When I had mine I had a cat back system with 3inch back back, apex super filter and iridium plugs and pi 40mm springs I had complete interior with 12'' sub Starletsr? Had a backbox, iridium plugs, pi 40mm springs and stripped out completely We were evenly matched every time we raced so I can't see why you can't get that speed :-/ sure you clutch isn't slipping so your not getting all that NA power planted ? James