ok i got a 97 civic EX with a D16Y8 with cold air intake, hi flow cat, and cat back exhaust. the exhaust is 60 mm (2.36 in ??) piping. the rest is stock performance wise.

i am trying to figure out how to make a turbo and what size downpipe i need so it spools around 3-3500 rpm's and will peak around 7500 rpm's.

if anyone can help on this id really appreciate it