I am trying to understand the OEM exhaust system on the E92 335i in the hope it helps me decide on an aftermarket one for my car.
I plan on catless DPs and will retain the secondary cats section. I am wondering whether to replace the centre section/muffler together with the rear section; or just the rear section. The aim is to achieve the best performance gain, understanding that I am retaining the secondaries.
The diagram below shows the factory system, as I understand it for the E92, which has 4 separate sections. Going left to right are the sections from the front to rear of the car.
Am I correct in saying that item # 1 is the balance pipe between the left and right side of the system? Seems to me the BMW PE system is also set up this way.
Is there any other balance pipe in the system, perhaps in the centre section as part of the muffler, # 2 in the diagram?
How important is it to have a balance pipe in the system?
Thanks and cheers,
Jon