found out something interesting about the 1M exhaust...

[Dackelone]

Hey Guys,

I was talking to a German friend of mine who owns a 1M. He had changed out his exhaust system and sold his OE system. So he sold it. The guy who bought his mid pipes with cats - cut open the rear resonator in order to quell the "drone" that everyone hates. When he cut open the resonator at the end of the mid pipe... he found out the resonator dampner was DUMMY! Inside the pipe, was a solid pipe and passed thru the "resonator"!


So... this might be of help to someone wanting to rid their car of the drone. It should be noted that some 1M owners have insulated the area around the BlueTooth box under the trunk carpet where it meets the rear fold down seat area. You could use some DynaMat to try it as a fix.

But I think the news that the OE mid pipe is a "dummy" is quite interesting!

the resonator at the end of the mid pipe...




UPDATE...

I think I found a pic(s) of the factory 1M mid pipe resonator cut open. Like my German buddy told me... he sold his OE 1M mid pipe to a guy wanting a louder exhaust... so he cut open the resonator and was going to make a "straight pipe". But to his surprise... THAT is exactly what BMW had already done! So now we know why the stock exhaust drones a little bit!


Here are the pics I found on the web...

[Derek8819]

May help explain why the N55 mids quiet the drone as well since it has an actual resonator.

[MDORPHN]

Very interesting, indeed. Begs the question as to why BMW would "fake" a resonator.

Neil

[katsooba]

did he take any pictures of this?
sound intriguing
im about to modify my N55 midpipes to a Y pipe magnaflow,
if you say the mid-muffler is a dummy, than why would i do what i planed?
and why does the BMW PE has a Y pipe in their kit, if the mid-muffler is a dummy?

or is it a different story for the n55 midpipes?

[Dackelone]

Originally Posted by katsooba

did he take any pictures of this?
sound intriguing
im about to modify my N55 midpipes to a Y pipe magnaflow,
if you say the mid-muffler is a dummy, than why would i do what i planed?
and why does the BMW PE has a Y pipe in their kit, if the mid-muffler is a dummy?

or is it a different story for the n55 midpipes?

No. You have things mixed up.

On a 1M, the resonator just before the mid pipe goes into a "Y" is a fake(dummy) resonator.

The 135i does indeed have a real resonator, not a fake one. BMW's PE(Performance Exhaust) kit includes a Y-pipe to delete the 135i (functioning) resonator.

No, my friend did not take any pictures. But he did say he now knows why his new exhaust isn't as loud as he thought it would be.

[EINSER M]

the plot thickens! lol

[katsooba]

now its clearer to me thanks again Dack!

guess im going through with my Y midpipe
awesome!

[ozinaldo]

BMW decison makers (accountants I mean not the M division engineers) really didn't care too much about the 1M, was like a bone they threw to some old school enthusiasts and to passionate people in their own M department in order to pass time before more lucrative models could be made ready (M135i, F10 M5, next M3 etc.). It is despite their indifference or thanks to their lack of interest in an intriguing way this car came out so good and surprised lots of people, for sure those who didn't have any trust in this project in Munich more than the others.

Why I say this, because from the fake rear gills to planned but failed real opening of the side gills or a real CSL type trunk or a few more areas covered in alcantara inside, there is along list of "price cut" about the 1M, like there was an invisible "hold on" button someone kept on pressing during pre-production phases. Engineers got away with more important things though; like real hp, tq and performance of the car Thanks God missing things are nothing really significant, all minor details that we keep on fixing and modding. I came to an understanding that decison makers take such bad decisions in general maybe it was a chance for us to actually not have their interest focused on such an unimportant little car, the 1M

Other than down pipes there is not even a single piece worth keeping on our cars, the only obligatory mod in my opinion is the exhaust. OK, maybe the charge pipe too but one can always choose to wait till it blows or warranty expires.

[///1M]

Originally Posted by Dackelone

No. You have things mixed up.

On a 1M, the resonator just before the mid pipe goes into a "Y" is a fake(dummy) resonator.

The 135i does indeed have a real resonator, not a fake one. BMW's PE(Performance Exhaust) kit includes a Y-pipe to delete the 135i (functioning) resonator.

No, my friend did not take any pictures. But he did say he now knows why his new exhaust isn't as loud as he thought it would be.

So there may be two sources of drone, is that correct?

1.) the midpipe has a dummy resonator, and

2.) the section that is immediately upstream of the midpipe has a dummy resonator?

Thanks!

[Dackelone]

Originally Posted by ///1M

So there may be two sources of drone, is that correct?

1.) the midpipe has a dummy resonator, and

2.) the section that is immediately upstream of the midpipe has a dummy resonator?

Thanks!

No. I am talking about the resonator on the factory 1M mid pipe. While it looks real... when you cut it open... the pipe inside of it, goes straight thru the resonator (can) box.



Normally for the resonator to work... this pipe would have a bunch of holes drilled into it to the resonator packed with fiber and steel wool would quiet the sound. This pipe just goes straight thru on a 1M. When the "guy" cut his resonator open.... it just went straight thru - no holes or nothing.

For visuals... here is a factory N55 mid pipe (no cats - but still has the resonator just before the Y pipe) vs the factory N54 mid pipe with cars. The 1M uses a very similar mid pipe (to the N54) just that the 1M has the straight thru pipe inside of the resonator.




Dack

[///1M]

Thanks Dack!

[providence]

So let me get this straight: if I were to swap the resonators between the n54 and N55 I could end up with a straight pipe with even less sound insulation and sound dampening?

[Smiley1175]

Dack this is very interesting.

Recently I picked up a set of N54 mid pipes which had the cats gutted (ie cut open, cleaned out and welded back).

I felt like the car went backwards in performance. It made no real difference but it just didn't feel or sound like an improvement.
I can see now that the resonator would have been active on this n54 midpipe compared with the oem 1M. I removed one restriction but added in another.
It also didn't really do much to the drone, so I personally wouldn't recommend n55 mids for the 1M.
I'll be installing Berk mids in a week and see what that does.

Thanks again for the info, you're always a wealth of information.

[Ian///M]

Originally Posted by Smiley1175

Dack this is very interesting.

Recently I picked up a set of N54 mid pipes which had the cats gutted (ie cut open, cleaned out and welded back).

I felt like the car went backwards in performance. It made no real difference but it just didn't feel or sound like an improvement.
I can see now that the resonator would have been active on this n54 midpipe compared with the oem 1M. I removed one restriction but added in another.
It also didn't really do much to the drone, so I personally wouldn't recommend n55 mids for the 1M.
I'll be installing Berk mids in a week and see what that does.

Thanks again for the info, you're always a wealth of information.

+1 to Berks / MadDads. N55 mids are a waste

[Dackelone]

Originally Posted by providence

So let me get this straight: if I were to swap the resonators between the n54 and N55 I could end up with a straight pipe with even less sound insulation and sound dampening?

Noop. The N54 and N55 mid pipes have the same rear(box) resonator. The N55 mid pipe does not have the secondary cats(which the N54 and 1M have) - which restrict flow somewhat.

The 1M has secondary cats in the mid pipe(just like a N54) but the resonator box is a fake. So that is why its more raspy. ie:drone. because the 1M's resonator on the mid pipe is fake. The pipe just continues thru the resonator/box.

[Artemis]

Here's a picture of the hidden storage area under the trunk felt pad behind the battery compartment.

Forum fellow Derek8819 pointed out that, on former 1ers, this space was used for installation of add-on modules (such as SATNAV and Bluetooth). In the 1M these devices, if chosen as option, are installed in the head unit.

It is suspected that this empty cavity could be related to the 1M drone:
http://www.1addicts.com/forums/showt...php?p=12850245

[Derek8819]

I'd still like to see pics because the N55 mids definitely add to the performance.

[1911A145]

Lol...

The resonator is real...

It is a straight through, perforated resonator. When you look through it, it looks like a straight pipe, but add some light and you will see it is perforated and does indeed muffle the exhaust as its purpose...

[HERR FSTIR]

I have MadDads installed and my OEM mid pipe is sitting on the shelf. So I went out into the garage and took a picture of inside the stock mid pipe resonator. I don't see any perforations. Am I missing something?

[135IS]

Originally Posted by HERR FSTIR

I have MadDads installed and my OEM mid pipe is sitting on the shelf. So I went out into the garage and took a picture of inside the stock mid pipe resonator. I don't see any perforations. Am I missing something?

im pretty sure they are saying thats its hollow just like u posted hence the "dummy" part

[Derek8819]

Does the 1M mid pipe have a different part number than the regular N54s?

[0110001]

Does any know of anybody completely changing the mid-pipes on the N54? I had a wild thought and was wondering if someone might have done this already... Being that I already have the Berk Muffler Delete Pipe installed, converting the mid-pipe into one 3.5" exhaust. To accomplish this I would have a "Y" pipe installed immediately after the down pipes collecting into a 3.5" exhaust. it seems like this would be a bit more manageable underneath the vehicle and remove all of the exhaust restrictions after the DP's.