Back on topic:
Yay a kart Racing thread
I've raced karts for better part of 23 years and competed in virtually every single type of kart there is! Won national championships and competed at European and World Level. To go into everything about what can and cant be done to drive faster is a MEGA topic that a whole lot of factors come into, some of which have been addressed.
Firsty: Power of the kart - The less power you have the smoother you need to be and the more critical Weight is. Weight is a MAJOR penalty even for a kart with double the power, 5 kilos can be two tenths of a second lost! The only time weight is an advantage is in the wet, where it helps cornering. The more mass you have to move around (in corners or on the straight, the more is required of the tyres or engine to do so) with more power you can get away with more and driving styles have less, if any penalty on the performance and it starts to come down to personal preference, but on rental karts: BE SMOOTH! Every squeal of the tires is lost speed
Grip: how grippy is the track? generally for rentals the tyres are very hard and grip is minimal with little or no meaningful rubber laid down on the track. With this the need to raise the inside wheel becomes less imperative. This behavior is governed by the setup of the kart and how Stiff it is. I doubt a rental kart will ever be able to raise an inside rear but indeed this is what you will see karts doing at high levels. WHen rubber gets Crazily laid on the track things change again. It becomes a completely different style of driving (This is typical in things like world champs where very sticky rubber is used). Its bonkers, I could never get used to it. So try to keep that back end in check, every slide is lost speed .
So be smooth! Try to maintain speed through the corners as much as you can and carry it onto the next straight! you may brake a little earlier but if your engine doesn't have to do as much work on the next straight you will come out on top! Also, rental karts are NOT created equal, some will be dogs and some will be good. Try to jump in one that won the previous race or you have used before (dont be fooled by ones piloted by some 60 kilo guy
) Really these karts scrub so much speed off just by turning the wheel its amazing !