So I want to know the options I have for adding power to my car, which is a Eurospec 1984 M635CSi. It doesn’t have a cat, already has K&N air filter system so there is nowhere to go there, as far as I know, heh. So I am thinking I have three options, replace the ECU, add a turbo, or add a supercharger. The thing is, I have no idea where to find any of those three things. I looked online for S38 ECU/Turbo/Supercharger and came up with pretty much nothing, though I did find stuff for the M535i, as it also has the S38 engine. Anyway, any help that can be provided would be awesome. Does anyone know where I can get any of these performance mods?