The misinformation in this thread makes my head hurt. Nitrous is perfectly safe for your car, it's like any other sort of forced induction, it needs tuning.

The "shot" rating is generally referring to a horsepower increase. 50 shot will you give you about 50HP, 100 shot 100HP, etc. Personally, I would not do more than a 40%-50% increase in power with stock internals or a stock transmission as the integrity of these components will be compromised.