?The Weistec ASV/WM Injection System adds multiple beneficial components to the M157 BiTurbo 5.5L engine. ?First being the addition of a Weistec Anti Surge Valve (ASV). ?From the factory the M157 engine was never given any type of bypass valve. ?With out a bypass valve, the turbochargers are subject to compressor surge when the throttle closes after hard acceleration. ? Compressor surge can be damaging to turbochargers and generally should be prevented to help ensure the best performance from the turbochargers. ?The Weistec ASV is operated by the engine vacuum, opening when the throttle closes allowing the?compressed air to be vented to the atmosphere instead of back flowing into the compressor housing and stalling the compressor wheel. The vented air produces the "blow-off" sound common on many modified turbocharged vehicles.
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Second, is the Water/Methanol Injection (WMI) System. ?Water/Methanol injection has been in use for several decades in multiple applications. ?Originally, it was used to reduce knock while increasing power and performance in aircraft engines. ?Eventually it came to be used in the motorsports industry where it was found to have substantial benefits on turbocharged engines. ?The Weistec ASV/WMI System features an ?Water/Methanol Controller with built in MAP sensor. ?This controller is a progressive controller that slowly increases injection as boost builds, resulting in smooth and seemless operation. ?The included Turbo Charge Pipes each have a built in bung, allowing the use of two injectors for uniform injection and cooling. ?The combination of the cooling effects of methanol and the knock resistance of water result in significant gains in horsepower* and torque* as well as reduced chance of heat soaking the intercooler system.
This system is a complete, bolt on system that can be installed with out any guess work or custom fabrication. ?Weistec has engineered and manufactured many of the components of this system to ensure a simple and straight forward installation. The gains in performance and consistency make this system an essential upgrade for the M157 engine.
