in terms of NA mods you can read todas modding guide for the f20c. The only problem i find wrong with hondas is that they lack power down low but still are more responsive than turbo cars and are much more ldriveable on a daily basis. By upgrading your final gear and lighter flywheel will give you a much better driving experience than what your s15 would have given you. A friend of mine recently sold his s15 and bought an s2000 and he actually said what i had just typed. His s15 was fully modded as well.