Exhaust backpressure valve?

[moktar 7]

Hey all,

I recently replaced the rear 1/4 of the exhaust system. When doing this i noticed this..

I dont have much knowlege on this and would like to know more about it if any one can help.

From what i see is that it closes under vacume hence creating back pressure?

I think i could here it at certain times when driving the car but thought it was the Vanos kicking in?

Thanks for the help.

[moktar 7]

Opps i should have resized images... sorry

[Grant 4]

From what I understand, it opens at about 3,000rpm's. Its function is to make the exhaust quieter at low revs.

Cheers

Grant

[hybrid 1043]

my e46 had the same thing .. all gone now though

[moktar 7]

Yeah around 3,000rpm is where i heard the change in engine note, thats why i thouht vanos played a part in it.

oh well its gone now and sounds great. will post pics when i get a chance.

Thanks

[steve R 0]

i just pulled the vacuum hose off and plugged it, now its open all the time

[moktar 7]

Oh well its gone for good now. Mite attach a blow off valve to the vacume thinking of running 1 x exhaust pipe into a big BOV. I reckon itll be phat!

[hybrid 1043]

. . .

[steve R 0]

Oh well its gone for good now. Mite attach a blow off valve to the vacume thinking of running 1 x exhaust pipe into a big BOV. I reckon itll be phat!

[oscar90 0]

[Greg111 13]

Oh well its gone for good now. Mite attach a blow off valve to the vacume thinking of running 1 x exhaust pipe into a big BOV. I reckon itll be phat!

You're having a laugh aye????