E90Post
 


 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > NA Engine (non-turbo) / Drivetrain / Exhaust Modifications > AA Gen 2 Rear Exhaust (axle back exhaust) - Review



Reply
 
Thread Tools Search this Thread
      10-04-2018, 07:13 PM   #23
N52UNED
Captain
N52UNED's Avatar
United_States
181
Rep
601
Posts

Drives: '07 328i/330BPC
Join Date: Mar 2017
Location: Sunshine State

iTrader: (1)

Quote:
Originally Posted by atmosphericM View Post
Do what you will but I'll be very surprised if any "custom resonator" makes it any quieter than it is currently. Look at the inside of the OE center muffler, it's perforated and packed. I could be wrong... glad you'll be the guinea pig.

But what I'm really confused by is that you'd want to get rid of secondary cats, which will only make things louder, if you're already complaining about the noise levels?

I'm thinking that the torque converter is leading to more noise in those lower RPMs, but I'm clueless as to exactly how those automatic transmissions work. Either way, yeah, most MT guys are never below 2000 RPM. MT N52's are suuuper slow down there...
A custom resonator can be made to filter out certain frequencies, at certain RPMs; since they're basically an echo chamber that "tunes" the exhaust note and takes out drone not quiet the db levels ... that's the muffler's job.

With that it can be made to take out the very low register at low RPMs, and get the overall sound I'm looking for in combination with the AA Gen 2's tone.

As for deleting the secondary cats ... Granted cats do muffle the sound and change the tone a bit ... honestly I don't know how much the secondaries do compared to the main cat in effecting the overall tone. I've found videos of only secondary cat deletes, but some don't seem to change much while other do. Same thing with pops and crackles.
__________________
'07 328i auto ... 3IM - BPC Stage 1 - K&N / Carbon Delete - Turner Silicone Intake Tube - AA Gen 2 Exhaust
Appreciate 0
      10-04-2018, 07:59 PM   #24
FlaPatsFan
Major
749
Rep
1,149
Posts

Drives: 2011 328i wagon
Join Date: Apr 2017
Location: Florida

iTrader: (0)

Quote:
Originally Posted by N52UNED View Post
A custom resonator can be made to filter out certain frequencies, at certain RPMs; since they're basically an echo chamber that "tunes" the exhaust note and takes out drone not quiet the db levels ... that's the muffler's job.

With that it can be made to take out the very low register at low RPMs, and get the overall sound I'm looking for in combination with the AA Gen 2's tone.

As for deleting the secondary cats ... Granted cats do muffle the sound and change the tone a bit ... honestly I don't know how much the secondaries do compared to the main cat in effecting the overall tone. I've found videos of only secondary cat deletes, but some don't seem to change much while other do. Same thing with pops and crackles.
I loved the sound of my exhaust when I had the Gen2 axel back, custom resonator and secondary cat delete. I’m missing it right now as I’m still getting used to my AA catless headers. Loud!
Appreciate 1
N52UNED181.00
Reply

Bookmarks


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 02:34 AM.




e90post
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