It's a really crappy intake and notoriously difficult to scale properly. I always beg people to take these things off and have me tune them with the stock intake on instead. As mentioned, your stock intake is good well past 350whp and no gain will be found below that range.
Pros: Sounds kewl mang.
Cons: Can hardly be tuned around to get a stable AFR, and running lean will damage your engine. May get less power than stock depending on how much work you put into keeping hot air off the filter. Flows no more than stock until into much higher flow ranges than your stock turbo can manage.
Don't type things you wouldn't dare say to someone's face.
Obligatory 'build thread