i recently bought a havok 17.5 spec brushless system for my tamiya tto1, but it goes way too slow

i have a 61t spur gear(stock) with a 21t pinion gear in it and im wondering if i gear it with a 55t spur gear with a 28 pinion gear, will it make a big difference in speed(something that i can notice) or will it just change it tad?