Description Subaru KX21 4 stroke Gokart engine performance header pipe. This 1 inch header pipe suits subaru go kart engines & increases performance & torque for use on road type courses fun & social go karts where where torque & power is required over a wide band. The AussieSpeed AS0281 Subaru go kart performance header pipe is designed to be used with AS0278 short style muffler. you are purchasing the AussieSpeed Power Pipe only. The muffler needs to be purchased separately The AussieSpeed Subaru Performance header pipe features 1 mounting straps & a fully welded laser cut flange Power pipe package can be supplied with AussieSpeed Muffler & Muffler Clamp in painted or chrome finish