Question about exhaust sound level

[sumotan]

Hi Gents,
Hi guys been curious about this. My 28i on start with a growl but after something like 40 sec it quiets down.
Originaly I thought it was the flap in the rear muffler is closed but when I peak it remains fully open.
So where or what is it that quiets the exhaust if the flap remains fully open ?

Thanks Gents

 

[Smartbear]

Hi Gents,
Hi guys been curious about this. My 28i on start with a growl but after something like 40 sec it quiets down.
Originaly I thought it was the flap in the rear muffler is closed but when I peak it remains fully open.
So where or what is it that quiets the exhaust if the flap remains fully open ?

Thanks Gents

They’re noisy on startup due to the vacuum pump blasting air through the cat to lower emissions, when that stops the noise subsides.
Rob

 

[sumotan]

Aaah many thanks again Smartbear.
I've now got Catless downpipe & it sounds really good when its noisy lol there after I loose that growl.

 

[Smartbear]

Aaah many thanks again Smartbear.
I've now got Catless downpipe & it sounds really good when its noisy lol there after I loose that growl.

You can disconnect the exhaust valve for a little more sound
Rob

 

[sumotan]

Thanks again Rob

 

[ajguk]

Here's one in a similar vein - why does my N52 sound quieter when the e-brake is on if I blip the throttle? I don't sit revving the thing but just noticed and thought it was odd. If I'm right there's no valve in the exhaust (no golf-tee mod on the 30i).