Right, but how high are your revs going and how low are they dipping? I'm just wondering how much room you have left before your bouncing off the rev limiter the whole time.I figure an SR16 box is probably going to do the job, but that's just a guess. Look up the ratios to be sure. They may be in your owners manual if there's a smaller engine'd Sunny of your year. Otherwise try to find the owner's manual of a car with a 1.6 or whatever other options you find.