first mods to virgin z went like this.pro design billet adpt.k+n with outer ware,pro-c t4 slip on,dyno-jet needles+main 146,3 clip from the blunt end,mixture 3 1/2 turns out.removed snorkel, lid on.gains were obvious,crisper throtel responce+broader power!remove the snorkel get the filter kit,up the jet,+you should notice a slight increase in power,it can only help.