What is this thing on a 3.0 l manifold

[G-A-R-Y]

 

[synthedup]

Looks like its the sound generator, if you remove the foam from inside the pipe if increases the intake noise in the cabin.

 

[G-A-R-Y]

It does have a lot of noise, I thought the air filter was missing. Where is this foam exactly. I'm off to the dealers for the oil filter housing gasket right now.

 

[Swiftly]

There are 2 different sizes of foam, a large one and a smaller one. A piece of foam goes in each end of part 6

http://www.realoem.com/bmw/enUS/showparts?id=BT52-EUR-11-2004-E85-BMW-Z4_30i&diagId=13_0999

[youtube]UVijH3_C1ZY[/youtube]

 

[G-A-R-Y]

Thanks, I would be putting the foam back in but Son wants to take it out.

 

[markeg]

I was going to say "dirt"..... :wink:

 

[PerryGunn]

I was going to say "dirt"..... :wink:

wned:

 

[G-A-R-Y]

I hope people realise that by taking the sponge out of this pipe/tube they are affecting performance and making the car slower, it might sound louder and give the illusion of speed but quite the opposite.

 

[ben g]

I hope people realise that by taking the sponge out of this pipe/tube they are affecting performance and making the car slower, it might sound louder and give the illusion of speed but quite the opposite.

Are you trolling? It's purely 'cosmetic' in that it doesn't affect performance whatsoever.

All it does is pipe the intake sound into the cabin. By removing the foam, the sound is louder. Simple.

You must be on drugs if you think removing a bit of foam from a 'sound generator' affects performance :lol:

 

[G-A-R-Y]

I may be mistaken but I'll explain how I see it.
All the air entering the engine goes through the MAF, which in turn adjusts the fueling in relation to mixture, by removing the foam and allowing air to enter the manifold means less air is going through the MAF, in turn the engine gets less fuel which means less performance.

 

[Smartbear]

Hi, your understanding of this is flawed-the sound generator is hermetically sealed from the inlet manifold, the sound carries through by vibrating a "drum" type membrane which transfers the sound across into the sound generator pipe & to the cabin.
I ran mine with it completely disconnected for a while & there were no air leaks
Rob

 

[mr.tourette]

all the air travels into the manifold... the only thing going down the piping is acoustic sound waves

 

[sars]

I may be mistaken but I'll explain how I see it.
All the air entering the engine goes through the MAF, which in turn adjusts the fueling in relation to mixture, by removing the foam and allowing air to enter the manifold means less air is going through the MAF, in turn the engine gets less fuel which means less performance.

I've never sat down and thought of the implications of this mod, but I'm pretty sure that they are there for a reason, I for one don't include an item in a design that serves no purpose. As I don't design engines for BMW a can't say how significant it is but the foam will both absorb sound and offer some resistance to any air flow

 

[Smartbear]

I may be mistaken but I'll explain how I see it.
All the air entering the engine goes through the MAF, which in turn adjusts the fueling in relation to mixture, by removing the foam and allowing air to enter the manifold means less air is going through the MAF, in turn the engine gets less fuel which means less performance.

I've never sat down and thought of the implications of this mod, but I'm pretty sure that they are there for a reason, I for one don't include an item in a design that serves no purpose. As I don't design engines for BMW a can't say how significant it is but the foam will both absorb sound and offer some resistance to any air flow

That's the thing sars, there is no air flow-only the sound waves travel through the pipe & it's not directly connected to the inlet manifold.
I removed mine completely and the engine ran exactly the same
Rob

 

[sars]

That's the thing sars, there is no air flow-only the sound waves travel through the pipe & it's not directly connected to the inlet manifold.
I removed mine completely and the engine ran exactly the same
Rob

So why put them there in the first place? I do not imply that I know, it's just that this cat's curious has anyone put their car on a dynamometer before and after to see if there's a difference?

 

[Smartbear]

That's the thing sars, there is no air flow-only the sound waves travel through the pipe & it's not directly connected to the inlet manifold.
I removed mine completely and the engine ran exactly the same
Rob

So why put them there in the first place? I do not imply that I know, it's just that this cat's curious has anyone put their car on a dynamometer before and after to see if there's a difference?

There wouldn't be any difference, trust me I know about these things
The foam is an easy way to suppress the sound waves travelling through the empty pipe, it's for aural pleasure only :wink:
Rob

 

[sars]

That's the thing sars, there is no air flow-only the sound waves travel through the pipe & it's not directly connected to the inlet manifold.
I removed mine completely and the engine ran exactly the same
Rob

So why put them there in the first place? I do not imply that I know, it's just that this cat's curious has anyone put their car on a dynamometer before and after to see if there's a difference?

There wouldn't be any difference, trust me I know about these things
The foam is an easy way to suppress the sound waves travelling through the empty pipe, it's for aural pleasure only :wink:
Rob

Well it could just be that during pre-production tests some exec said, mein got thatz a loud engine and the young bright engineer said itz zee zound generator I invented. Exec says make it quieter

excuse my German accent

 

[PerryGunn]

Well it could just be that during pre-production tests some exec said, mein got thatz a loud engine and the young bright engineer said itz zee zound generator I invented. Exec says make it quieter

excuse my German accent

I, for one, think it excellent - did you have to learn German as part of your engineering degree :wink:

 

[Smartbear]

So why put them there in the first place? I do not imply that I know, it's just that this cat's curious has anyone put their car on a dynamometer before and after to see if there's a difference?

There wouldn't be any difference, trust me I know about these things
The foam is an easy way to suppress the sound waves travelling through the empty pipe, it's for aural pleasure only :wink:
Rob

Well it could just be that during pre-production tests some exec said, mein got thatz a loud engine and the young bright engineer said itz zee zound generator I invented. Exec says make it quieter

excuse my German accent

That's easy for you to say

 

[sars]

Well it could just be that during pre-production tests some exec said, mein got thatz a loud engine and the young bright engineer said itz zee zound generator I invented. Exec says make it quieter

excuse my German accent

I, for one, think it excellent - did you have to learn German as part of your engineering degree :wink:

Why thanks Mr Gunn, I thought I was going to be real smart and took lessons in Japanese, I thought Geisha's looked pretty but didnt understand what they did