To max out the stud counter you will need a total of 4billion studs which can be achieved with the multipliers (2x, 4x, 6x, 8x, 10x) all turned on. These multiply together so. (2x4x6x8x10 = 3840) which will bassically net you any where from 100mil - 500mil each level. I reccomend you play Episode 1 Chapter 4 - The pod race as it take 3 mins to complete and nets you at most 241mil. so if you played this 16 times for 1 hour this achievement would be yours.