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
 
INDustry distribution
Post Reply
 
Thread Tools Search this Thread
      08-09-2011, 02:02 AM   #1
avex8
Captain
 
avex8's Avatar
 
Drives: 11 E92 M3, 13 X3 35i, 14 650i
Join Date: May 2011
Location: San Diego

Posts: 731
iTrader: (2)

Help: how to reduce drone with my exhaust (RPI GTM)

Hey guys, i am currently running RPI GTM full system. I love the sound and the power but I HATE the in cabin drone/resonate especially that deep bassy drone, makes my ear almost go deaf. The drone only occur between 2K~3K rpm and there is little drone on the highway.

So now i am thinking about keeping the rpi axle back muffler, switch back to OEM x-pipe, and get turner test pipe (primary cat deleted to gain power). Anyone have this set up? how is the sound and drone noise? would this help reduce the drone and in cabin resonate?

Also what cause the drone and in cabin resonate? going catless or x-pipe or no resonators?
avex8 is offline  
0
Reply With Quote
      08-09-2011, 07:03 AM   #2
JOM3JO
Private First Class
 
Drives: e92 m3
Join Date: Mar 2010
Location: sydney

Posts: 161
iTrader: (0)

thats why i still have OEM system
JOM3JO is offline  
0
Reply With Quote
      08-09-2011, 07:30 AM   #3
nineonenine
Second Lieutenant
 
Drives: M3
Join Date: Jun 2011
Location: USA

Posts: 214
iTrader: (0)

I've got the UUC Corsa axle back and literally experience NO drone what so ever.
nineonenine is offline  
0
Reply With Quote
      08-09-2011, 07:31 AM   #4
Krozi
Deutsche Jung aus Kölle
 
Krozi's Avatar
 
Drives: 2008 E92 ///M3 Alpine White
Join Date: Oct 2009
Location: SoFla - Bonita Springs

Posts: 2,702
iTrader: (21)

Quote:
Originally Posted by JOM3JO View Post
thats why i still have OEM system

Remove yourself from this thread immediately.



OP, you might be able to reduce some drone by hacking up the OEM exhaust and replacing the front pipes with the first set of cats from the OEM exhaust.
__________________

2008 E92 ///M3 Alpine White//Fox Red//6MT//
Florida Bimmer - Join us on FaceBook!
Krozi is offline   Germany
0
Reply With Quote
      08-09-2011, 09:33 AM   #5
FVM3
Major General
 
FVM3's Avatar
 
Drives: e92 m3, f30 328i
Join Date: Sep 2010
Location: Los Angeles

Posts: 5,711
iTrader: (2)

i never care about drone.....the best way you go is back to oem
FVM3 is offline  
0
Reply With Quote
      08-09-2011, 09:55 AM   #6
geneatals
Ninja
 
geneatals's Avatar
 
Drives: 2011.5 E90 M3
Join Date: Dec 2007
Location: So Cal (SFV)

Posts: 3,202
iTrader: (2)

RPI makes silencer's (decreases the int and ext sound with a slight reduction in hp from what I remember) for their e60 m and non m systems, wonder if they can offer the same for their e9x m system....might be worth a call to rpi...
__________________
2011.5 E90 M3 AW l Black Novillo Leather | Carbon Fiber Leather Trim | ZCP | ZP2 | M-DCT | Navigation | Moonroof | 6FL l Pics/Mods
Retired: 2008 535i l AW l Black Dakota Leather l Bamboo Anthracite l ZPP l ZSP l 6FL
geneatals is offline   Philippines
0
Reply With Quote
      08-09-2011, 10:50 AM   #7
e92Mjunky
Second Lieutenant
 
Drives: New wife Alpine CF E92 M3
Join Date: Mar 2011
Location: Austin, TX

Posts: 272
iTrader: (0)

i have heard x-pipe only with factory exhaust..sounds good and has a few hp gains..
__________________

08' DCT CF Roof, nothing to fancy
custom magnaflow exhaust amd drop in filter
e92Mjunky is offline   United_States
0
Reply With Quote
      08-09-2011, 11:05 AM   #8
Straight Dave
Lieutenant
 
Straight Dave's Avatar
 
Drives: 2011.5 e92 m3
Join Date: Jun 2010
Location: Houston

Posts: 441
iTrader: (0)

x pipes do not create drone
Straight Dave is offline  
0
Reply With Quote
      08-09-2011, 11:32 AM   #9
Sean05
Putcha ang ganda...
 
Sean05's Avatar
 
Drives: 08 MR E92 M3
Join Date: Feb 2010
Location: Los Angeles, Brea CA.

Posts: 5,327
iTrader: (9)

Send a message via Yahoo to Sean05
put a resonator... that should lower it down... depends if yours going to put 4 or 2...the more resonator the the better in your case.... thats up to you.... also putting resonator will keep the noise a bit down inside the cabin but still keep the power that you want.

also you can put a 200 cel cat on the primary side and have a resonator on the back end. to keep the noise down a bit.

if you put the 200 cell cat and the resonator by the cat (like the oem xpipe with turner it will drone more than having the 200 cel cat on the primary...


this is just my experience with my AKRA slip on exhaust.. Akra ehxaust holds the noise and drone... not sure with your exhaust set up... they all depend on your axle back exhaust as well.
__________________
Sean05 is offline   Philippines
0
Reply With Quote
      08-09-2011, 11:34 AM   #10
EuroTrip
BMW FAN
 
EuroTrip's Avatar
 
Drives: 2011 E92 M3 DCT ZCP Mineral Wt
Join Date: Jan 2008
Location: Laguna Beach, CA

Posts: 687
iTrader: (5)

I think if it in very simple terms when it comes to drone.

The lower the price, the higher the drone.
EuroTrip is offline  
0
Reply With Quote
      08-09-2011, 12:47 PM   #11
kitw
Colonel
 
kitw's Avatar
 
Drives: 2015 MW M3/2014 Boxster S
Join Date: Jun 2007
Location: Bay Area, CA

Posts: 2,415
iTrader: (14)

^ except you'd be completely wrong.

The RPI GTM system is loud. Going stock midsection + TTP is a good option but it won't eliminate it completely. The Innotech is probably the best in this regard, even with the catless x pipe, closed, it's very quiet and drone free.

There is only so much you can do with the x pipe, if you still want power.
__________________

IMG_3969-Edit by kitw, on Flickr
kitw is offline  
0
Reply With Quote
      08-09-2011, 01:17 PM   #12
avex8
Captain
 
avex8's Avatar
 
Drives: 11 E92 M3, 13 X3 35i, 14 650i
Join Date: May 2011
Location: San Diego

Posts: 731
iTrader: (2)

how to reduce he low frequency resonance? The in cabin resonance bug me the most
avex8 is offline  
0
Reply With Quote
      08-09-2011, 01:37 PM   #13
Malek@MRF
BimmerPost Supporting Vendor

 
Malek@MRF's Avatar
 
Drives: E92 M3
Join Date: Jan 2008
Location: Irvine, California

Posts: 3,355
iTrader: (5)

Send a message via AIM to Malek@MRF
Quote:
Originally Posted by Sean05 View Post
put a resonator... that should lower it down... depends if yours going to put 4 or 2...the more resonator the the better in your case.... thats up to you.... also putting resonator will keep the noise a bit down inside the cabin but still keep the power that you want.

also you can put a 200 cel cat on the primary side and have a resonator on the back end. to keep the noise down a bit. .
1) Resonators do not reduce or remove drone, they are used to tune exhaust note frequency.

2) Catalysts do not remove drone, they simply muffle the overall sound because of restriction. This restriction also results in less rasp.

3) More resonators=more weight, more heat, and less power (slightly).
__________________

BMW PERFORMANCE SPECIALISTS. Suspension. Forced Induction. Brakes. Race Preparation. Service. Alignments.
OFFICIAL PARTNERS: Öhlins. KW Suspension. Brembo. AP Racing. ESS Tuning. iND Distribution. Turner Motorsport.
Facebook | Instagram | Yelp! | Flikr | Contact | YouTube
Malek@MRF is offline   United_States
0
Reply With Quote
      08-09-2011, 01:39 PM   #14
Malek@MRF
BimmerPost Supporting Vendor

 
Malek@MRF's Avatar
 
Drives: E92 M3
Join Date: Jan 2008
Location: Irvine, California

Posts: 3,355
iTrader: (5)

Send a message via AIM to Malek@MRF
Quote:
Originally Posted by jakerx8 View Post
how to reduce he low frequency resonance? The in cabin resonance bug me the most
This is not possible with resonators. Resonators are nothing but small bodied straight through mufflers. They will simply control some unwanted overtones in the sound, as long as the designer of the system knows how to implement it.

Cabin resonance is a result of piping design, muffler design and in some cases, both.
__________________

BMW PERFORMANCE SPECIALISTS. Suspension. Forced Induction. Brakes. Race Preparation. Service. Alignments.
OFFICIAL PARTNERS: Öhlins. KW Suspension. Brembo. AP Racing. ESS Tuning. iND Distribution. Turner Motorsport.
Facebook | Instagram | Yelp! | Flikr | Contact | YouTube
Malek@MRF is offline   United_States
0
Reply With Quote
      08-09-2011, 01:40 PM   #15
Sean05
Putcha ang ganda...
 
Sean05's Avatar
 
Drives: 08 MR E92 M3
Join Date: Feb 2010
Location: Los Angeles, Brea CA.

Posts: 5,327
iTrader: (9)

Send a message via Yahoo to Sean05
^ just my experience bro... all sounds different with different exhaust.... I had swap couple xpipe with or without resonator the noted above is what i experience... weather resonators does or not add drone it did to my old set up...

But maybe having an AKRA SLIP ON probably gave it that results
__________________
Sean05 is offline   Philippines
0
Reply With Quote
      08-09-2011, 01:42 PM   #16
Malek@MRF
BimmerPost Supporting Vendor

 
Malek@MRF's Avatar
 
Drives: E92 M3
Join Date: Jan 2008
Location: Irvine, California

Posts: 3,355
iTrader: (5)

Send a message via AIM to Malek@MRF
Quote:
Originally Posted by Sean05 View Post
^ just my experience bro... all sounds different with different exhaust.... I had swap couple xpipe with or without resonator the noted above is what i experience... weather resonators does or not add drone it did to my old set up...

But maybe having an AKRA SLIP ON probably gave it that results
An Akrapovic rear section is very silent and well designed, thats where most of your sound and resonance control is being done, not through a couple resonators.
__________________

BMW PERFORMANCE SPECIALISTS. Suspension. Forced Induction. Brakes. Race Preparation. Service. Alignments.
OFFICIAL PARTNERS: Öhlins. KW Suspension. Brembo. AP Racing. ESS Tuning. iND Distribution. Turner Motorsport.
Facebook | Instagram | Yelp! | Flikr | Contact | YouTube
Malek@MRF is offline   United_States
0
Reply With Quote
      08-09-2011, 01:46 PM   #17
avex8
Captain
 
avex8's Avatar
 
Drives: 11 E92 M3, 13 X3 35i, 14 650i
Join Date: May 2011
Location: San Diego

Posts: 731
iTrader: (2)

Quote:
Originally Posted by Malekreza11 View Post
An Akrapovic rear section is very silent and well designed, thats where most of your sound and resonance control is being done, not through a couple resonators.
i see... what if i put the oem cat and x -pipe back and just keep the axle back. Would that be a lot quieter?
avex8 is offline  
0
Reply With Quote
      08-09-2011, 01:50 PM   #18
Malek@MRF
BimmerPost Supporting Vendor

 
Malek@MRF's Avatar
 
Drives: E92 M3
Join Date: Jan 2008
Location: Irvine, California

Posts: 3,355
iTrader: (5)

Send a message via AIM to Malek@MRF
Quote:
Originally Posted by jakerx8 View Post
i see... what if i put the oem cat and x -pipe back and just keep the axle back. Would that be a lot quieter?
Yes, it would be far quieter because the factory midsection utilizes 4 catalysts and 2 resonators and a merge balance tube what many refer to as an X-pipe.
__________________

BMW PERFORMANCE SPECIALISTS. Suspension. Forced Induction. Brakes. Race Preparation. Service. Alignments.
OFFICIAL PARTNERS: Öhlins. KW Suspension. Brembo. AP Racing. ESS Tuning. iND Distribution. Turner Motorsport.
Facebook | Instagram | Yelp! | Flikr | Contact | YouTube
Malek@MRF is offline   United_States
0
Reply With Quote
      08-09-2011, 02:05 PM   #19
avex8
Captain
 
avex8's Avatar
 
Drives: 11 E92 M3, 13 X3 35i, 14 650i
Join Date: May 2011
Location: San Diego

Posts: 731
iTrader: (2)

Quote:
Originally Posted by Malekreza11 View Post
Yes, it would be far quieter because the factory midsection utilizes 4 catalysts and 2 resonators and a merge balance tube what many refer to as an X-pipe.
I got your point. But i really want to have the primary cat deleted, so i can get most power out of the car. But i don't know if it will help reduce the in cabin resonance by having the tuner test pipe and keep the oem x-pipe (2 cat and 2 resonators).
avex8 is offline  
0
Reply With Quote
      08-09-2011, 02:10 PM   #20
Malek@MRF
BimmerPost Supporting Vendor

 
Malek@MRF's Avatar
 
Drives: E92 M3
Join Date: Jan 2008
Location: Irvine, California

Posts: 3,355
iTrader: (5)

Send a message via AIM to Malek@MRF
Quote:
Originally Posted by jakerx8 View Post
I got your point. But i really want to have the primary cat deleted, so i can get most power out of the car. But i don't know if it will help reduce the in cabin resonance by having the tuner test pipe and keep the oem x-pipe (2 cat and 2 resonators).
The OEM midsection is actually VERY loud with the primaries deleted mainly because of the reason that the merge between the two tubes is very small.

We have cut the stock system apart to see where its short comings are.

The merge section is very small, and the larger the merge the tighter the sound.
__________________

BMW PERFORMANCE SPECIALISTS. Suspension. Forced Induction. Brakes. Race Preparation. Service. Alignments.
OFFICIAL PARTNERS: Öhlins. KW Suspension. Brembo. AP Racing. ESS Tuning. iND Distribution. Turner Motorsport.
Facebook | Instagram | Yelp! | Flikr | Contact | YouTube
Malek@MRF is offline   United_States
0
Reply With Quote
      08-09-2011, 02:12 PM   #21
Sean05
Putcha ang ganda...
 
Sean05's Avatar
 
Drives: 08 MR E92 M3
Join Date: Feb 2010
Location: Los Angeles, Brea CA.

Posts: 5,327
iTrader: (9)

Send a message via Yahoo to Sean05
Quote:
Originally Posted by Malekreza11 View Post
An Akrapovic rear section is very silent and well designed, thats where most of your sound and resonance control is being done, not through a couple resonators.
question to you now though is WHY

setup one
1. xpipe with 200 cel secondary cat with resonator

setup two
2. xpipe with 200 cel primary cat with resonator

now why is set up one is louder than set up 2 also setup one drones more than setup 2...

also heres is what i have before as well

setup one
1. x pipe with no cat and res...

setup two
2. xpipe with 4 resonator no cats

now why is my exhaust drones more on setup one than 2 if you say that resonator doesnt reduce any drone or remove drone?

just curious cause it did to my set up...

in the end i decided to have a 200 primary cat with rear section resonator to avoid the drone which is a perfect match for the AKRA...

IM GUESSING IF THAT IS IT BECAUSE OF THE AKRA EXHAUST?

this is just my own experience having 3 different xpipe i had used.
__________________
Sean05 is offline   Philippines
0
Reply With Quote
      08-09-2011, 02:28 PM   #22
Malek@MRF
BimmerPost Supporting Vendor

 
Malek@MRF's Avatar
 
Drives: E92 M3
Join Date: Jan 2008
Location: Irvine, California

Posts: 3,355
iTrader: (5)

Send a message via AIM to Malek@MRF
Quote:
Originally Posted by Sean05 View Post
question to you now though is WHY

setup one
1. xpipe with 200 cel secondary cat with resonator

setup two
2. xpipe with 200 cel primary cat with resonator

now why is set up one is louder than set up 2 also setup one drones more than setup 2...

also heres is what i have before as well

setup one
1. x pipe with no cat and res...

setup two
2. xpipe with 4 resonator no cats

now why is my exhaust drones more on setup one than 2 if you say that resonator doesnt reduce any drone or remove drone?

just curious cause it did to my set up...

in the end i decided to have a 200 primary cat with rear section resonator to avoid the drone which is a perfect match for the AKRA...

IM GUESSING IF THAT IS IT BECAUSE OF THE AKRA EXHAUST?

this is just my own experience having 3 different xpipe i had used.
The answer to all these questions is rather simple actually, restriction. The point of the "x-pipe" is to add power and reduce weight substantially, surely its not for cosmetics because its not a visible item.

Adding all those extra components in the system is creating restriction (especially the catalysts), creating additional heat and adding substantial amount of weight. I would like to reiterate that the purpose of a mid-section is to add power as much as possible.

The best way to test your theory is to put straight through piping as your rear section, and then messing with the multiple mid-section setups as this will provide an escape for the exhaust gasses and pressure wave through a controlled tube rather than just letting it dump out right after the midsection. Eliminate the variable, which would be the behavior of the rear section and make it straight through, muffler-less, tubing exiting the rear bumper.

High end exhaust systems are, well, systems because they are designed to work together systematically. There are some well thought out, well crafted systems out there, as well as some terrible ones.

The Akrapovic is a good system, hence the price and popularity.
__________________

BMW PERFORMANCE SPECIALISTS. Suspension. Forced Induction. Brakes. Race Preparation. Service. Alignments.
OFFICIAL PARTNERS: Öhlins. KW Suspension. Brembo. AP Racing. ESS Tuning. iND Distribution. Turner Motorsport.
Facebook | Instagram | Yelp! | Flikr | Contact | YouTube
Malek@MRF 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 06:09 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