Description Subaru KX21 4 stroke Gokart engine performance header pipe part number AS0284 Aussiespeed AS0280P long series 2 piece muffler includes 2 connecting springs to connect the header pipe to the muffler . This press bend header pipe suits Subaru go kart engines & increases performance & torque for use on road type courses where rpm varies. The AussieSpeed Subaru go kart engine header pipe has a fully welded spring coupler for easy fitment of AussieSpeed AS0280P long muffler. This is a full exhaust system for Subaru ex17, ex19,ex21, ex27 & kx21. a muffler to chassis mount is not included in this package & needs to be purchased separately