Drive a good line
Scale chassis out good
Make necessary adjustments but only one at a time
Work
Your tires
Attempt things to see if it makes you faster sometimes it will make you slower but you never know until you try
Consider changing things on kart to better work when track isn’t at its best like in a heat race then change those things for when the track had come around when feature time
Make sure you do good maintenance and stuff like that
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Recently there was a question posing the same concern. Lots of good advice in that thread.