Originally Posted by moocow
nothing yet. a couple of threads involve turbos. another thread is about the upsolute retune chip. but nothing significant yet. A lot of people feel that there is not a lot of HP left to tweak out of the e90 engine...
The mods on the 330i will most likely reduce reliability, increase engine noise etc. But the 325i will/should have some easy gains, since the engines are similar, that do not have any trade offs.