Hello guys, I am new to this forum, and although not new to BMW, the Z4 3.0 si is the first BMW that I actually own and will have the pleasure of tuning.
Since I am very concerned with engine longevity I try to avoid getting a chip without upgrading the cooling system. Sadly, I could not find a kit for the E86 Z4 3.0 si that contains a chip and a cooling system upgrade, so for now I will only concentrate on the easier bits.
So here goes my question. What exhaust system, sport/racing cat and sport/racing air filter can anyone recommend that would give a combined boost in power of at least 25-30bhp?
Thanks in advance to all who help
