who is running the 2 on the left on a ls1 and how does it sound and did it add any power??

 

i have that exhaust system on my machine and really like it. it has a deep, powerfull tone that isn't very obnoxious in commute mode, but really growls when i put my foot in it. i can't speak for any power gains as that the previous owner had installed it on the car. however, as that the exhaust flow path appears to be more straight with this design, i would be suprised if it made less power than any other slp design.