I know there are a few threads on the Flowmaster AT allready but I was wondering a few things on specifically the 2011 catback (part 817500). I know Flowmaster claims on average a 8hp and 12ft/lbs gain but I was wondering if anyone has any dynos of this? I was also wondering if you can feel any difference in throttle response or acceleration? Also, I heard back pressure is good for these cars. With the cat system only, would moving to a 3inch pipe be a bad thing? I don't plan on touching the headers or removing the cats.