RPM's

On my truck all i have is a FIPK and an exhaust. I dont have any type of power chip or programer... But I can still get it to to up to 5800 RPM's if i reall step on it and hit it at the right time. I thought the point of gettin one of thoes programers was so you can do that, but my truck seems to be doin it on its own. Or is a programer so u can set it so shift at different rpm's and not always go so high? im confused :confused:

Its for both really, the handleld tuners will let alter your shift firmness, change your shift points, and also let you raise the rev limiter (to say, 6000) and also let you bump the top speed limiter up to 128mph.