well just about, compression is a lil different over there, but using an s4 engine, u could most def create an rs4 engine. there was an article somewhere that someone converted their s4 to rs4, like a real conversion, dumped liek 100+k into it or somethin, every part from the rs4 he has, it looked stock too when u seen the engine.. he was pumpin out 480 hp

 

not worth the money