ok i have a gs-r which is mostly stock. awhile back i burnt a valve an while i had it down i put itr pistons in it which ups the compression to 11.5 if im thinking correctly. well with that high of compression it doesent sit well with boost. but i want to turbo my car. now in my opinion i can still do it but i dont think i can go over 5psi an have a good tune. now i would like to open the thread to the smart people that have helpful answers. thank you.