HEEEEELLLLLLLLLPPPPPPPPP!!!!!!

Hi everyone! :D Sorry for the misleading subject title, but I wanted to get your attention.

So basically I am completely torn apart on whether to do a Rear Muffler/Silencer/Back box (These are the same thing right? :? ) delete on my 03 M54 3.0i Z4. For those of you that don't know what this is, it basically involves removing the rear muffler/silencer from your exhaust and replacing it with some straight exit pipes to the rear of your bumper.

I have searched around on the forum and not that many people have done it to their M54 3.0i models. I have also searched on Youtube and there doesn't seem to be any videos of the M54 3.0i Z4 with the back box delete, unless I have missed them? :(

There are a few videos of the 3.0Si models on this forum though but they have the N52 engine.

Basically, what I want is a louder exhaust with some decent POPS BANGS AND CRACKLES! :P

I REPEAT, I WANT AN EXHAUST THAT GIVES GOOD POPS BANGS AND CRACKLES!!! :evil:

I'm not after a stupidly loud ricer fart can exhaust, just a more throaty burble :D

I have been reading other posts on this forum on people doing this mod and the owners seem to be happy with the noise but they have the 3.0si version. Is it only the 3.0si that will give off these reportedly loud bangs and pops?

The second option I was thinking was to remove the 2 catalytic converters on the underside of the car (NOT the manifold ones) AND the rear muffler to get those pops and bangs.

IF ANYONE HAS DONE THIS ON THEIR 3.0I M54 COULD THEY PLEASE POST UP SOME PICTURES OR A VIDEO WHICH WILL BE EVEN BETTER!

Much appreciated!!! :thumbsup:
 
BeetleGav has had this done on his m54. It sounds great but on a recent rolling road day, he was quite down on power. Unsure if it's related to the removal (not delete, it isn't a computer) of the backbox, but I still feel that It's a mod that could result in poor performance.
 
Aeroadster said:
I have searched around on the forum and not that many people have done it to their M54 3.0i models. I have also searched on Youtube and there doesn't seem to be any videos of the M54 3.0i Z4 with the back box delete, unless I have missed them? :(
I think you've missed them:

https://www.youtube.com/watch?v=BWk9rJ4noGk

https://www.youtube.com/watch?v=sp77HnOEvrU

https://www.youtube.com/watch?v=hYlAilJFd8U

https://www.youtube.com/watch?v=JeiScpPeTxg

2.5i sounds about the same as the 3.0i as it is almost the same engine (3.0i is stroked)

^ Somehow I don't think that removing the backbox will result in loss of power and that losses in power have other causes (not to mention that a rolling road doesn't give an exact reading of power. To see powerloss you have to do a before and after measurement with the same dyno and the same conditions (temp etc)
 
One of the Bristol zedders with an M54 had a straight pipe made and replaced the back box

For me ( sitting behind him and on runs out together) it sounded great, loud poppy etc. However he couldn't live with it ( drone ) and reverted back - it wasn't a daily driver for him either

I think these exhaust mods are great at tickover or whilst accelerating ( especially hard ) but once you sit at cruising speed for any length of time ( and especially if you do regular driving at steady speed ) then you would have to think seriously about what would be acceptable to you.

Done right it's reversible though so what's the risk?? Don't like it revert back?
 
Hi

My Z4 had a back box delete a few month back and the important thing here is the zed is not my daily driver. Spikey is 100% correct. Great sound on start up, great when pushing hard, but the drooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooaaaaaaaaaaaaaaaaaaaaaannnnnnnnnn is terrible. My delete is being deleted at present! I just cant live with it anymore.
 
As with the other commenters I also have a backbox delete that is now removed.

You do get a lovely sound but the drone was too much for 1-2 hour commutes.

I also have my backbox gutted which is better for commuting.

I have both on flanges though so I can swap out the backbox for certain events if I like.

It definately causes a power loss.
 
Disca said:
It definately causes a power loss.
you have a before&after dyno?


If you want a loud exhaust and keep the droan to a minimum you can always go for headers and mid muffler delete (to place cats on that spot).
That's what I did (I had to; I couldn't upgrade any further (TS2+) unless I removed the very very restricted exhaust manifolds)

That will give you a nice power increase, a loud exhaust&pops, cracks etc and keep de droan to a minimum revrange 1900-1950rpm.
With headers you get that typical inline 6 sound ('metallic' revving sound)
 
I don't have a dyno but I know it has an impact on the auto gearbox behavior, when out Oem backbox on again it was noticeably quicker in low rev range
 
Has anyone had a sports backbox custom fitted ? as everyone seems to either remove the box or leave it on.

I'm sure a custom exhaust company should be the way to go ? :poke:

This is what i'll be looking at next year
 
Hi everyone!

Thanks for all the tips and advise! :thumbsup:

So, there seems to be a varied response on this subject, some people reporting drone, power loss and some people loving the mod. With that being said, well....I'm still not sure if I should go ahead and give it a go...huhh :cry: .
I guess it's one of those things that you just need to give it a shot and see what its like and if I don't like it I can always go back to stock if necessary.

I have a second option that might seem more appropriate.

What do you guys think of removing the 2 catalytic converters from the underside of the car?(not the manifold cats). This should have no effect on the performance of the car, if any it should actually increase. And it should hopefully give me that POPPING BANGING sound that I am DYING for! :!: The car does POP and CRACKLE on some occasions when lifting of the accelerator but its just not loud enough and frequent as I want it to be :(

Hope to hear soon folks! :thumbsup:
 
I don't think you have cats under the car ;) :lol:

I presume you mean the mid muffler? That is something a lot of people do.
Your exhaust will become a little bit louder, (so also the pops/bangs), but not as near as in the video's. So certainly more bearable in every day use.
 
GuidoK , there was a member on this forum who said that he removed the 2 cats underneath. I'll try and find him...

I have also read on other posts that the car has 4 cats? lol
 
Ok so here it is:

http://www.z4-forum.com/forum/viewtopic.php?f=2&t=22122&start=15


http://www.z4-forum.com/forum/viewtopic.php?f=2&t=14291

Anybody know these guys?
 
http://2009.bmwfans.info/parts/catalog/E85/Roadster/Europe/Z4_3.0i-M54/RHD/N/2004/june/browse/exhaust_system/front_silencer/

Removing number 1 on the diagram a good idea?
 
Hi Aero, I removed the cats on mine , the ones under the zed, leaving the ones on the manifold untouched, however there wad a bit more noise but not what I wanted, so I then did the rear box bi-pass first using 17 mm pipe , not wot I wanted, so then I increased the pipe to 25 mm,
This coupled with removing the cats had given me the sound I wanted, pops and bangs on overrun, but more important to me a nice sporty tone especially giving it a few revs, I have no drone as I do eurotrips and that would have driven the boss lady crazy, a few mates have heard it and commented it now sounds like a sports car,
I personally couldnt live with the full back box delete as others have done.
Each to his own.
Also its gone thro two mot's without issue, although technically I think it against giude lines.
Moz
 
AlienZed said:
Hi Aero, I removed the cats on mine , the ones under the zed, leaving the ones on the manifold untouched, however there wad a bit more noise but not what I wanted, so I then did the rear box bi-pass first using 17 mm pipe , not wot I wanted, so then I increased the pipe to 25 mm,
This coupled with removing the cats had given me the sound I wanted, pops and bangs on overrun, but more important to me a nice sporty tone especially giving it a few revs, I have no drone as I do eurotrips and that would have driven the boss lady crazy, a few mates have heard it and commented it now sounds like a sports car,
I personally couldnt live with the full back box delete as others have done.
Each to his own.
Also its gone thro two mot's without issue, although technically I think it against giude lines.
Moz


Hi AlienZed, thanks for getting in touch! :thumbsup:

Do you have a video or any pictures you could show me?

Thanks!
 
Sorry bud not very gud on the new fangled tabs, (coz im an old fart ) dunno how how to post vids .All I'd say is try it , without spending loads , then whichever path u choose u can always revets it if its not wot u like, full backbox deletes r ok for sum but can get a bit waring on long journeys, deleting the cats only didnt do it for me , but using the 25mm bi pass pipes as well works for me, an more importantly for swimbo, lol.
Suppose the best solution is to find membrrs near u an av a listen c wot u think.
Im nr Stockport/ manchester.
M
 
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