-13-2012, 12:16 PM   #10
M3PO
Colonel
 
M3PO's Avatar
 
Drives: '08 IB E92
Join Date: Sep 2011
Location: OC

Posts: 2,729
iTrader: (6)

Quote:
Originally Posted by raywong View Post
I heard the primary cats are 400cell and secondary are 200cell What if I replace the primary cats with straight pipe and move the sensors to the secondary cats. This way I get free flowing system without cel.
You may still get a CEL from time to time if you do this. It would be similar to the Fabspeed x-pipe. People occasionally get a CEL but it will go away.

I have an OEM x-pipe with a secondary cat delete only and it isn't much different than stock honestly. Removing the secondary cat is only good for a few horsepower also since the catalyst pitch is so large.
M3PO is offline  
0
Reply With Quote
      03-13-2012, 12:30 PM   #11
flipm3
E46 + E90
 
Drives: E46 M3 + E90 M3
Join Date: Jul 2008
Location: Illinois

Posts: 2,772
iTrader: (1)

Garage List
2009 BMW M3  [0.00]
2002 BMW M3  [0.00]
Depending on how much you want to spend, I'd do the following:

Primary Cat Delete (Turner Test Pipes or any other cat'd mid pipe)
Evolve Automotive Stage 2 Tune

The Evolve tune will not only add power, but it will remove the CEL while keeping your post-cat O2 sensors in ready state for off-road use.
__________________
E90 M3 DCT|Melbourne Red . Speed Cloth | My Build Thread
E46 M3 6MT|Jet Black . Black Nappa Leather | My Build Thread
flipm3 is offline   Philippines
0
Reply With Quote
      03-13-2012, 12:37 PM   #12
1MOREMOD
2014 Track Days - 10|Ridge 1:52:24|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 12,206
iTrader: (5)

lot less to gain from secondary cat delete than the primaries and will add drone like going fully catless. as above i am stage 2 with evolve and love it.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW exhaust|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      03-13-2012, 01:01 PM   #13
DemonEye
Private First Class
 
DemonEye's Avatar
 
Drives: 2012 M3 Coupe ESS VT2-625
Join Date: Jul 2011
Location: Charlotte, NC

Posts: 109
iTrader: (0)

Garage List
2010 135i Coupe  [0.00]
2012 M3 Coupe  [0.00]
I had my OEM xpipe gutted, both primary and secondary cats are gone. Sound is pretty "mean" when wide open, sounds stock when light on the throttle. Not hearing this drone that people are talking about. Still have stock resonators and stock exhaust in place though. Smell is pretty bad. I have the AA tune so no CEL for me.
DemonEye is offline   United_States
0
Reply With Quote
      03-22-2012, 01:31 PM   #14
abramelkyzedeck
Private First Class
 
Drives: bmw m3
Join Date: Sep 2011
Location: san francisco

Posts: 109
iTrader: (0)

i just removed my primary cats and as usual the cel was on. I was wondering if the cel will turn off if i installed back the primary cats
abramelkyzedeck is offline  
0
Reply With Quote
      03-22-2012, 02:05 PM   #15
Rekrul
Captain
 
Rekrul's Avatar
 
Drives: Space Gray e92 M3
Join Date: Aug 2011
Location: Purgatory

Posts: 790
iTrader: (1)

Quote:
Originally Posted by abramelkyzedeck View Post
i just removed my primary cats and as usual the cel was on. I was wondering if the cel will turn off if i installed back the primary cats
Yes it would. Though you may need to clear the code once you reinstall your primary.


I have the DINAN catless x pipe.. and it sounds fuckin amazing. No Drone. But I have the Akra slip on too.
Rekrul is offline  
0
Reply With Quote
      03-22-2012, 02:08 PM   #16
aus
Major General
 
Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

Posts: 7,323
iTrader: (5)

Quote:
Originally Posted by raywong View Post
I heard the primary cats are 400cell and secondary are 200cell What if I replace the primary cats with straight pipe and move the sensors to the secondary cats. This way I get free flowing system without cel.
It's not easy to extend the O2 sensors. You need to have cables that are almost exactly the same density as the stock ones. It has to do with conductance of the cable in combination with the actual O2 sensor.
I would love to get rid of the primary cats, and have a 200 or 300cpi cat in the secondary cat location and move the O2 sensor back to after the cats in the secondary position. No tune necessary, no check engine light and less smell than the Akra X-pipe.

.
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
aus is offline  
0
Reply With Quote
      03-23-2012, 05:46 AM   #17
blackbeast535
Private First Class
 
blackbeast535's Avatar
 
Drives: 2008 M3 6MT Jerez Black
Join Date: Aug 2011
Location: MD

Posts: 144
iTrader: (0)

I have removed the secondaries and running Dinan rear mufflers no drone here. Sounds exotic above 3k rpm. Definitely a head turner. Do a search and find my review.
__________________


E90 M3 Jerez Black/Bamboo Beige 6MT - BMW CCA
Dinan Rear Exhaust, Secondary Cat Delete, Dinan High Flow Carbon Fiber Intake, IND Painted Reflectors, BMW Edition Grills
blackbeast535 is offline   United_States
0
Reply With Quote
      03-24-2012, 04:36 PM   #18
Serpico
Captain
 
Drives: M3
Join Date: Mar 2012
Location: MD-NY

Posts: 617
iTrader: (1)

How much HP is gained from secondary cat removal?
Serpico is offline  
0
Reply With Quote
      03-24-2012, 06:06 PM   #19
In Extremis
Jordan C
 
In Extremis's Avatar
 
Drives: 09 MR E92 M3, 65 GTO
Join Date: Aug 2010
Location: Long Island, NY

Posts: 371
iTrader: (1)

Quote:
Originally Posted by Rekrul View Post
Yes it would. Though you may need to clear the code once you reinstall your primary.


I have the DINAN catless x pipe.. and it sounds fuckin amazing. No Drone. But I have the Akra slip on too.
Nice combo^^^

I'm going to start running my catless xpipe this week with the stock axle back. It's a non-resonated gintani, should be interesting. I wouldn't bother with the secondary cats unless you do the primaries too. Keeping the stock xpipe is up to you.
__________________
Melbourne Red E92 M3 DCT Sparco CF/Alcantara DTM Seats.KW3 Coilovers.Apex Wheels.OEM Performance Spoiler with CRT Theme & Splitters.Turner Subframe Mounts.Vorshlag Camber Plates.RD Sway Bars.AD08s 265/295.15 lb. Braille Battery.Catless Gintani Race.ESS Tune.Dinan Pulley.MS2 Intake.100 Octane Mix.Schroth Harnesses.Challenge Harness Bar in MR.Challenge Toe Link.Krics R40.Turner Studs/Pedals.SS Lines.Rear Seat Delete & more I can't remember
In Extremis is offline   United_States
0
Reply With Quote
      03-27-2012, 07:24 AM   #20
e92Mjunky
Second Lieutenant
 
Drives: New wife Alpine CF E92 M3
Join Date: Mar 2011
Location: Austin, TX

Posts: 272
iTrader: (0)

wonder if it would be worth removing the secondary cats and welding them in where the primary's are...that way you still have cats, just more flowing and you get rid of the more restrictive primarys
__________________

08' DCT CF Roof, nothing to fancy
custom magnaflow exhaust amd drop in filter
e92Mjunky is offline   United_States
0
Reply With Quote
      03-27-2012, 08:50 AM   #21
1MOREMOD
2014 Track Days - 10|Ridge 1:52:24|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 12,206
iTrader: (5)

Quote:
Originally Posted by e92Mjunky View Post
wonder if it would be worth removing the secondary cats and welding them in where the primary's are...that way you still have cats, just more flowing and you get rid of the more restrictive primarys
the original cats are also smashed flat as is the piping in that area. going to hfc also removes these areas of restriction in the flow.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW exhaust|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      03-27-2012, 01:23 PM   #22
e92Mjunky
Second Lieutenant
 
Drives: New wife Alpine CF E92 M3
Join Date: Mar 2011
Location: Austin, TX

Posts: 272
iTrader: (0)

yeah i noticed that on mine, looked like the secondarys were a smaller diameter, but you are probably correct...
__________________

08' DCT CF Roof, nothing to fancy
custom magnaflow exhaust amd drop in filter
e92Mjunky is offline   United_States
0
Reply With Quote
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
Forum Jump


All times are GMT -5. The time now is 09:06 AM.




m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
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