ive only heard of this on gran turismo so i dont know much about it. what is it? how much hp can it add? and how much$$$$? and what are the advantages and disadvantages? any help is appreciated

 

NA meaning Naturally Aspirated which means no turbo,super or NOS. An "N/A Build" would be any internal motor mods such as cams pistons rods and some work to the cylinder head. Check out howstuffworks.com to learn about engines and youll see what i mean. As far as the other questions, it all depends on what you do to your motor. They all cost different amounts and add different HP.