[BigCarrot]

n02 just adds more air (like a supercharger) ..... that allows you to add more fuel so more power can be made. If tuned correctly and a reasonable amount used then it is safe and will not harm the engine. Wear will be more....probably not noticeable with occasional use, but anytime you increase horsepower it is harder on the engine. More cylinder pressure = more pressure/wear on parts. That is the good (and bad) thing about nitrous....it is not there all the time.

Read this: http://www.holley.com/HiOctn/TechServ/TechInfo/NOSTech5.html

That's it in a nutshell!