Sorry if this is a stupid question. Just a hobbyist here, playing about with winols and tweeking maps so far but just how does everybody know just enough fuel, boost etc. Is everyone just getting a "dyno tested" map and having a tweet themselves or how would someone learn about a new engines limitations?
Just having fun with it so far and interested in trying out on my own and friends cars without the KABOOM! Thanks in advance

In general most engines has been tested for various load limits to the breaking point and this is often discussed on the forums. Fuel mapping is preferably done with broadband lambda.