you'd get more power from raising the compression ratio ( might cause detonation and ignition timing issues though so ask a performance shop about that) and getting the cams reground for higher lift, do a higher flowing cat and exhaust, cold air intake, if its a manual, put a lightened flywheel in maybe, and try to get the computer chipped or modded.. How will anyone know if you have high compression or a reground cam, its all internal..
there was a 300zx non turbo on here not long ago, it got down to 14sec quarters, search for what he did cause thats a quick P platers car..
didnt realise it was already 11;1, gees that really is a weak motor