GFB Mach 2 TMS Recirculating Diverter Valve 2004-2021 STI

Blow off sound not to your taste? Want something as “sleeper” as possible? Don’t want your partner to know you’ve stuck a turbo on the daily (again)? Then the GFB Mach 2 is the valve for you!Using GFB’s TMS technology the Mach 2 can help return the engine to peak boost up to 30% faster than a factory diverter valve when shifting gears (more information below).The Mach 2 is available in a range of universal and bolt-on kits for most popular turbo models. And when we say “bolt-on”, that’s exactly what we mean! No additional adaptors, parts or vehicle modifications are required – simply remove the factory bypass valve and replace it with the Mach 2 – it’s that simple!The Mach 2 is configured as a 100% recirculating valve (i.e. bypass, plumb back) as a direct factory replacement, for when you want all the performance WITHOUT the noise!Why replace the factory bypass valve? Better performance! Factory bypass valves typically have two main shortcomings – one is that they are often designed to blow open above a certain pressure to protect the engine (if you drive an EVO, take note and read this article!), and the other is they are not optimised for throttle response.The Mach 2 solves both issues. With its pressure-balanced design, the Mach 2 can effectively hold unlimited boost (unlimited in that no turbo could ever produce enough pressure to damage it), and the TMS technology ensures maximum throttle response.