I have a back-box with short pipes which are then U Bolted to center vibration damper box which has long rear pipes welded to box, front pipes from the damper are short then flange- clamped to long down pipes from manifold.
Sorry about spooky description, but none of this system corresponds with the drawings from BMW for my vehicle - I should have long pipes from manifold to center damper, short pipes both ends of the center damper - the rear should be: silencer then long pipes to the center damper.
Can't find anything to replace my center unit, they all have the wrong pipe arrangement to fit what I have - is it time for an entire new system - gulp - I need a mortgage!
Paul


