[lincpimp]

800g of lipo is going to be very heavy in a buggy. Why not go down to a smaller lipo? Also, a 9xl is 4-5s motor. Not sure if the rotor wil lstay together when run on 8s. 1400kv is better for 8s, maybe 1600kv if you have a well made motor.

I would try to keep battery weight around 400-500g. And a 1512 size motor of 1600 kv or so will be a great place to start.