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


Go Back   ZPOST > BMW Z4 Technical Talk > Engine, Exhaust, Drivetrain Modifications
  TireRack

SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS!
Post Reply
 
Thread Tools Search this Thread
      07-18-2018, 01:05 AM   #1
ZeD4Mr
Captain
ZeD4Mr's Avatar
Canada
188
Rep
956
Posts

Drives: MR
Join Date: Dec 2009
Location: B.C. Canada

iTrader: (15)

I've met a guy that built a J test pipe to a Z4M with RPi. He said it reduces the idling decibel from almost 100 to 88dB. The volume of the sound and tone stays the same but drone is minimized next to none.

Since he loved the RPi sound the best, out of all the other exhaust for the Z4M but can't bear with the drone, this is his solution with good results.

thoughts?
Attached Images
 
__________________
.
.

Supersprint Powerloops, SKYER CF spoiler, AS SSK, AA tune, Vibra Technics, Eventuri, Stoptech lines & pads, RE trans mount, OE hardtop
Appreciate 0
      07-18-2018, 07:31 AM   #2
RABAUKE
Rear Admiral
RABAUKE's Avatar
Canada
4213
Rep
1,399
Posts

Drives: Porsche 993, 2014 MB GLK
Join Date: Jan 2015
Location: The Golden Horseshoe, Ontario

iTrader: (0)

I guess you'd really have to hear it to judge if it cured the problem of drone and sounded better quieter at idle. Can you post a video?
Appreciate 0
      07-18-2018, 09:17 AM   #3
rockstar93
First Lieutenant
rockstar93's Avatar
Canada
138
Rep
307
Posts

Drives: E86 Z4MC; E92 M3
Join Date: Jun 2015
Location: Mississauga, Ontario

iTrader: (5)

Garage List
Isn't the first time I've heard of this, and I have heard that it works very well. Called a Helmholtz chamber. Here's more pictures:

https://www.facebook.com/pg/flowauto...60298500704472













__________________
E46 M3 Coupe 6MT Jet Black/Cinnamon GONE
E85 Z4M Roadster Imola Red/Black GONE
E90 M3 Sedan 6MT Jerez Black/Fox Red GONE
E86 Z4M Coupe Interlagos Blue/Black
E92 M3 Coupe 6MT Interlagos Blue/Fox Red

Last edited by rockstar93; 07-18-2018 at 09:59 AM.
Appreciate 0
      07-18-2018, 09:49 AM   #4
racerbruce
Racerbruce
racerbruce's Avatar
85
Rep
554
Posts

Drives: 2007 Z4MR Imola Red
Join Date: Dec 2009
Location: Seattle

iTrader: (1)

Exhaust systems that are professionally engineered typically take into account for equal length headers (or not), length of piping to the mufflers, CATS, resonators, exhaust gas pulses, etc.

Curious how this app affects overall exhaust performance.
__________________
Racerbruce
OZ Rims / Bilstein B8 Struts & Shocks / Eibach Pro-Kit Springs / ZHP Control Arms / RE Diablo Exhaust / RPi Air Intake / BMC Air Filter / CDV / 3M Paint Protection / TMS CF Grilles / TK CF Mirrors / Skyer CF Spoiler / CF Antenna / RE Trans Mounts / M Pedals & Dead Pedal / WeissLicht LED Rear Turn Signal Lamps / CoCo Floor Mats / #748 of 3,041
Appreciate 0
      07-23-2018, 12:47 PM   #5
///Mcoupe
New Member
0
Rep
5
Posts

Drives: 2007 M Coupe
Join Date: May 2018
Location: Montreal , Canada

iTrader: (0)

So is the added piece just a resonator thats been capped ?
Appreciate 0
      07-24-2018, 03:06 PM   #6
RossBMWZseries
Captain
United_States
89
Rep
745
Posts

Drives: '11 E92 328i LCI & '06 Z4MR
Join Date: Jun 2014
Location: San Juan TX

iTrader: (1)

Garage List
Am I the only one not really bothered by the drone the RPI's make? I drive it like a grandma, sometimes like a grandma on an energy drink (not any more aggressive because rod bearings), and i just happen to always enjoy the sound at any given RPM, it's glorious!
__________________
2011 BMW 328i E92 LCI
2006 BMW Z4 M Roadster
2013 BMW S1000RR R.I.P.
1998 BMW Z3 Roadster 1.9L SOLD
Appreciate 0
      07-24-2018, 04:11 PM   #7
ZeD4Mr
Captain
ZeD4Mr's Avatar
Canada
188
Rep
956
Posts

Drives: MR
Join Date: Dec 2009
Location: B.C. Canada

iTrader: (15)

Quote:
Originally Posted by ///Mcoupe View Post
So is the added piece just a resonator thats been capped ?
Yes but the length of the pipe is the key as well as the capped resonator. They were able to weld it to hide the resonator behind the smaller tip so they are not as visible once installed. They try various length based on calculation and this works the best.

I will be able to hear this car next month and I'll report back.

Quote:
Originally Posted by RossBMWZseries View Post
Am I the only one not really bothered by the drone the RPI's make? I drive it like a grandma, sometimes like a grandma on an energy drink (not any more aggressive because rod bearings), and i just happen to always enjoy the sound at any given RPM, it's glorious!
Ross, Ear wax checked? I'll be recording trunk mounted video soon to compare with all other exhausts I've had to our Youtube Channel. It is very boomy at the wrong rpm.
__________________
.
.

Supersprint Powerloops, SKYER CF spoiler, AS SSK, AA tune, Vibra Technics, Eventuri, Stoptech lines & pads, RE trans mount, OE hardtop
Appreciate 0
      08-04-2018, 03:27 PM   #8
TurboDream17
///M Enthusiast
TurboDream17's Avatar
United_States
27
Rep
68
Posts

Drives: '07 Z4M Coupe
Join Date: Dec 2011
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by racerbruce View Post
Exhaust systems that are professionally engineered typically take into account for equal length headers (or not), length of piping to the mufflers, CATS, resonators, exhaust gas pulses, etc.

Curious how this app affects overall exhaust performance.
Since the end of the pipe is capped, the exhaust performance will be exactly the same. It's like having an electric circuit with an open going to nowhere -- all of the current/exhaust gas will flow out the only way it can.
__________________
///M Coupe - Volk TE37's 19x10.5R +22 19x8.5F +30 | KW V3 w/ Clubsport rear springs | RPi exhaust | Autosolutions SSK | RE transmission mounts | RE RSM's | Vibra-Technics engine mounts | RPi scoop | RPi skid plates | Tekarbon spoiler | Apex wheel studs | Blox burnt titanium lug nuts | UUC Front 27mm Swaybarbarian | Status Gruppe adjustable front links | EAS Blacked out kidneys | Full Beisan Vanos Refresh
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 -4. The time now is 09:32 AM.




zpost
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, 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