Z4 Standard Exhaust De-baffle - Bafflerectomy!

EdButler

Senior member
 Sheffield
Hi All, after having a spare Z4 exhaust (im pretty sure the 2.2-3.0i use the same) lyring around for month, i finally got round to gutting it out. So here are my findings should anyone else wish to do the same!

Its not a very complex design at all, there are 3 chambers (see below), with the front a rear most having fibreglass wadding. The upstream most pipe is the only one that passes through the wadding with perforations. The rear most chamer presumably just dampens out the sound as the flow of air is directed away from the exhaust tail pipes. All chambers are separates, but both walls are perforated. One quite surprising thing, was that the baffle walls were welded to the outer steel container. Therefore if you were to do this yourself, only make cuts to access the front and rear most chambers (unless you were like me, and went mad with the plasma cutter to gut most of the innards too!)

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And here is what you will find inside! :?
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Weight saving would only be around 2kg... Mostly negated by fitting some exhaust clamps to put it back together! :roll: When i get round to fitting this ill get some sound clips up... I had a look into removing the mini resonators and the collector/merger bend, but these both looked "Straight Through" and i hate too much rasp, so gave them a miss.... for now! :P

Hope this helps/inspires someone :)
 
Thanks for posting. It will be good to compare your findings with those of Mr Whippy. Might be able to see model/year variations in design. Do you know the production date and model of the exhaust (car)?
 
Incompatible said:
Thanks for posting. It will be good to compare your findings with those of Mr Whippy. Might be able to see model/year variations in design. Do you know the production date and model of the exhaust (car)?

Yes mate, its a 2005 3.0 system, but looking at realOEM, all the Z4 6cyl engines use the same 2x50mm pipes. This could be the same for the Facelift Si engines also.

Oh yeah forgot about the haircut stage, maybe i could part it out and sell it on as hair extensions?! :lol:
 
Any news on the outcome of this?

I'm interested in getting a little more sound without great cost. (I have already done sound generator foam reduction).
 
A US member of another forum did it too and reported no difference in volume at all... :idunno:
 
mintstuff said:
Any news on the outcome of this?

I'm interested in getting a little more sound without great cost. (I have already done sound generator foam reduction).

You could get an exhaust place to cut out your middle silencers/resonators and replace them with straight sections. This would leave your backbox intact, and would be easily reversible. I'd imagine you'd get abit more noise, cheap too!
 
I've always wondered what was inside an exhaust backbox, guess this is where how hairdressers get rid of all their cuttings! That's fibreglass wadding?
 
fraserbottomley said:
mintstuff said:
Any news on the outcome of this?

I'm interested in getting a little more sound without great cost. (I have already done sound generator foam reduction).

You could get an exhaust place to cut out your middle silencers/resonators and replace them with straight sections. This would leave your backbox intact, and would be easily reversible. I'd imagine you'd get abit more noise, cheap too!

Thanks fraserbottomley, I'll look into that...
 
:thumbsup:

Here's a video of a 325i with the resonator deleted...

http://www.youtube.com/watch?v=g_Ak91YeRLc&feature=related

Not quite a Z4 but you get the picture.
 
Sorry i've been exceptionally lazy regarding the car lately, ill be just taking it to an exhaust shop soon and getting the thing chopped off!
 
Hi folks,

I want to resurrect this thread as I'm thinking of having a Bafflerectory at my local Indy next week.

Can anyone tell me the increase in volume?

At my last track day my 3.0i standard exhaust was measured at a measly 86db. Most tracks have a noise limit of around 95-105db. So whilst i don't think this mod would get near either of those numbers id be keen to know from those that have done this what increase in db they got.

Thanks

Pat
 
I don't think it will be much louder out the car, maybe more drone in the car.

If you create a more direct route for th pipes you'd get a few more db.
Guess someone has to measure it for you.
But why you asking?

Or better still what are you trying to get at?
 
Hi ba3bas,

I'm trying to get more sound out of the car without having to buy a new exhaust system. I don't want anything boy racer'ish just so it can be heard. lol I've done the sound gen mod, so in car it's furious but having done a couple of track days, when I come past the camera on the main straights the airflow over the car makes more noise than the exhaust. :rofl:

I've seen he bypass pipe mod but people said that it didn't make much difference so thought I'd give this a run.
 
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