I'm just getting into the whole tuner scene so I'm trying to learn more about them but I have a few questions.
What is a must have controller for your car? Like fuel / air managment controller, ems, boost controller?(For a car w/ turbo and the whatnots).

What is the #V mean w/ intercoolers? Which is #?

I trying to find what I needed in search but there was so much stuff about the ems code's I couldn't find what I wanted.