I found a cheat on Animal Raceway. It's when you buy the stripes. If you keep clicking on it you gain 20 more speed. If you know anymore cheats put it here.
I don't think 3120 speed is possible... At least I think. I tried a prehacked game (Note: pre hacked, I did not hack it) and I trained it for a while, all the stats only go up to 1000.
thats weird... i didnt hack (i have no idea how XD) and the max for me was 1012. when i trained it got to 1000 but when i gave an item that gives more it managed to go up to 1012