Kart racing rocks! I raced karts for 2 years and then moved up to a formula car in the SCCA. Racing karts was more fun and a heck of a lot less money. They have classes for kids and adults. I had about $3500 into my kart. I spent maybe $50/week to race. Cheap fun. They pull 2-3Gs in the corners.
WKA is a serious league...a good friend races Alky briggs class or something like that...his cart is insane. it was monitored doing just over 110 or so in the draft around Daytona Int Spdwy. be careful though...a good few of his buddies have been killed racing.
I used to race karts. Back in the day, it was fun. I have a 125cc shifter kart that I havent driven in some time. Down the front straight at PIR 125mph.
i have a 125cc shifter as well. i road race stock cars and this is what we use to train with. when you get these things on a kart track, things happen at the same rate of speed as a fast open wheel car. nothing like F1 or champ car, but more like an atlantic or formula mazda. id say they accelerate like a 450rwhp fox. theyre tons of fun as well as an awesome training tool.