I'm running right now! Lol

[sumguy75]

Higher Kv motors are faster if the gearing stays the same, but that also increases amp draw, heat, etc. You can gear up a lower Kv motor so you don't necessarily have to have a high Kv motor. Larger motors mainly provide better torque and heat dissipation. The higher you push the speed, the more things you have to pay attention to if you want to avoid burning up a motor or esc. Unfortunately that is about the extent of my knowledge, speed runners could tell you way more than I could. Most speed runners use a calculator to figure out the combo for what they are attempting, like this one:

https://www.rctalk.com/rc-tools/rc-car-speed-calculator/