Umm in theory. Welcome to RCNT, and if you were to start a new thread telling what vehicle you have and your intended use, I'm sure we could help you much better! ;)
Theoretically. Given the same battery, yes a higher Kv will be faster.
(No load speed)
On 2s only:
2200 Kv =16,820 rpm
2650 Kv = 19,620 rpm
3800 Kv = 28,120 rpm.
4600 Kv = 34,040 rpm
The 4600 will most likely only handle 2s.
For 3S you would multiply the above rpm by 1.5.
As such for 4s, the...