BC Stage 2's shouldn't sound like that. What's the base idle set to? That's more like BC Stage 3 idle at 900~950rpm. Then again, what type of exhaust are you running? If that's a catless resonatorless 3", it makes more sense.
Double check timing for sure. I was off one tooth on the crank with my BC STG 2's and that's exactly what it sounded like. After 4500rpm the car would lose power like you slammed on the brakes. 2.5" exhaust at the time.