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

Go Back   BMW M3 and BMW M4 Forum > BMW F80 M3 / F82 M4 Technical Topics > Engine / Drivetrain / Exhaust / Bolt-ons / Tuning

Post Reply
 
Thread Tools Search this Thread
      10-03-2019, 07:22 AM   #45
RevNev
First Lieutenant
154
Rep
331
Posts

Drives: X3 M40i
Join Date: Oct 2018
Location: Australia

iTrader: (0)

Quote:
Originally Posted by MR_X View Post
Would like to see the dyno graph for that. Very interested in this. An actual drive by of the exhaust would be nice also. Also, what are the dimensions of the resonators?
Resonators are 12" long 4" diameter. I'll post the dyno sheet soon.
Appreciate 0
      10-03-2019, 09:39 AM   #46
bobbyh907
Private
18
Rep
57
Posts

Drives: 2015 M3 Alpine White
Join Date: Jul 2018
Location: Alaska

iTrader: (0)

Here's what I did. 5" oval midpipe. In the video first rev is valves closed, second is open. Definitely less rasp with the valves open. Need to get a better microphone besides a cell phone recording to really tell though.
Name:  received_440590249888013.jpg
Views: 1054
Size:  218.4 KB

Appreciate 1
      10-03-2019, 05:03 PM   #47
PayamFSU
Captain
PayamFSU's Avatar
151
Rep
789
Posts

Drives: 2018 F80 ZCP YMB
Join Date: Apr 2015
Location: Gainesville, FL

iTrader: (3)

Quote:
Originally Posted by bobbyh907 View Post
Here's what I did. 5" oval midpipe. In the video first rev is valves closed, second is open. Definitely less rasp with the valves open. Need to get a better microphone besides a cell phone recording to really tell though.
Attachment 2153185

That's raspy as hell lol
__________________

2018 F80 ZCP 6MT YMB/SO
2015 F82 M4 6MT AW/SO - SOLD
Appreciate 2
      10-03-2019, 05:50 PM   #48
Andrae26
Captain
United_States
363
Rep
686
Posts

Drives: Sakhir M4
Join Date: May 2018
Location: San Diego

iTrader: (0)

Quote:
Originally Posted by PayamFSU View Post
Quote:
Originally Posted by bobbyh907 View Post
Here's what I did. 5" oval midpipe. In the video first rev is valves closed, second is open. Definitely less rasp with the valves open. Need to get a better microphone besides a cell phone recording to really tell though.
Attachment 2153185

That's raspy as hell lol
I though it was just me. Sounds very raspy.
Appreciate 0
      10-03-2019, 07:56 PM   #49
Djdnav
Private First Class
103
Rep
163
Posts

Drives: F80 M3
Join Date: Jul 2018
Location: Central FL

iTrader: (3)

Quote:
Originally Posted by Andrae26 View Post
I though it was just me. Sounds very raspy.
Not just you, it sounds awful.
__________________
///M3
Appreciate 1
      10-03-2019, 09:02 PM   #50
RevNev
First Lieutenant
154
Rep
331
Posts

Drives: X3 M40i
Join Date: Oct 2018
Location: Australia

iTrader: (0)

Quote:
Originally Posted by PayamFSU View Post
That's raspy as hell lol
It's raspy because there's no mufflers in the oval midpipe and there's no room for any either. Single midpipes and x-pipe type collectors reduces the farty sound and resonators remove the raspiness.
Appreciate 0
      10-07-2019, 04:22 PM   #51
MR_X
Old guy
85
Rep
128
Posts

Drives: tricycle
Join Date: Dec 2009
Location: HR, Va

iTrader: (0)

Waiting on a drive by video.
Appreciate 0
      10-12-2019, 03:54 PM   #52
RevNev
First Lieutenant
154
Rep
331
Posts

Drives: X3 M40i
Join Date: Oct 2018
Location: Australia

iTrader: (0)

Quote:
Originally Posted by MR_X View Post
Waiting on a drive by video.
I need to get out of town a bit to do a drive by video properly. If the cops catch you at the speed it takes to hear a couple of gear changes at 7000rpm, aside from blowing your drivers licence, they impound the car for 28 days. Other than tracks days, it's pretty hard to enjoy the power of cars like this and avoid the cops and dashcam videos from other cars in the suburbs.

Even with 4 resonators in the midpipe and catless downpipes, it's lot louder than stock with the valves open with a deeper and smoother note. With the valves closed, it's quieter than stock at cruising speed and a little bit louder on acceleration. Not sure what the hype's about exhaust fume smell with no cats. There's no smell in the car and it's only a minor fume increase running in the shed with door closed. It's not fumy to the extent of emphasising the cats are deleted on this car.

Last edited by RevNev; 10-12-2019 at 04:17 PM..
Appreciate 1
ra2289108.00

      10-12-2019, 04:01 PM   #53
ra2289
Second Lieutenant
108
Rep
219
Posts

Drives: '11 E92 M3
Join Date: May 2013
Location: I'm Ron Burgundy?

iTrader: (0)

Quote:
Originally Posted by RevNev View Post
Quote:
Originally Posted by MR_X View Post
Waiting on a drive by video.
I need to get out of town a bit to do a drive by video properly. If the cops catch you at the speed it takes to hear a couple of gear changes at 7000rpm, aside from blowing your drivers licence, they impound the car for 28 days. Other than tracks days, it's pretty hard to enjoy the power of cars like this and avoid the cops and dashcam videos from other cars in the suburbs.
Well kudos for thinking of a way to do it properly without putting yourself and/or other people in a bad spot.
Appreciate 0
      10-12-2019, 07:25 PM   #54
X.X.I.V
First Lieutenant
X.X.I.V's Avatar
United_States
27
Rep
378
Posts

Drives: 16 F80
Join Date: Sep 2009
Location: Glenview, IL

iTrader: (0)

Quote:
Originally Posted by ra2289 View Post
Quote:
Originally Posted by RevNev View Post
Quote:
Originally Posted by MR_X View Post
Waiting on a drive by video.
I need to get out of town a bit to do a drive by video properly. If the cops catch you at the speed it takes to hear a couple of gear changes at 7000rpm, aside from blowing your drivers licence, they impound the car for 28 days. Other than tracks days, it's pretty hard to enjoy the power of cars like this and avoid the cops and dashcam videos from other cars in the suburbs.
Well kudos for thinking of a way to do it properly without putting yourself and/or other people in a bad spot.
Quote:
Originally Posted by ra2289 View Post
Quote:
Originally Posted by RevNev View Post
Quote:
Originally Posted by MR_X View Post
Waiting on a drive by video.
I need to get out of town a bit to do a drive by video properly. If the cops catch you at the speed it takes to hear a couple of gear changes at 7000rpm, aside from blowing your drivers licence, they impound the car for 28 days. Other than tracks days, it's pretty hard to enjoy the power of cars like this and avoid the cops and dashcam videos from other cars in the suburbs.
Well kudos for thinking of a way to do it properly without putting yourself and/or other people in a bad spot.
Is there a parts list for this custom exhaust?
Appreciate 0
      10-13-2019, 09:51 AM   #55
BB6
Private First Class
United_States
38
Rep
118
Posts

Drives: M6
Join Date: Feb 2017
Location: Illinois

iTrader: (0)

Quote:
Originally Posted by RevNev View Post
Here's an M4 GT4 race car with an Eisenmann X-pipe, resonators on the back and sounds great

The point is; if you don't join the midpipes in an X or collector and the exhaust doesn't pass through resonators with the valves open like most aftermarket systems, they'll never sound good and will retain the farty and raspy sound.

What resonators is this thing running, it sounds amazing
__________________
BM3 (OTS STG2-93), Fabworx DP, Dss Axles, R888R
Appreciate 0
      10-14-2019, 09:28 AM   #56
spool twice
Rainbow Racer
spool twice's Avatar
United_States
204
Rep
1,538
Posts

Drives: BMW M4cs
Join Date: Sep 2010
Location: Tampa Bay, FL Area

iTrader: (7)

Garage List
2019 M4cs  [0.00]
I'll be modifying my pipes this week at the resonator and back to the muffler area getting rid of that crossover pipe and re-routing the rear bank exhausts to create additional piping to equalize the pulses before they merge at a new crossover location. Will send sound clips, regardless of how it sounds.

In theory, it should give it a smoother vrooooom exhaust sound (N54-like) by balancing out the pulses on each bank.
Appreciate 0
      10-14-2019, 10:39 AM   #57
MR_X
Old guy
85
Rep
128
Posts

Drives: tricycle
Join Date: Dec 2009
Location: HR, Va

iTrader: (0)

Quote:
Originally Posted by spool twice View Post
I'll be modifying my pipes this week at the resonator and back to the muffler area getting rid of that crossover pipe and re-routing the rear bank exhausts to create additional piping to equalize the pulses before they merge at a new crossover location. Will send sound clips, regardless of how it sounds.

In theory, it should give it a smoother vrooooom exhaust sound (N54-like) by balancing out the pulses on each bank.

Been thinking about something similar but I think the issue is before the stock h pipe. The front downpipe is the longest and it connects to the inside exhaust pipe which is also the longest. I was thinking of putting an x pipe right after the first bend and before the second bend, kind of like the OP did with hope of flipping the exhaust flow to the other side.

That is my thought on this but would like to see how you go about this.
Appreciate 0
      10-14-2019, 04:11 PM   #58
spool twice
Rainbow Racer
spool twice's Avatar
United_States
204
Rep
1,538
Posts

Drives: BMW M4cs
Join Date: Sep 2010
Location: Tampa Bay, FL Area

iTrader: (7)

Garage List
2019 M4cs  [0.00]
You would still need to lengthen the back bank pipe before they crossover, space is too limited to me, but if you can find a solution that would be awesome!

In my description, resonator is the OE H-pipe/resonator combo. There is so much limited space up front that the only option i can see is removing the resonator/h-pipe altogether and the pipes leading all the way to the valve actuators and using that space to somehow add length to the back-bank (drivers side) pipe and then fabricating a new h/x-pipe once both are adequately even. Unfortunately this will mean the crossover pipe is further rear, but in a turbocharged car, the location doesn't matter as much as an NA car.

Im trying to avoid removing the secondary cats (just a personal preference)

Last edited by spool twice; 10-14-2019 at 04:55 PM..
Appreciate 0
      10-15-2019, 03:58 PM   #59
MR_X
Old guy
85
Rep
128
Posts

Drives: tricycle
Join Date: Dec 2009
Location: HR, Va

iTrader: (0)

Actually I wonder if the downpipes can be redesign to be flipped? Meaning the front back comes out on the passenger side instead of the drivers side.
Appreciate 0
      10-15-2019, 05:41 PM   #60
Andrew@ActiveAutowerke
BimmerPost Supporting Vendor
Andrew@ActiveAutowerke's Avatar
953
Rep
5,193
Posts


Drives: 17 F80 M3 YASSS
Join Date: Dec 2011
Location: Miami Fl

iTrader: (5)

Still find my exhaust to be the best sounding that I have heard.






Last edited by Andrew@ActiveAutowerke; 10-15-2019 at 05:48 PM..
Appreciate 0
      10-15-2019, 06:06 PM   #61
Schultz28
First Lieutenant
United_States
112
Rep
314
Posts

Drives: 2015 F80 M3
Join Date: Oct 2016
Location: Campbell, CA

iTrader: (1)

This is really how to make your car sound good. (Single Turbo)

Appreciate 2
phoenx162.00

      10-15-2019, 06:12 PM   #62
ntgarage44
Captain
ntgarage44's Avatar
United_States
752
Rep
901
Posts

Drives: '17 M3 Mineral White 6MT
Join Date: Aug 2018
Location: Chicago

iTrader: (2)

Quote:
Originally Posted by Schultz28 View Post
This is really how to make your car sound good. (Single Turbo)

Was waiting for this haha.
Appreciate 1
      10-15-2019, 08:38 PM   #63
spool twice
Rainbow Racer
spool twice's Avatar
United_States
204
Rep
1,538
Posts

Drives: BMW M4cs
Join Date: Sep 2010
Location: Tampa Bay, FL Area

iTrader: (7)

Garage List
2019 M4cs  [0.00]
Quote:
Originally Posted by MR_X View Post
Actually I wonder if the downpipes can be redesign to be flipped? Meaning the front back comes out on the passenger side instead of the drivers side.
Definitely, the S58 actually has them swapped. There is room and options to equalize the pipes in the downpipes if you are crafty, but it may not be practical for installation reasons.
Appreciate 0
      10-15-2019, 08:41 PM   #64
MR_X
Old guy
85
Rep
128
Posts

Drives: tricycle
Join Date: Dec 2009
Location: HR, Va

iTrader: (0)

Quote:
Originally Posted by Schultz28 View Post
This is really how to make your car sound good. (Single Turbo)

Is that SMOG legal? Asking for a friend.
Appreciate 0
      10-15-2019, 08:42 PM   #65
spool twice
Rainbow Racer
spool twice's Avatar
United_States
204
Rep
1,538
Posts

Drives: BMW M4cs
Join Date: Sep 2010
Location: Tampa Bay, FL Area

iTrader: (7)

Garage List
2019 M4cs  [0.00]
Quote:
Originally Posted by Schultz28 View Post
This is really how to make your car sound good. (Single Turbo)

Definitely! This is a traditional i-6 exhaust sound when everything is equalized. The S55 can sound good, it's just the differences in OE pipe lengths prevents this, and the aftermarket options aren't helping the sound, just amplifying the ugly sound. Why this is? Idk, sad (shame actually, they all sound like shit) that it's been 4 or 5 years, none of the aftermarket guys want a good sounding S55, they made their $$ so why bother? It seems like a diy is the way to go to get a decent and traditional smooth i6 exhaust sound.


....on a side note. Ive been speaking with a member here and we share similar thoughts. He actually went and equalized his pipes, and sent me a video. It sounds very nice, smooth in tone, and changes pitch when revved, like the exhaust is having a happy time revving, exactly how a sporty car should sound like. I'll let him post if he feels like he needs to, but I'll be crafting something similar but not exact.

Last edited by spool twice; 10-15-2019 at 08:49 PM..
Appreciate 0
      10-16-2019, 10:09 AM   #66
ntgarage44
Captain
ntgarage44's Avatar
United_States
752
Rep
901
Posts

Drives: '17 M3 Mineral White 6MT
Join Date: Aug 2018
Location: Chicago

iTrader: (2)

Quote:
Originally Posted by spool twice View Post
The S55 can sound good, it's just the differences in OE pipe lengths prevents this, and the aftermarket options aren't helping the sound, just amplifying the ugly sound. Why this is? Idk, sad (shame actually, they all sound like shit) that it's been 4 or 5 years, none of the aftermarket guys want a good sounding S55, they made their $$ so why bother? It seems like a diy is the way to go to get a decent and traditional smooth i6 exhaust sound.

I've never been a business owner, but personally, I'd attribute it to laziness or unwillingness to put in the R&D costs, in general. I'd argue that the vast majority of cars that companies design exhausts for aren't presented with this challenge. Most cars that are sold have either 1 exhaust manifold/downpipe to deal with, or are longitudinally mounted V engines. So the natural thing to do would be to have an equal length exhaust for all of these engine layouts right from the get go.

The S55 engine is unique in the sense that it has a twin turbo longitudinally mounted inline 6 with the turbos in parallel. I could be wrong, because I'm not too well informed on the new MB inline 6, but as far as I know, this is the only engine of its type currently on sale in a production car at the moment. BMW made a decision for unequal length downpipes, I'm sure for packaging reasons, and it gives this engine its unique sound, for better or worse. Which brings me to my point of this post.

When aftermarket exhaust manufacturers are designing exhausts for a new car, I can only imagine that a high priority is the cost effectiveness, with the focus on the mufflers and resonators. Changing the actual design of the stock exhaust with methods like unequal length pipes to equalize the pulses is probably not high on this list, because it's not usually something these companies run into and "need" to fix. It's usually easier to make something louder and "deeper" as it's always marketed. For this reason, I give huge props to Active Autowerke for actually coming up with something unique. True dual exhausts always seem to market better, regardless of how they perform, and doing something counter intuitive like the AA midpipe in the pursuit of tone was an awesome development in my opinion. It's probably the best tone you're going to get from the standard exhaust configuration.

As you've mentioned, the next step is to find a way to equalize the length of the pipes before a merge given the packaging constraints. Maybe it can be done, maybe not. But the first manufacturer to bring such a system to market could charge more than Akrapovic and they wouldn't be able to keep the system in stock.
Appreciate 0
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



All times are GMT -5. The time now is 11:41 PM.




f80post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, 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