Replacing Secondary Cats with Eisenmann Straight Pipes (w/E-Sport Exhaust) - BMW M5 Forum and M6 Forums
E60 M5 and E61 M5 Touring Discussion 2005- Advertiser's Forum

 
LinkBack Thread Tools Rate Thread Display Modes
post #1 of 6 Old 13th June 2007, 10:15 PM Thread Starter
polar993
Addicted Member (>300 posts)
 
Join Date: Feb 2007
Location: Greenwich, CT
Posts: 360
Thanks: 0
Thanked 11 Times in 11 Posts
Replacing Secondary Cats with Eisenmann Straight Pipes (w/E-Sport Exhaust)

I recently swapped my Eisenmann Sport exhaust with an Eisenmann Race exhaust, but the sound is a bit too much for me (mainly on cold starts because I live in a condo with shared underground parking....I'm sensing that my neighbors are starting to dislike me because the car is so loud when I start it and leave the garage!).

I'm thinking about putting my E-Sport back on and replacing the secondary cats with the Eisenmann Section 1 straight pipes. For now, I would leave the stock resonators (Section 2) in place. From what I understand, replacing Section 1 will provide more sound than replacing Section 2. Hopefully this will give me the perfect sound that I'm looking to achieve, and won't be too loud on a cold start.

Has anyone replaced Section 1 and kept the stock Section 2, with or without an aftermarket exhaust? If so, I would really appreciate your feedback.

I am concerned about losing back-pressure if I remove the secondary cats and replace them with straight pipes (I've heard this is what happens). Can someone please explain the disadvantage of losing back-pressure? What exactly does that mean? Will I actually lose power as well?

Theoretically, if I create a less restrictive path for the exhaust system by removing the cats and replacing them with straight sections of pipe, that should create more free-flow and power, right?

Before I go down this path, I just want to make sure I'm doing the right thing.

I know the more common solution to adding more sound to an exhaust system is adding an x-pipe in place of the resonators, but again, I heard the sound increase from doing that is minimal.

I welcome and would appreciate your input.

Thanks!

Below are the videos of both my E-Sport & E-Race exhausts.....just looking for something in between.

E-Sport
http://www.youtube.com/watch?v=ROXwGcv0M5s

E-Race
http://www.youtube.com/watch?v=24gcF6bMFgI
polar993 is offline  
Sponsored Links
Advertisement
 
post #2 of 6 Old 13th June 2007, 11:06 PM
deknight
m5board.comoholic (>1000 posts)
 
deknight's Avatar
 
Join Date: Nov 2005
Location: Los Angeles, CA
Posts: 1,277
Thanks: 72
Thanked 35 Times in 30 Posts
[quote=polar993;1066885]...I'm thinking about putting my E-Sport back on and replacing the secondary cats with the Eisenmann Section 1 straight pipes. For now, I would leave the stock resonators (Section 2) in place. From what I understand, replacing Section 1 will provide more sound than replacing Section 2. Hopefully this will give me the perfect sound that I'm looking to achieve, and won't be too loud on a cold start.

Has anyone replaced Section 1 and kept the stock Section 2, with or without an aftermarket exhaust? If so, I would really appreciate your feedback.

I am concerned about losing back-pressure if I remove the secondary cats and replace them with straight pipes (I've heard this is what happens). Can someone please explain the disadvantage of losing back-pressure? What exactly does that mean? Will I actually lose power as well?

Theoretically, if I create a less restrictive path for the exhaust system by removing the cats and replacing them with straight sections of pipe, that should create more free-flow and power, right?...I know the more common solution to adding more sound to an exhaust system is adding an x-pipe in place of the resonators, but again, I heard the sound increase from doing that is minimal./quote]

Replacing the secondary cats will not give you that much of a sound increase, but it will increase the power yielding better flow. Sure it decreases the backpressure but not too much so. I have replaced on my M6 my 2ndary cats with straight pipe and the sound diff was small to none.

I have also replaced resonators (section 2) on my E39 M5 and it made a huge in sound way better. I had Dinan exhaust on and wanted it louder so adding the SS X-pipe really increased it. If you saw what the resonator looked like you would understand why it decreases sound so much. Even the name speaks to sound restriction. That is my experience anyway.

Here is a video I did comparing before and afters the cat delete. However, the before vid is my wife driving and she did not rev the engine that much or that high. I drove the after delete and revved much higher. Also the exhaust was broken in more for the cat delete. Listen to the sound at startup is the best compare on this vid.

http://www.youtube.com/watch?v=Zv3L5qR0NoI

deknight

2007 Nurburgring Blue M6 Full Black Int, carbon fiber, HUD, Ipod inter., charcoal filters out, BMC filters,
Comfort Access, Eisenmann Race exhaust, Evosport 3.91 2 clutch LSD, Vorsteiner Carbon Fiber hood,
HRE 545r 20" wheels, Evosport Pulley, Hartge springs, 20 mm HR frnt spacrs
Dinan Front Roll control, Dinan rear sway, Dinan Camber 650i Camber plate, Evosport Headers.and Section 1 high flow cats,
RPI Ram Air, Evosport Stage 2 S/W, AC Schnitzer rear wing & front splitters, Hamann apron.
2007 Alpine White Z4 M Coupe, Supersprint Sport Exhaust, X-pipe and Section 1,
Ground Control Coil Over, APR GTC 200 Rear Wing & Front Canards.
2002 blue water M5- Gone but not forgotten!!
Dinan Exhaust, Dinan Flywheel, Dinan Stage 2 software
Supersprint x-pipe, AA CAI, short shift kit , Dinan Stage 3 Koni suspension.

Last edited by deknight; 13th June 2007 at 11:11 PM.
deknight is offline  
post #3 of 6 Old 14th June 2007, 12:48 AM Thread Starter
polar993
Addicted Member (>300 posts)
 
Join Date: Feb 2007
Location: Greenwich, CT
Posts: 360
Thanks: 0
Thanked 11 Times in 11 Posts
Quote:
Originally Posted by deknight View Post
Replacing the secondary cats will not give you that much of a sound increase, but it will increase the power yielding better flow. Sure it decreases the backpressure but not too much so. I have replaced on my M6 my 2ndary cats with straight pipe and the sound diff was small to none.

I have also replaced resonators (section 2) on my E39 M5 and it made a huge in sound way better. I had Dinan exhaust on and wanted it louder so adding the SS X-pipe really increased it. If you saw what the resonator looked like you would understand why it decreases sound so much. Even the name speaks to sound restriction. That is my experience anyway.

Here is a video I did comparing before and afters the cat delete. However, the before vid is my wife driving and she did not rev the engine that much or that high. I drove the after delete and revved much higher. Also the exhaust was broken in more for the cat delete. Listen to the sound at startup is the best compare on this vid.

http://www.youtube.com/watch?v=Zv3L5qR0NoI
deknight, your M6 sounds great! In addition to the straight pipes, do you ALSO have the Eisenmann x-pipe with your Race exhaust? I realize what you mean by only a marginal difference with and without the straight-pipes/secondary cats, but I do hear the difference.

From what I've read on this board, adding the x-pipe to the E-Race makes a pretty big difference, but adding the x-pipe to the E-Sport will probably not make too much of a difference. The E-Sport is only a little bit louder than the stock mufflers.

BTW - I also like the difference in driving style between you and your wife! Very easy to tell who's got the heavy foot in the family!
polar993 is offline  
post #4 of 6 Old 14th June 2007, 01:36 AM
905RMP32V1x
Member, P500 Sport, DSC off (>900)
 
905RMP32V1x's Avatar
 
Join Date: Jun 2006
Location: Colleyville, TX
Posts: 930
Thanks: 0
Thanked 0 Times in 0 Posts
As far as power gained and lost...From what I've learned on this board you will not have a problem adding an X-pipe and straight through pipes. In fact deleting the primary cats and replacing the secondary cats with high flow race cats will give you a sizable increase.

2006 Indy Red/Blk/Alum loaded,
H&R springs w spacers, 167(M6) wheels,
Dinan 3.91, Evo Pulley
CF grills, CF vents, ACS Spoiler
Vorsteiner CF Vented Hood, CF lower steering wheel
905R-driver
MP32-irons
ProV1x-ball
905RMP32V1x is offline  
post #5 of 6 Old 14th June 2007, 04:28 AM
deknight
m5board.comoholic (>1000 posts)
 
deknight's Avatar
 
Join Date: Nov 2005
Location: Los Angeles, CA
Posts: 1,277
Thanks: 72
Thanked 35 Times in 30 Posts
Quote:
Originally Posted by polar993 View Post
deknight, your M6 sounds great! In addition to the straight pipes, do you ALSO have the Eisenmann x-pipe with your Race exhaust? I realize what you mean by only a marginal difference with and without the straight-pipes/secondary cats, but I do hear the difference.

From what I've read on this board, adding the x-pipe to the E-Race makes a pretty big difference, but adding the x-pipe to the E-Sport will probably not make too much of a difference. The E-Sport is only a little bit louder than the stock mufflers.

BTW - I also like the difference in driving style between you and your wife! Very easy to tell who's got the heavy foot in the family!
No I do not have the x-pipe on the M6. Thanks for the props though.

deknight

2007 Nurburgring Blue M6 Full Black Int, carbon fiber, HUD, Ipod inter., charcoal filters out, BMC filters,
Comfort Access, Eisenmann Race exhaust, Evosport 3.91 2 clutch LSD, Vorsteiner Carbon Fiber hood,
HRE 545r 20" wheels, Evosport Pulley, Hartge springs, 20 mm HR frnt spacrs
Dinan Front Roll control, Dinan rear sway, Dinan Camber 650i Camber plate, Evosport Headers.and Section 1 high flow cats,
RPI Ram Air, Evosport Stage 2 S/W, AC Schnitzer rear wing & front splitters, Hamann apron.
2007 Alpine White Z4 M Coupe, Supersprint Sport Exhaust, X-pipe and Section 1,
Ground Control Coil Over, APR GTC 200 Rear Wing & Front Canards.
2002 blue water M5- Gone but not forgotten!!
Dinan Exhaust, Dinan Flywheel, Dinan Stage 2 software
Supersprint x-pipe, AA CAI, short shift kit , Dinan Stage 3 Koni suspension.
deknight is offline  
post #6 of 6 Old 14th June 2007, 09:57 PM
Noah1
Member, Sport: Off DSC: On (>50 posts)
 
Noah1's Avatar
 
Join Date: Oct 2006
Location: Ramstein Germany
Posts: 51
Thanks: 5
Thanked 2 Times in 1 Post
Thumbs down Awesome Sound

Deknight, love the sound of your M6 can only hope my M sounds as good as yours when I receive my e-race in a couple of weeks, cant wait. -Noah
Noah1 is offline  
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the BMW M5 Forum and M6 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Similar Threads
Thread Thread Starter Forum Replies Last Post
Feedback on straight pipes? nathanielbrown E39 M5 and E52 Z8 Discussion 20 24th May 2007 11:51 PM
Installed Full Eisenmann Meisterschaft Exhaust Tonight! AMG ETR E60 M5 and E61 M5 Touring Discussion 34 20th January 2007 07:56 PM
Concern: Supersprint Headers Coupled w/ Removal of Secondary Cats KeithTa E63 BMW M6 Forum and BMW M6 Convertible | m6board.com 2 21st June 2006 07:24 PM
Group buy yet on Tubi???? Stevus M5 E39 Group Buy Forum and Sponsor Discussion and Offerings 381 14th December 2004 11:09 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome