Our stage 4 kit includes a custom tuned flash rated at 650Hp on 93 0ctane.  We offer custom race gas files as well when the 5 tune option is selected. This kit includes our 63.5mm billet VTG compressor wheels( good core required) but can be substituted for Zona Tial 65 mm compressors at an extra charge, our custom muffler  X design exhaust with EPA approves cats(dual tips additional cost), and our  4.5″ Race intercoolers. Optional matching 2.5″ competition Y-pipe is strongly recommended for better flow.