Hey guys I'm new to the forum and just got my first z3, 2.8 so I plan this too.
Just wanted to chip in and say you will massively benefit from a remap after doing this. I did it on my e36 328 Coupe, got it remapped a few months after the mod, and the difference was again a big step up from the hardware swap. It made 229bhp on the rolling road and I can't remember the figures but felt a lot more tourqey. The ecu needs to be reprogrammed to most effectively use all the extra airflow. If you can find a tuner that does bmws they should be familiar with the mod and know what to do. It's a fantastic mod and the remap really takes the m52 up to the next level. Cheers, Sam.
Great write up @Oldguysrule do it
a similar bhp, but a good few kg lighter.