AVO S1B03G4VB001J Induction Panel Air Filter (2008+ Impresa/WRX/STI / 05-13 Legacy GT/ 05-18 Outback XT) AVO designed this turbocharger kit specifically for the Mazda ND AVO includes all the necessary supporting components The reduced back pressure of the AVO exhaust system as a whole gets rid of the terrible dip in the torque curve, and the improved flow increases performance