hi. ive done like 5 years worth of research and im still not getting this tuning deal. forst of all which one is better the diablo sport tuner or the SCT? and whats the difference between the Sf3 and the xcal3? i just done get whats going on. i have exhaust and Intake mods so dar and im runnin 93 anyways to help the idle. all this "parameters" stuff is scaring me and i dont wanna pay more money to go to a dyno shop so they can do it. i need the serious run down from day of purchase to the second of maximum power increase yeild.