Even if it is a borla manifold and its steel, i got ceramic pacesetters and ceramic moves heat better then steel so that alone will add power. Plus i did lift my car up and look under it and the pacesetters' tubes and end piece that connects to the exhaust pipe looks wider. So i do believe that the exhaust manifold is pretty good stock but i still believe that the pacesetters will still add decent horsepower. Anyone else have any thoughts?