I kinda think this was beat down due to nobody could agree on anything. 240 and myself had custom ones built. He didn't like the noise on duals and sold it. He also stated no HP/TQ gains with this but picked up HP/TQ with a 3" custom single pipe. I'm still running my duals they are loud, as far as gains, I have no idea after my car is finished I will dyno and tune, but I'm doing it all at once so I have no individual breakdown.