Obviously b series is better but I want to start small and cheap so I was wondering if a d15 Is worth souping up idk how much it is to rebuild but I've seen some turbos for around 1k, or go b series. if I'm able to get 300-400 hp with the d15 then I'll stay with it if not then I'm going b series, if some one could f give me an idea of how much it would be to rebuild and turbo a d15 it would help alot