Jammin x2 cr geared 46/16 too slow?

[superek4]

I am racing my x2 cr jammin geared 46/16 with rcm slip diff 1512/2.5 2050kv.

The alysum software says it's about 31mph. Temp is about 60-70 degrees not farenheit when I raced it last race.

My race track is bumpy/rocky & quite big.

What you guys think is it fast enough?