The Mercedes M275 and M279 Biturbo V12 engines found in the AMG 65 models feature plastic bypass valves that are installed the the compressor covers of each turbo. The bypass valves are prone to leaking, especially on vehicles that have an ecu upgrade with higher than stock boost levels.
Weistec M275-M279 Anti-Surge Valves (ASV) replace the factory bypass valves with a bolt in installation. The system produces the infamous and sought after “blow-off” sound. This upgrade is a must for vehicles that have an ECU upgrade as the factory valves leak and reduce turbocharger efficiency and performance.