i know very little about the boosting world (i see every people every now and then talking about [ct-26, ct-20b, ct-27 t3, t4, etc] turbo's and i just get lost) and i wanted to know how to tell turbos apart from each other, either by their model # (i.e. - ct-26??) or how to tell them apart visually? what makes some turbo's better than others? how many turbo's are out there? are they all interchangable (custom?)?