Lap times, temperatures, speed, and other data values or sensors are common in race karts, and you’ll generally see two brands of systems on karts today. Aim Sports Mychron being the most common, and Alfano Gauges. Both are professional karting computers and what you go with is a personal choice.
With the Mychron System being more widespread, we’ll largely focus on their system.
The current generation of karting computers include the Mychron 5s and Alfano6
Both of these have GPS onboard, which allows them to provide speed, and GPS position on track, engine rpm, and lap times as part of that as well.
Basic common sensors are temperatures for Exhaust, Water, and Cylinder head Temp taken from under the spark plug. These are usually included with the head unit, and specific to your kart setup, an example being that you would not need a water temperature sensor for an air-cooled KA100.
These head units also measure cornering G and provide expansion to include other sensors like Throttle Position, Steering Position, Brake Position or Pressure, Tire Temperatures, and the Air-fuel Ratio (Wideband Lambda o2 Sensor).