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
 
BPM Sport
Post Reply
 
Thread Tools Search this Thread
      08-28-2009, 01:03 AM   #1
aus
Major General
 
Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

Posts: 7,323
iTrader: (5)

Question on modifying the stock mid-section.

In this pic (thanks EAS), it looks like the secondary cats are held to the primary cats by band clamps? Is that the case?

Also, does the bracket at the X-pipe support the exhaust there?

Just wondering if one could have a shop to just cut out the secondary cats and X-pipe and replace it with an X-pipe and some piping while keeping the resonators?

__________________
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
      08-31-2009, 10:31 PM   #2
aus
Major General
 
Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

Posts: 7,323
iTrader: (5)

Someone must know if the mid-section is all one piece?
__________________
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
      08-31-2009, 10:51 PM   #3
Edman951
Second Lieutenant
 
Edman951's Avatar
 
Drives: F10 550xi, Alpine white
Join Date: Nov 2006
Location: Montreal, Quebec

Posts: 285
iTrader: (1)

Yes, the mid-section is one piece
those clamps and support are to hold the pipes to brackets on the car.

You could cut it up and get a shop to make you a custome setup.
A few here have done it
Edman951 is offline   Canada
0
Reply With Quote
      09-01-2009, 04:58 AM   #4
simonlam168
Second Lieutenant
 
simonlam168's Avatar
 
Drives: E93-M3 F10-M5
Join Date: Apr 2009
Location: Hong Kong

Posts: 253
iTrader: (1)

I have done second cats delete x pipe combined with 4 resonators yesterday. I add 2 x 14" magnaflow resonator to slightly cut the loudness and get rid of the drone.

simonlam168 is offline   Hong Kong
0
Reply With Quote
      09-01-2009, 05:53 AM   #5
mixja
Captain
 
Drives: 2011 E90 DCT Silverstone
Join Date: Jun 2008
Location: Beverly Hils, CA

Posts: 783
iTrader: (1)

Quote:
Originally Posted by simonlam168 View Post
I have done second cats delete x pipe combined with 4 resonators yesterday. I add 2 x 14" magnaflow resonator to slightly cut the loudness and get rid of the drone.
So how close to stock does this sound? Is the OEM Primary Cat restrictive in its flow?
mixja is offline   United_States
0
Reply With Quote
      09-01-2009, 07:10 AM   #6
MrHarris
yodog
 
MrHarris's Avatar
 
Drives: '86 Corolla
Join Date: Jun 2007
Location: Diamond Bar, Ca

Posts: 5,038
iTrader: (5)

Garage List
2009 BMW  [5.00]
Send a message via AIM to MrHarris
How much did the magnaflow resonators cost? How you like them?
__________________

2009 E92 M3 | Alpine White | Black Extended | Advan RS | Turner Test Pipes | Dinan Axle-Back | OETuning | Eibach Springs | UUC SSK | VRS Front Lip | VRS Type I Diffuser | Matte Black | RPi Scoops | MS Filter | Yokohama AD08 | F1 Pinnacle
Special Thanks: Gintani | OETuning | eAs
MrHarris is offline   United_States
0
Reply With Quote
      09-01-2009, 07:28 AM   #7
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

http://www.m3post.com/forums/showthr...ary+cat+delete
__________________
J08M3 is offline   United_States
0
Reply With Quote
      09-01-2009, 08:17 AM   #8
simonlam168
Second Lieutenant
 
simonlam168's Avatar
 
Drives: E93-M3 F10-M5
Join Date: Apr 2009
Location: Hong Kong

Posts: 253
iTrader: (1)

I have Meisterchaft GT2 exhaust with SR pipe installed. It's too loud for normal drive. It sounds almost like Ferrari but louder and the drone is crazy. The drone is annoying me when going uphill. It's much better after 2 additional magnaflow resonators installed. Drone from 2-3krpm is eliminated or at least highly reduced from what it was before.
simonlam168 is offline   Hong Kong
0
Reply With Quote
      09-01-2009, 08:26 AM   #9
simonlam168
Second Lieutenant
 
simonlam168's Avatar
 
Drives: E93-M3 F10-M5
Join Date: Apr 2009
Location: Hong Kong

Posts: 253
iTrader: (1)

Quote:
Originally Posted by mixja View Post
So how close to stock does this sound? Is the OEM Primary Cat restrictive in its flow?
I think the sound is more quiet. The resonator is less restrictive than the OEM seoncd cats.

Two magnaflow resonators cost USD130. Parts number 14419.
simonlam168 is offline   Hong Kong
0
Reply With Quote
      09-01-2009, 04:58 PM   #10
aus
Major General
 
Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

Posts: 7,323
iTrader: (5)

Quote:
Originally Posted by J08M3 View Post
Missed that one. Four pages and NO DYNO's to see if there's any power gain?
__________________
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."

Last edited by aus; 09-01-2009 at 05:48 PM.
aus is offline  
0
Reply With Quote
      09-01-2009, 07:53 PM   #11
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

Quote:
Originally Posted by aus View Post
Missed that one. Four pages and NO DYNO's to see if there's any power gain?
There's definitely power gain if you look at the pic of the inside of the secondary cat and see the restriction.... The question is how much??? To be honest, the car seemed to pull good and strong when I did this and at the time is was combined with an Eisenmann Sport. But measurable power increase was probably minimal. Sound was greatly improved. The main restriction in our systems is the primary cat though. That's the key to increasing power, doing something about the OEM primary.
__________________
J08M3 is offline   United_States
0
Reply With Quote
      09-01-2009, 08:19 PM   #12
mixja
Captain
 
Drives: 2011 E90 DCT Silverstone
Join Date: Jun 2008
Location: Beverly Hils, CA

Posts: 783
iTrader: (1)

Quote:
Originally Posted by J08M3 View Post
There's definitely power gain if you look at the pic of the inside of the secondary cat and see the restriction.... The question is how much??? To be honest, the car seemed to pull good and strong when I did this and at the time is was combined with an Eisenmann Sport. But measurable power increase was probably minimal. Sound was greatly improved. The main restriction in our systems is the primary cat though. That's the key to increasing power, doing something about the OEM primary.
I wonder what the sound would be like with ONLY the primary cat delete....

Most people won't do this because you'll throw a CEL but in my case that is taken care of with Powerchip Stage II...

Hesitant to chop up the factory system - but I guess you could always weld the primary cat back on if it didn't work out....

The other aspect of this I'm interested in is whether the infamous torque dip around 2500RPM would be present with just primary cat delete? I.e. would the remainder of the stock system still have enough backpressure to mitigate the torque dip?
mixja is offline   United_States
0
Reply With Quote
      09-02-2009, 04:31 AM   #13
mixja
Captain
 
Drives: 2011 E90 DCT Silverstone
Join Date: Jun 2008
Location: Beverly Hils, CA

Posts: 783
iTrader: (1)

Quote:
Originally Posted by mixja View Post
I wonder what the sound would be like with ONLY the primary cat delete....

Most people won't do this because you'll throw a CEL but in my case that is taken care of with Powerchip Stage II...

Hesitant to chop up the factory system - but I guess you could always weld the primary cat back on if it didn't work out....

The other aspect of this I'm interested in is whether the infamous torque dip around 2500RPM would be present with just primary cat delete? I.e. would the remainder of the stock system still have enough backpressure to mitigate the torque dip?
Just saw these from Turner (http://www.turnermotorsport.com/html..._ID=TEN9046MTP) - I guess these would be ideal to do the primary cat delete - anybody got these installed?

mixja is offline   United_States
0
Reply With Quote
      09-02-2009, 11:42 AM   #14
NavM3
M-Sport
 
NavM3's Avatar
 
Drives: 2011 GT-R
Join Date: Oct 2007
Location: DC area

Posts: 172
iTrader: (0)

Quote:
Originally Posted by mixja View Post
Just saw these from Turner (http://www.turnermotorsport.com/html..._ID=TEN9046MTP) - I guess these would be ideal to do the primary cat delete - anybody got these installed?



Based on what I read, the power gains with 2ndary cat delete are minimal so the turner set up is an option since you are willing to cut the midpipe and weld it to the turner straight pipe. The better option is to go with High flow sport cats from Fabspped or Encore and weld it to the rest of the x-pipe. That way, you gain the most since the primary cats are the most restrictive part of the exhaust and keep the stock secondary cats and resonator to keep the noise levels down and won't be smelling or inhaling exhaust fumes.



Another option, albeit more noisy, would be to get the high flow cats along with the resonated x-pipe. It will be noisier due to lack of secondary cats but I don't know how loud it is going to be. The advantage would be a little more power and no cutting of the stock midpipe.
Attached Images
  
NavM3 is offline  
0
Reply With Quote
      09-02-2009, 04:26 PM   #15
mixja
Captain
 
Drives: 2011 E90 DCT Silverstone
Join Date: Jun 2008
Location: Beverly Hils, CA

Posts: 783
iTrader: (1)

Quote:
Originally Posted by NavM3 View Post
Based on what I read, the power gains with 2ndary cat delete are minimal so the turner set up is an option since you are willing to cut the midpipe and weld it to the turner straight pipe. The better option is to go with High flow sport cats from Fabspped or Encore and weld it to the rest of the x-pipe. That way, you gain the most since the primary cats are the most restrictive part of the exhaust and keep the stock secondary cats and resonator to keep the noise levels down and won't be smelling or inhaling exhaust fumes.
With the Primary Cat delete, you still have the Secondary Cats in place, so I'm assuming fumes won't be an issue (also where I live we don't have emissions checks so that isn't an issue for me). So I don't really see the point of replacing the primary cats with high flow cats in my situation, if you are going to keep the secondary cats.

The only potential reason for replacing with high flow primary cats would be that having a straight through pipe might upset your backpressure balance too much causing the low RPM torque dip you see with full aftermarket systems - but I'm picking the remainder of the OEM system will keep a sufficient amount of backpressure to avoid this issue (and hopefully still be able to flow enough to maximise power at high RPMs)


Quote:
Originally Posted by NavM3 View Post
Another option, albeit more noisy, would be to get the high flow cats along with the resonated x-pipe. It will be noisier due to lack of secondary cats but I don't know how loud it is going to be. The advantage would be a little more power and no cutting of the stock midpipe.
Not really an option for me, want as close to stock as possible (just want performance gains )
mixja is offline   United_States
0
Reply With Quote
      09-02-2009, 08:27 PM   #16
mixja
Captain
 
Drives: 2011 E90 DCT Silverstone
Join Date: Jun 2008
Location: Beverly Hils, CA

Posts: 783
iTrader: (1)

Quote:
Originally Posted by NavM3 View Post
Based on what I read, the power gains with 2ndary cat delete are minimal so the turner set up is an option since you are willing to cut the midpipe and weld it to the turner straight pipe. The better option is to go with High flow sport cats from Fabspped or Encore and weld it to the rest of the x-pipe. That way, you gain the most since the primary cats are the most restrictive part of the exhaust and keep the stock secondary cats and resonator to keep the noise levels down and won't be smelling or inhaling exhaust fumes.
My reading of the product is you only cut - you don't need to weld because it provides clamps that seal the system.
mixja 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 03:22 PM.




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