World Record 45 AMG Stock : 329whp / 311wtq . Pump Gas Meth 536whp / 499wtq on Dynojet Thanks to 馳神車業 CSPT EPD Motorsports AMS Performance Exhaust come with valve as standard including our intelligent ECU system which control valve by engine RPM or remote control. Video Fitted with FI Complete Exhaust System includes: Catback Valvetronic Muffler Dual Tips Ultra High Flow Catless DownPipe For more product information Please visit http://www.fi-exhaust.com/product/mercedes-benz/w156