Wishfull thinking. What is the value of go fast parts.

Hi All

Been a while since I was here last. lots of water under the bridge generally but still running the 530i.

I was hoping I might get some advise regarding big bore thottle bodies and supersprint cat back exhaust for my baby.

The exhaust I understand will make only a marginal difference, mainly to the sound. Really need to find some low restriction cats.

Over size throttle. Will I notice an improvement and do I need to do any thing specail once fitted?