ok i know there is a formula somewhere couldnt find it....if you run say a 2.0 60ft and bring that down to say a 1.8 or high 17s...how much should that take your ET down? example....say you ran 13.1 with a 2.0 60ft now you can hook do to drag radials...etc etc...and now ran a 1.8 what would that net you?