rpm question

[hector]

if you were to go from a 520 final to a 539 final how many rpms would you gain is thier some sort of formula to find out?

[engineczar]

5.39/5.20=1.036 x current rpm = new rpm at the same speed

If you were turning 7000 rpms before you'd now be turning 7256

[84Dave]

Good, quick work Czar. Simple Rule-of-Thumb? For every .1 final ratio change within the drive-train, the engine rpm will change, up or down, right at 125 rpm. -Dave-