well it all depends, you'd first want to modify your computer to take out the limiter and then beyond that since the I4 is an iron block you can throw all the shit you want at it. if you go as far as a twin turbo setup with performance intercoolers and upgrade all the electronics and ignition and redo the exhaust system and maybe throw some nitrous at it along with some other stuff you could probably top out to around 170 with the right body kit for aerodynamics.... MAYBE. but if you're talking stock the I4 won't do much more than around 120-140 im guessin. remember you're dealing with a FWD car that is fairly new to anything resemling high performance.