These engines come from the factory with no diverter valve of any kind, which results in turbo compressor surge every time the throttle is closed after boosting. The intake is acoustically tuned to suppress the fluttering sound of compressor surge, but it does not eliminate the effect of pressure pulses that is what diverter and blow-off valves were originally designed to do. The GFB VTA re-introduces a blow-off valve into the 1.2/1.4 TSI system, which eliminates compressor surge to protect the turbo, and delivers the signature blow-off whoosh when lifting off the throttle.Because these engines do not run a MAF sensor, there is no chance of adverse drivability or fuelling issues. The VTA clips directly into the turbos charge piping, replacing a short plastic joiner with a billet CNC machined section onto which the VTA mounts. The kit also includes a boost tee and vacuum hose that clips onto one of the manifold vacuum ports to source a vacuum signal for the VTA valve. This boost tee has a second port that can be used to connect a boost gauge (not included), or plugged off if not required. The whole kit can be fitted in minutes with no tools.