How to make my buggy faster?

[superek4]

My jammin x2 only accept max 16 size pinion with 46 slip diff. I m using 1512/2.5d neu. Batt is 4s 5000 zippy@30c.

My EPA is 150% punch at 50%. I tried 70% it's hard to drive. I was thinking the only way is to change higher kv motor.

Anything else I can do wo spending?