Injectors, Boost gauge, Tuning Program(hondata, crome, etc, dunno what car/motor you have). I would think thats all you would need for the bare basics with the turbo kit itself. Turbo Timer, Boost controller could be extras that prolly arent needed, just nice to have. Check my thread, I have a COMPLETE turbo kit for sale on there. No BS everything is there. Goodluck man. ^by the way the man posted before me knows what the deal is too.