hi hi kylim8
If u want to mod your s15 to 450hp then u only need to change all your eng head set to
HKS step 3,
Greddy T67,25g turbo and
Power Fc ecu.
Hope this list can give u some ideal
You guys were extremely helpful in answering my previous query, so here I am once again with a few more "nooby" questions. Hope you guys will be able to help once again.