With the E90 generation, the 325 / 328 / 330 all use the same N52 engines. The power difference comes from different ECU tuning as well as some minor hardware differences. Grassroots Motorsports actually has a 328 project on hand where they are doing precisely the needed upgrades to get the car back to 330 power levels:

https://grassrootsmotorsports.com/pr...o-our-e90-bmw/

The car looks clean and the price is attractive. But I have been completely spoiled by Japanese reliability, so I wouldn't dare to venture into something like this even when it looks like a good deal.

There are 3IMs that come up on facebook marketplace here and there. I've been tempted to get more power, but adding more parts that can fail on the bimmer seems like tempting the BMW gods to punish me.

Did you add more power on the 1er?