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
 
Steve Thomas BMW
Post Reply
 
Thread Tools Search this Thread
      04-06-2012, 05:21 PM   #1
Tomislav
Panty Schtuffer
 
Drives: 2008 E92 M3 Coupe
Join Date: Aug 2011
Location: Melbourne

Posts: 258
iTrader: (0)

Garage List
2008 E92 M3  [0.00]
Has anyone done a H-Pipe instead of an X-Pipe?

Why the preference of one to another?
__________________
.: 2010 E71 X6M - stock, daily driver, towcar :.
.: 2008 E92 M3 - 6MT, Carbon Roof, Eibach Springs, Megan Axle Back exhaust :.
.: 1997 E36 323i Frankenstein - too much to list, track whore, stripped, caged, MoTeC, S85B50 :.
Tomislav is offline   Australia
0
Reply With Quote
      04-06-2012, 05:49 PM   #2
Sean05
Putcha ang ganda...
 
Sean05's Avatar
 
Drives: 08 MR E92 M3
Join Date: Feb 2010
Location: Los Angeles, Brea CA.

Posts: 5,287
iTrader: (9)

Send a message via Yahoo to Sean05
The only one i know of is akra uses H and X pipe on the evo
Sean05 is offline   Philippines
0
Reply With Quote
      04-06-2012, 06:30 PM   #3
1MOREMOD
2014 Track Days - 6|Ridge 1:54:61|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,715
iTrader: (5)

my understanding of it is that an H pipe allows some equalization of pressure from side to side thus reducing backpressure to a small degree but an X pipe brings the two sides together allowing scavaging of exhaust gases from the other side creating a much greater pressure drop hence freer flowing exhaust.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      04-06-2012, 08:38 PM   #4
Raptor251
ESS Dreaming
 
Raptor251's Avatar
 
Drives: 2011.5 e92 m3/Ford Raptor 6.2
Join Date: Jan 2011
Location: San Diego

Posts: 870
iTrader: (1)

Akra has both!
Raptor251 is offline   United_States
0
Reply With Quote
      04-07-2012, 03:54 AM   #5
e90m3japan
Second Lieutenant
 
e90m3japan's Avatar
 
Drives: e90 m3 melbourne Red Metallic
Join Date: May 2009
Location: Yokohama,Japan and El Paso,Texas

Posts: 226
iTrader: (2)

I have amuse/ericsson full exhaust set-up with H and X pipe.
less sucking sound when releasing the throttle.
__________________
e90 m3 melbourne red metallic, "One and Only" e90 sedan Amuse Ericsson full exhaust(new model)with custom spec, Afe intake with stock box,piano black trim, blackline tail, HRE P40 9x19,10.5x19
e90m3japan is offline   Japan
0
Reply With Quote
      04-07-2012, 06:37 AM   #6
1MOREMOD
2014 Track Days - 6|Ridge 1:54:61|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,715
iTrader: (5)

Most of us probably like a sucking sound!
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      04-07-2012, 12:40 PM   #7
kitw
Colonel
 
kitw's Avatar
 
Drives: 2015 MW M3/2011 E90 M3
Join Date: Jun 2007
Location: Bay Area, CA

Posts: 2,339
iTrader: (14)

Quote:
Originally Posted by chriszeh View Post
my understanding of it is that an H pipe allows some equalization of pressure from side to side thus reducing backpressure to a small degree but an X pipe brings the two sides together allowing scavaging of exhaust gases from the other side creating a much greater pressure drop hence freer flowing exhaust.
No, they function the same way. Just different ways of tuning the scavenging, you can really only vary the position and size of an X pipe, where you can vary the width, position and size of an H pipe. Akrapovic's Evolution (and Gt4) midpipe use both X and H pipes. I haven't seen a significant difference, I ran both the Akrapovic and Challenge mid pipes and they both work pretty similarly and sound similar too.
kitw is offline  
0
Reply With Quote
      04-07-2012, 01:32 PM   #8
crabman
Captain
 
Drives: M3
Join Date: Dec 2011
Location: WA

Posts: 669
iTrader: (0)

Quote:
Originally Posted by chriszeh View Post
Most of us probably like a sucking sound!
lol, that one almost went by me.
__________________
2012 E92 Space Grey with fox red/black/black, comp, premium, DCT, premium sound, sirius, heated seats.
crabman is offline  
0
Reply With Quote
      04-07-2012, 02:44 PM   #9
m3an
Banned
 
m3an's Avatar
 
Drives: M3
Join Date: Oct 2010
Location: South Florida

Posts: 1,611
iTrader: (2)

there's some good articles to be found if your search re: h-pipes vs. x-pipes on v8 engines. Basically the idea behind both is to equalize the constantly changing pressure/velocity in each bank. The x-pipe design forces the cross-over whereas the h-pipe using the exhaust own scavenging to pull exhaust from one pipe to the other to equalize pressure.
m3an is offline  
0
Reply With Quote
      04-07-2012, 02:45 PM   #10
E90///M3`
Major General
 
Drives: 2008 E90M3
Join Date: Jan 2009
Location: Daly City -4- Work///Camarillo is Home

Posts: 5,278
iTrader: (3)

Garage List
2008 BMW E90 M3  [3.80]
Quote:
Originally Posted by e90m3japan View Post
I have amuse/ericsson full exhaust set-up with H and X pipe.
less sucking sound when releasing the throttle.
this sounds interesting and i'd like to hear the sound as well as know any whp numbers you may have gained.
__________________
- Jason P
:Have: 08 E90M3, Varis VRS Front Lip, LS3, ESS Supercharger, Arqray Exhaust, Neez Wheels
:Want: VRS Carbon GT Wing & Cooling Bonnet, LCI Taillights
:Videos: EnvyRidesTV, GPR 1, GPR 2, GPR 3, ///MFEST
E90///M3` is offline   Philippines
0
Reply With Quote
      04-07-2012, 02:45 PM   #11
m3an
Banned
 
m3an's Avatar
 
Drives: M3
Join Date: Oct 2010
Location: South Florida

Posts: 1,611
iTrader: (2)

it would be interesting to see a test done with all other things equal and just swapping the x-section for an h to observe the power difference
m3an is offline  
0
Reply With Quote
      04-07-2012, 06:35 PM   #12
Tomislav
Panty Schtuffer
 
Drives: 2008 E92 M3 Coupe
Join Date: Aug 2011
Location: Melbourne

Posts: 258
iTrader: (0)

Garage List
2008 E92 M3  [0.00]
This poses my next question then, why not just go with non-connecting pipes?
__________________
.: 2010 E71 X6M - stock, daily driver, towcar :.
.: 2008 E92 M3 - 6MT, Carbon Roof, Eibach Springs, Megan Axle Back exhaust :.
.: 1997 E36 323i Frankenstein - too much to list, track whore, stripped, caged, MoTeC, S85B50 :.
Tomislav is offline   Australia
0
Reply With Quote
      04-08-2012, 09:08 AM   #13
m3an
Banned
 
m3an's Avatar
 
Drives: M3
Join Date: Oct 2010
Location: South Florida

Posts: 1,611
iTrader: (2)

Quote:
Originally Posted by Tomislav View Post
This poses my next question then, why not just go with non-connecting pipes?
it won't make as much power and will most def be louder
m3an is offline  
0
Reply With Quote
      05-12-2012, 11:55 AM   #14
Raptor251
ESS Dreaming
 
Raptor251's Avatar
 
Drives: 2011.5 e92 m3/Ford Raptor 6.2
Join Date: Jan 2011
Location: San Diego

Posts: 870
iTrader: (1)

Just wanted to give a little update to this thread. I've been really curious as to why Akra has both a H/X pipes and seeing as how they make one of the best systems out there I figured they were on to something. I decided what the hell, since I've already cut up my RPI x pipe to add resonators and H pipe cant hurt! All I can say is WOW! The car sounds totally different, it has a much deeper tone and the intake noise is insane. The car was also a little raspy from 3-4k before and now the sound is so clean! I need to do a dyno asap! Sorry for the bad pics. You can see where I added the H in the second pic just behind the tranny
Attached Images
  
Raptor251 is offline   United_States
0
Reply With Quote
      05-12-2012, 01:16 PM   #15
Keik E92 M3
Banned
 
Drives: BMW M3 DCT
Join Date: Jan 2010
Location: SoCal

Posts: 1,349
iTrader: (6)

Garage List
2009 BMW  [4.50]
2011 BMW 335i  [3.40]
amazing!
Keik E92 M3 is offline   United_States
0
Reply With Quote
      05-12-2012, 02:51 PM   #16
E90///M3`
Major General
 
Drives: 2008 E90M3
Join Date: Jan 2009
Location: Daly City -4- Work///Camarillo is Home

Posts: 5,278
iTrader: (3)

Garage List
2008 BMW E90 M3  [3.80]
i see the X... i don't see the H?

it can't be in the second pic, cause the second pic only looks like a bar connecting the catalytic convertors. i thought an h-pipe actually had a hollow bar connecting the two pipes.
__________________
- Jason P
:Have: 08 E90M3, Varis VRS Front Lip, LS3, ESS Supercharger, Arqray Exhaust, Neez Wheels
:Want: VRS Carbon GT Wing & Cooling Bonnet, LCI Taillights
:Videos: EnvyRidesTV, GPR 1, GPR 2, GPR 3, ///MFEST
E90///M3` is offline   Philippines
0
Reply With Quote
      05-12-2012, 03:44 PM   #17
m3an
Banned
 
m3an's Avatar
 
Drives: M3
Join Date: Oct 2010
Location: South Florida

Posts: 1,611
iTrader: (2)

Quote:
Originally Posted by E90///M3` View Post
i see the X... i don't see the H?

it can't be in the second pic, cause the second pic only looks like a bar connecting the catalytic convertors. i thought an h-pipe actually had a hollow bar connecting the two pipes.

look at the polished piece to the right
m3an is offline  
0
Reply With Quote
      05-12-2012, 10:00 PM   #18
Raptor251
ESS Dreaming
 
Raptor251's Avatar
 
Drives: 2011.5 e92 m3/Ford Raptor 6.2
Join Date: Jan 2011
Location: San Diego

Posts: 870
iTrader: (1)

Quote:
Originally Posted by E90///M3` View Post
i see the X... i don't see the H?

it can't be in the second pic, cause the second pic only looks like a bar connecting the catalytic convertors. i thought an h-pipe actually had a hollow bar connecting the two pipes.
The H pipe is the new shiny piece welded in right before the resonators. (Those are resonators NOT cats). I bent and notched a piece of 2.5" stainless and then marked where the down pipes needed to be opened up to allow exhaust flow. I used the plasma cutter to open up the down pipes and cleaned up the opening with the air sander and a flap wheel. The piece of stainless was then fit back in and I mig welded it to match the rest of RPI's welds. Again sorry for the nasty pic. On another note I drove the car around all day and words cant describe the amazing difference in sound quality!! Oh and I also added that piece of 1/4 flat stock to the resonators to try and cut down on vibration noise and its helped! The factory clamps on the down pipes were removed from my OEM exhaust and fitted to the RPI system as their POS tabs snapped off a long time ago. Between the new tranny down pipe clamps, plate on the resonators for stiffness and the H pipe this thing sounds amazing. I think my favorite part about this car is how easy it is to work on!

Last edited by Raptor251; 05-13-2012 at 12:24 AM.
Raptor251 is offline   United_States
0
Reply With Quote
      05-13-2012, 04:59 AM   #19
E90///M3`
Major General
 
Drives: 2008 E90M3
Join Date: Jan 2009
Location: Daly City -4- Work///Camarillo is Home

Posts: 5,278
iTrader: (3)

Garage List
2008 BMW E90 M3  [3.80]
Quote:
Originally Posted by talontid View Post
look at the polished piece to the right
oooohhhh hahaha... damn i'm blind.
__________________
- Jason P
:Have: 08 E90M3, Varis VRS Front Lip, LS3, ESS Supercharger, Arqray Exhaust, Neez Wheels
:Want: VRS Carbon GT Wing & Cooling Bonnet, LCI Taillights
:Videos: EnvyRidesTV, GPR 1, GPR 2, GPR 3, ///MFEST
E90///M3` is offline   Philippines
0
Reply With Quote
      05-14-2012, 10:41 PM   #20
Raptor251
ESS Dreaming
 
Raptor251's Avatar
 
Drives: 2011.5 e92 m3/Ford Raptor 6.2
Join Date: Jan 2011
Location: San Diego

Posts: 870
iTrader: (1)

bump for some thoughts from the experts!
Raptor251 is offline   United_States
0
Reply With Quote
      05-14-2012, 11:17 PM   #21
Singletrack
4th down; 4th quarter? Renegade.
 
Singletrack's Avatar
 
Drives: 09 SSII E92 M3; 12 AW X5d
Join Date: Aug 2008
Location: Pittsburgh, PA

Posts: 3,791
iTrader: (3)

Quote:
Originally Posted by Raptor251 View Post
bump for some thoughts from the experts!
H-pipe on the Akra is located strategically.

Here is a thread in which Sal @ Evolve talks about the H-pipe on their former exhaust:

http://www.m3post.com/forums/showthread.php?t=384925
Singletrack is offline   United_States
0
Reply With Quote
      05-14-2012, 11:26 PM   #22
Raptor251
ESS Dreaming
 
Raptor251's Avatar
 
Drives: 2011.5 e92 m3/Ford Raptor 6.2
Join Date: Jan 2011
Location: San Diego

Posts: 870
iTrader: (1)

Thats an interesting thread, I would be curious to hear what Sal has to say about this almost two years later!
Raptor251 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 12:33 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