Originally posted by Issue For Trust
I was wondering if the CA18 would be considered as one. I didnt post it becuase i wasnt sure, but thanks, now i do 
the s15 has a 6spd as the s13-s14 have 5
They are still SR20DETs though my friend, and they are still Silvia engines. S13, S14, and S15 are just chassis codes for the Sivia/180/240.