Turbo help

[GP123]

I have one here, but i cant get it to go on, dont think its the right one for it. But can you see what im saying here mate, if it "was on" would it need to have the wee flap on the inside open or shut? Could i not still do the same effect without putting it on? because is the MBC not controlling what boost im getting then with a turn of the knob?

Sorry if this isnt really making sense, but gotta learn sometime. lol.

**edit..