yes you can tune your car. Also i don't get what you said by tuning off peak horsepower but any way. You can tune your car with the gtech. Here is an example. Say you just put new vtec cams in your car. You have a vtec controller and want to know what rpm to kick vtec that gives you the most hp. You can change the vtec then run your car with the gtech get hp numbers and then do it agian untill you find the best engagement point. That my friend is tuning. Want another example let me know.
Pretty saucy for a SOPHMORE!!!