I would suggest that you bring your rope length in to about 65 to 70 ft at a speed between 20-22 mph first. if you are just learning how to go wake to wake, 80ft is much too long. and make sure you keep your edge all the way thru the wake so that the most energy in your cut is at the point which you leave the wake.
but once your wake jumps are strong and you want to ride further back 80 ft should probably be driven at about 24-26 mph.
good luck. hope this helps