read
http://www.ubrf.org/forums/showthread.php?t=25290&highlight=butterfly
and
http://www.ubrf.org/forums/showthread.php?t=41337&highlight=butterfly
and for oil read this:
http://www.nissanperformancemag.com/june06/oil/
Once you have taken care of those things start modding. Until then you are driving a potential time bomb…:shrug: