Before and after videos showing SC Project exhaust fitting, the dB killers are removed from the SC cans in the entire video.
Standard exhaust for a sound reference
SC Project S1 Titanium cans with OEM cat
SC Project S1 Titanium cans with arrow decat
The system with decat and cans with dB killers removed is damned loud, it is 103dB @ idle and 112dB @ 5,000rpm (50cm away at 45*) measured using a calibrated sound meter.
Overall I love it, but you'll need a good supply of earplugs !
