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




 

Post Reply
 
Thread Tools Search this Thread
      04-26-2013, 11:26 AM   #1
Steph
New Member
Belgium
6
Rep
26
Posts

Drives: M3 Telesto CP MY18
Join Date: Apr 2008
Location: Belgium

iTrader: (0)

Akrapovic slip-on valve open vs. closed / N54 vs. N55 mid

I have an Akrapovic slip-on on my 1M but no remote control valve kit.
For those who have; are your outer tailpipes completely inactive, i.e. zero exhaust flow, when valve is closed?

In my case the installer told me that they partly opened blocking plate, and indeed the outer pipes do have exhaust gas flow, although not as much as inner pipes. I wonder if it's worth to buy the wireless kit in this case, now it's likely louder then valve fully closed but not as loud with valve fully open...?


Secondly, how does Akra slip-on wih N54 midpipe compare to Akra + N55? Anybody has any sound clips of both?


Thanks
Appreciate 0
      04-26-2013, 12:41 PM   #2
///1M
Captain
17
Rep
612
Posts

Drives: On a good day, AW 1M coupe
Join Date: Mar 2011
Location: between Indiana and the alley

iTrader: (0)

Can I infer that you're not that thrilled with the sound of just the Akra with stock midpipes?
Appreciate 0
      04-26-2013, 01:56 PM   #3
NjSant
Private
15
Rep
65
Posts

Drives: BMW
Join Date: Aug 2011
Location: USA

iTrader: (0)

Im interested to know how your installer partly opened the blocking plate but to answer your questions:

With the valve closed there is no exhaust flow through the outer tailpipes. With the valve closed it will be around stock decibel wise, maybe slight tonal differences. With the valve open it will sound beastly, especially if matched with a N55 midpipe or MadDad, with exhaust flow through all tail pipes.

Heres a video posted recently of the akra+N55 pipes.

Also, two great threads with everything and anything you need to know about how the wireless kit works.
http://www.1addicts.com/forums/showp...21&postcount=4
http://www.1addicts.com/forums/showp...0&postcount=12

Appreciate 0
      04-26-2013, 05:07 PM   #4
Steph
New Member
Belgium
6
Rep
26
Posts

Drives: M3 Telesto CP MY18
Join Date: Apr 2008
Location: Belgium

iTrader: (0)

Ok thanks, so I understand with wireless kit and valve closed there is NO flow through outer pipes. Well in my case there is surely exhaust flow through outer pipes, maybe about 1/4th of the inner pipes flow or so. But I don't have the wireless kit, so I guess it is louder as the wireless kit with valves closed but surely not as load as in the sound clips with valves fully open.

As to stock vs. N55 mid; Iíve read so much about it on this forum, but I never found any comparison of akra slip-on with stock vs. N55 mid. Would be interested to hear oneís experiences. I run N54ís and would possibly consider doing N55 if itís really worth it, on the other hand I donít want to get in trouble with authoritiesÖ
Appreciate 0
      04-26-2013, 06:09 PM   #5
flzrider
Captain
42
Rep
740
Posts

Drives: AW 1M
Join Date: Oct 2005
Location: Miami, FL

iTrader: (1)

Quote:
Originally Posted by Steph View Post
Ok thanks, so I understand with wireless kit and valve closed there is NO flow through outer pipes. Well in my case there is surely exhaust flow through outer pipes, maybe about 1/4th of the inner pipes flow or so. But I don't have the wireless kit, so I guess it is louder as the wireless kit with valves closed but surely not as load as in the sound clips with valves fully open.

As to stock vs. N55 mid; Iíve read so much about it on this forum, but I never found any comparison of akra slip-on with stock vs. N55 mid. Would be interested to hear oneís experiences. I run N54ís and would possibly consider doing N55 if itís really worth it, on the other hand I donít want to get in trouble with authoritiesÖ
I really don't think there will be any advantage (in terms of sound only) going to N55 midpipes. Dackel recently found that the N54 midpipes are not resonated, whereas the N55 midpipes are. So in all actuality, it may get quieter going to N55 mids.

For a point of reference, I have a stock (N54) mids on my 1M + Akra slip-on with no valve kit (always open) and I think it sounds great. I could probably go even a bit louder.
__________________
Appreciate 0
      04-26-2013, 07:13 PM   #6
RoadRunner///M
Major General
RoadRunner///M's Avatar
No_Country
296
Rep
6,523
Posts

Drives: 1M (Sold), M3 F80
Join Date: Mar 2011
Location: Sydney, Oz

iTrader: (0)

Get Maddad mids... Nothing better IMO
__________________
BMW F80 M3 DCT - Silverstone II - AA Mids, BM3 tune
Appreciate 0
      04-26-2013, 10:10 PM   #7
yemski
Lieutenant
yemski's Avatar
United_States
30
Rep
491
Posts

Drives: 2011 1M
Join Date: Oct 2006
Location: Bay Area

iTrader: (2)

Garage List
2011 1M Coupe  [0.00]
Quote:
Originally Posted by flzrider View Post
I really don't think there will be any advantage (in terms of sound only) going to N55 midpipes. Dackel recently found that the N54 midpipes are not resonated, whereas the N55 midpipes are. So in all actuality, it may get quieter going to N55 mids.

For a point of reference, I have a stock (N54) mids on my 1M + Akra slip-on with no valve kit (always open) and I think it sounds great. I could probably go even a bit louder.
One thing to note is that the N55 mids remove two cats.
Appreciate 0
      04-26-2013, 11:02 PM   #8
Artemis
Moderator
Artemis's Avatar
Belgium
10596
Rep
9,566
Posts

Drives: BMW M2 (MG 6MT)
Join Date: Jun 2011
Location: Belgium

iTrader: (0)

Quote:
Originally Posted by Steph View Post
In my case the installer told me that they partly opened blocking plate, and indeed the outer pipes do have exhaust gas flow, although not as much as inner pipes.
A permanently semi-muzzled Akra ? Man, that's some sort of aural chastity !

Except if mistaken, every Akra forum fellow over here either got the wireless kit (to zap at will between "open valve" and "closed valve" mode ) or got the blocking plate completely removed (permanent loudness) (http://www.1addicts.com/forums/showp...57&postcount=8). From what you say, I believe to understand that getting the wireless kit seems the right thing for you. In "closed valve" mode (no exhaust flow through the outer pipes) the Akra sound is actually quite similar to the stock OEM sound. Static noise level at 3750 rpm is the same (81 dB). In "open valve" mode (exhaust flow through the outer pipes too) it's, uh, pretty impressive.

Quote:
Originally Posted by flzrider View Post
I really don't think there will be any advantage (in terms of sound only) going to N55 midpipes. Dackel recently found that the N54 midpipes are not resonated, whereas the N55 midpipes are. So in all actuality, it may get quieter going to N55 mids.
The N55 midpipe will get you a slightly improved sound (+ a few extra hp) compared to the N54. No secondary cats (N55) = less exhaust flow restriction.
http://www.1addicts.com/forums/showp...0&postcount=27 (N55 midpipe)
http://www.1addicts.com/forums/showthread.php?t=797160 (N55 midpipe DIY installation process)

IMHO N55 + Akra = doing justice to the 1M.
__________________
///M is art Artemis
Appreciate 0
      04-27-2013, 01:44 AM   #9
1'M Blue
Major
Oman
208
Rep
1,009
Posts

Drives: 1M
Join Date: Nov 2011
Location: OM

iTrader: (0)

Get the Wireless kit .. open vs closed makes big differences .. so you can enjoy it and same time not cause noisy problems elsewhere ..
Appreciate 0
      04-27-2013, 03:19 AM   #10
Mpro
Enlisted Member
Mpro's Avatar
Belgium
5
Rep
45
Posts

Drives: AW 1M & other BMW's
Join Date: Oct 2011
Location: East-Flanders - Belgium

iTrader: (0)

Don't be afraid to get in trouble with the authorities if you switch to N55 mids.
This is an OEM part, I doubt there's 1 technician at the inspection who knows the difference between N54 and N55 mids.
By the way: You can always put the N54 mids back on if necessary.

I've heard both in combination with Akra Slip on and there is a difference in sound.
The removal of the secondary cats also gives you a few extra ponies.

Where are you exactly from in Belgium?
I have Akra slip on (with wirereless) + N55 mids.
We can always meet so you can hear it in real life and compare with your sound.
Appreciate 0
      04-27-2013, 04:38 AM   #11
Steph
New Member
Belgium
6
Rep
26
Posts

Drives: M3 Telesto CP MY18
Join Date: Apr 2008
Location: Belgium

iTrader: (0)

Quote:
Originally Posted by Mpro View Post
Don't be afraid to get in trouble with the authorities if you switch to N55 mids.
This is an OEM part, I doubt there's 1 technician at the inspection who knows the difference between N54 and N55 mids.
By the way: You can always put the N54 mids back on if necessary.

I've heard both in combination with Akra Slip on and there is a difference in sound.
The removal of the secondary cats also gives you a few extra ponies.

Where are you exactly from in Belgium?
I have Akra slip on (with wirereless) + N55 mids.
We can always meet so you can hear it in real life and compare with your sound.

I'm from region Sint-Niklaas, but spend quite some time in Gent during the week too. Would definitely be interested to hear difference valve open/closed vs. my setup in real life!
Appreciate 0
      04-27-2013, 04:39 AM   #12
Steph
New Member
Belgium
6
Rep
26
Posts

Drives: M3 Telesto CP MY18
Join Date: Apr 2008
Location: Belgium

iTrader: (0)

Quote:
Originally Posted by flzrider View Post
I really don't think there will be any advantage (in terms of sound only) going to N55 midpipes. Dackel recently found that the N54 midpipes are not resonated, whereas the N55 midpipes are. So in all actuality, it may get quieter going to N55 mids.
Interesting...could you explain a little more or point me to this post please? Thanks
Appreciate 0
      04-27-2013, 05:14 AM   #13
Zuzu
Major General
Zuzu's Avatar
Australia
227
Rep
7,440
Posts

Drives: LBB LCI M2
Join Date: Mar 2008
Location: Sydney Australia

iTrader: (0)

Quote:
Originally Posted by flzrider View Post
I really don't think there will be any advantage (in terms of sound only) going to N55 midpipes. Dackel recently found that the N54 midpipes are not resonated, whereas the N55 midpipes are. So in all actuality, it may get quieter going to N55 mids.

For a point of reference, I have a stock (N54) mids on my 1M + Akra slip-on with no valve kit (always open) and I think it sounds great. I could probably go even a bit louder.
Disagree completely...
There is deffinately without a doubt, an advantage in terms of sound, by switching to the N55 mids

Quote:
Originally Posted by yemski View Post
One thing to note is that the N55 mids remove two cats.
Exactly, and give you up to an extra 8 killer wasps of untapped oommphh..
Appreciate 0
      04-27-2013, 05:40 AM   #14
Mpro
Enlisted Member
Mpro's Avatar
Belgium
5
Rep
45
Posts

Drives: AW 1M & other BMW's
Join Date: Oct 2011
Location: East-Flanders - Belgium

iTrader: (0)

Quote:
Originally Posted by Steph View Post
I'm from region Sint-Niklaas, but spend quite some time in Gent during the week too. Would definitely be interested to hear difference valve open/closed vs. my setup in real life!
PM sent
Appreciate 0
      04-27-2013, 11:38 AM   #15
Artemis
Moderator
Artemis's Avatar
Belgium
10596
Rep
9,566
Posts

Drives: BMW M2 (MG 6MT)
Join Date: Jun 2011
Location: Belgium

iTrader: (0)

Quote:
Originally Posted by Mpro View Post
I have Akra slip on (with wireless) + N55 mids.
We can always meet so you can hear it in real life and compare with your sound.
Quote:
Originally Posted by Steph View Post
Would definitely be interested to hear difference valve open/closed vs. my setup in real life!
We're all in a perimeter of Ī 50 kms. No doubt that your order for a wireless kit and N55 midpipe will be the first thing in the morning after an eventual 'treffen' with the 1Ms of Mpro and me. Da geef goe pulle, zunne.

Quote:
Originally Posted by Zuzu View Post
Disagree completely...
There is definitely without a doubt, an advantage in terms of sound, by switching to the N55 mids
I think flzrider did a little 'Randy Pobst' with his N54/N55 statement.
__________________
///M is art Artemis
Appreciate 0
      04-27-2013, 02:20 PM   #16
flzrider
Captain
42
Rep
740
Posts

Drives: AW 1M
Join Date: Oct 2005
Location: Miami, FL

iTrader: (1)

Quote:
Originally Posted by Steph View Post
Interesting...could you explain a little more or point me to this post please? Thanks

http://www.1addicts.com/forums/showt...ight=Resonator

Last edited by flzrider; 04-29-2013 at 02:19 PM..
Appreciate 0
      04-27-2013, 06:24 PM   #17
Zuzu
Major General
Zuzu's Avatar
Australia
227
Rep
7,440
Posts

Drives: LBB LCI M2
Join Date: Mar 2008
Location: Sydney Australia

iTrader: (0)

Quote:
Originally Posted by Artemis View Post
I think flzrider did a little 'Randy Pobst' with his N54/N55 statement.


Quote:
Originally Posted by flzrider View Post
http://www.1addicts.com/forums/showthread.php?t=779462&highlight=Resonator
That thread is more to do with the "dreaded" 1M OEM drone, than sound reduction of not having a "true" resonator.
Appreciate 0
      04-28-2013, 08:57 AM   #18
sparoz
Brigadier General
sparoz's Avatar
Australia
146
Rep
4,849
Posts

Drives: VO 1///M; Macan Turbo
Join Date: Jun 2008
Location: Sunshine Coast

iTrader: (0)

I personally like the wireless kit, but I have the full evolution so I might not be the best to contribute here. I love the sound when the valve is closed for daily. Definitely not too much and sound very elegant, and what the stock car should have been. I only open the valve on track and when I am doing runs on B road.
__________________
Macan S Diesel - Carrera White
Macan Turbo - White
1///M - Valencia Orange
Appreciate 0
      04-29-2013, 02:28 PM   #19
flzrider
Captain
42
Rep
740
Posts

Drives: AW 1M
Join Date: Oct 2005
Location: Miami, FL

iTrader: (1)

Quote:
Originally Posted by Zuzu View Post
That thread is more to do with the "dreaded" 1M OEM drone, than sound reduction of not having a "true" resonator.
What I was trying to point out is that the 1M's N54 midpipes have cats, but no resonators, whereas the N55 midpipes have no cats, but does have a resonator. Cats, of course, restrict flow and resonators quiet down sound. So all other things remaining equal, it seems logical there will not be a major upgrade in terms of sound if one were to go from N54 to N55 midpipes on their 1M. If you have a video clip or objective data that proves otherwise, I'd love to see it as I wouldn't mind getting a small sound (and HP) bump on my current exhaust setup.
__________________
Appreciate 0
      04-29-2013, 02:55 PM   #20
ozinaldo
Brigadier General
ozinaldo's Avatar
Portugal
95
Rep
3,073
Posts

Drives: 1M
Join Date: Jan 2011
Location: Lisbon, Portugal

iTrader: (0)

Quote:
Originally Posted by flzrider View Post
What I was trying to point out is that the 1M's N54 midpipes have cats, but no resonators, whereas the N55 midpipes have no cats, but does have a resonator. Cats, of course, restrict flow and resonators quiet down sound. So all other things remaining equal, it seems logical there will not be a major upgrade in terms of sound if one were to go from N54 to N55 midpipes on their 1M. If you have a video clip or objective data that proves otherwise, I'd love to see it as I wouldn't mind getting a small sound (and HP) bump on my current exhaust setup.
Hp/Tq gains are undeniable though modest; BUT, because all those additional horses appear to be running upper in the rev where you need them most, makes this swap to N55 mids worthwhile. Plus, there is a noticeable gain in throttle response, some members like Advevo who made merely this swap and no other mods (simultaneously) in the past have posted precisely this gain; that especially on/off/on throttle response is better with N55 mids, probably more so with default mode and not the M button pressed. Again, there is undeniable easing of the stock drone problem and in some cases eliminating it all together. I enjoy all these effects every day and the price seems like a bargain when you take into consideration what you take back.

Now the sound: I agree with you that soundwise the difference is probably small for most unless they have very sensitive ears, especially smaller than wonderful Maddads which have a distinctive and aggressive sound. But this is why I always advice the N55 mids to people who will match them with DPs and/or a loud rear muffler because they sure have all the other benefits in full and it seems like a better idea for me to preserve the sound characteristics of whatever muffler you choose to go with rather than either diluting the sound of that muffler and also of the Maddads or other brand mid pipes to that effect.

On the other hand, if the goal is to maximize the sound with less drone without also installing an aftermarket muffler or a DP, then N55 are NOT the best solution since imho they are "silent achievers"
Appreciate 0
      11-28-2013, 07:19 AM   #21
3rdgear
Private
China
3
Rep
99
Posts

Drives: black 1m gt 535i
Join Date: Jul 2013
Location: shanghai

iTrader: (0)

So is the ak in red or white mode without the wireless kit
Appreciate 0
      11-28-2013, 07:24 AM   #22
3rdgear
Private
China
3
Rep
99
Posts

Drives: black 1m gt 535i
Join Date: Jul 2013
Location: shanghai

iTrader: (0)

So guys without the wireless, is the ak in red or white mode, have read many posting but still don't really get it, I see smoke out of all 4 pipes but there is hardly any sound when the car is stationary. So confused
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 03:32 AM.




1addicts
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