Quote:
| Originally Posted by DustenT The stock BMW header is very well designed. I am not an expert on this issue, but I'm going to assume that BMW did their homework on our factory headers. There are few way to gain hp via an economical 4 cylinder, free flowing exhaust is one. I doubt the hp=$ ratio is worth it. |
stock is a 4-2-1 and is a 2 piece IIRC.
This would be better atleast for flow.