For Audi TT/VW Bettle/Jetta/Golf Mk4 1.8T K04 Turbocharger Turbine A/R .70 + 30 psi Boost Controller (Red) Increase Engine Power and Torque Outpout; Maintain Combustion Chamber Pressure and Fuel/Air Load Contructed with High Quality Material; Built for Durability and Strength; 20 psi Efficient Torque Turbocharger; Internal Wastegate Setting: 8 psi Capable of Boosting Horsepower up to 400+ BHP / Exhaust (Turbo Manifold) Flange: Standard 3-Bolt / Exhaust (Downpipe) Flange: Standard K04 TD05 5-Bolt Inlet/Outlet: 2.25"/1.375" / Compressor Inducer: 42.3mm / Turbine Exducer: 42.3mm / Turbine A/R: .70 Boost Controller: Made of Aluminum, Adjustable 1-30 psi