moktar 7 Report post Posted May 17, 2008 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. Quote Share this post Link to post Share on other sites
moktar 7 Report post Posted May 17, 2008 Opps i should have resized images... sorry Quote Share this post Link to post Share on other sites
Grant 4 Report post Posted May 17, 2008 From what I understand, it opens at about 3,000rpm's. Its function is to make the exhaust quieter at low revs. Cheers Grant Quote Share this post Link to post Share on other sites
hybrid 1043 Report post Posted May 17, 2008 my e46 had the same thing .. all gone now though Quote Share this post Link to post Share on other sites
moktar 7 Report post Posted May 17, 2008 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 Quote Share this post Link to post Share on other sites
steve R 0 Report post Posted May 18, 2008 i just pulled the vacuum hose off and plugged it, now its open all the time Quote Share this post Link to post Share on other sites
moktar 7 Report post Posted May 18, 2008 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! Quote Share this post Link to post Share on other sites
hybrid 1043 Report post Posted May 18, 2008 . . . Quote Share this post Link to post Share on other sites
steve R 0 Report post Posted May 18, 2008 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! Quote Share this post Link to post Share on other sites
Greg111 13 Report post Posted May 20, 2008 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???? Quote Share this post Link to post Share on other sites