I just replaced my Stock Exhaust with a Spoon N1 with Custom B pipe. NO RESONATOR... Well IT is WAY louder than Stock and a bit Louder than if I had gone with a resonator. I will be adding a resonator SOON. Although I use the Sub silencer the system still can use the benifit of a resonator.. As for FLOW WOW is what I have to say you can immediately feel the better flow in the pedal feel if you can believe that. No Dyno results cause the car is not finished