hey there, well if you go to the mazdamp3.com website you can find every you are looking for about the speed. As far as fuel mods you are o.k. even if you boost it up to about 10 psi. The mazdaspeed runs rich from the moment you start it up all the way trough high rpm's. Everyone has something to say about how shitty the car was built and its non-forged internals, but no one has a clue how strong this motor is. Add a three inch turbo back exhaust, a cone filter and a boost contoller(9psi) and i guarantee 210whp+. And i can promise that, do it and put it on a dynoand you'll see. Other than that if you need anything put up a post and i'll help out.