Imitations or Real Exhaust?????

can someone tell me if imitations are good or should i just buy the real brand exhaust?

and how much HP do i gain?

Well, really depends if you have a good local shop. If you do you can have one made exactly as you like. The name brand premade systems are a little more expensive. But you do get what you pay for, and you know that it is designed for your car. As far as HP gain, I really dont know. That really depends on your other mods, and what system you go with. I personally had a custom system made, and it cost me about the same as some of the nicer name brand systems. But I did get exactly what I wanted.