Im running HPI monster SS wheels with custom foams. 3s ***** lipos in parallel. I tapped my phone to my merv and did 1 pass and it only went 37.51mph. I didnt do more because it handled like crap with all that extra weight on it lol. Its slower than youd think because i run a lower KV motor. I might put my CC 4600kv motor in it just to see the difference. Once i get better at driving ill try my 33t pinon. And if i can keep the wheels on the ground ill but a 35T pinion.