Rotax MAX Jetting vs GridCall

The Rotax MAX Jetting App enables the user to calculate the optimal carburetor main jet size for Rotax kart engines of the MAX series: - 125 Micro MAX evo - 125 Mini MAX evo - 125 Junior MAX evo - 125 Senior MAX evo - 125 MAX DD2 based on the current ambient conditions - Temperature - Altitude - Air pressure  - Humidity This can be done either automatically using GPS and a functioning internet connection or manually by entering the ambient parameters. *Automatically* Click on Use GPS position for weather data, select the desired engine type from the scroll menu and start the calculation tabbing the Calculate button. *Manually* Enter all ambient parameters, select the desired engine type from the scroll menu and start the calculation tabbing the Calculate button. Important: Since the calculation is based on the "relative air pressure" (air pressure at 0m above sea level), your own barometer must be calibrated to the current altitude before you can actually use the value. Online weather services provide this value by default. To toggle between Celsius and Fahrenheit, press °C/°F and to choose between meters and feet press m/ft next to the entry of the value. To start a new calculation, click Reset.

"Hey, when is my next session?" GridCall answers that question all weekend long. Live schedules, session countdowns, and paddock info for karting race weekends — heats, scrutineering, driver changes — published once by the organizer and updated on your phone the second they change. No group-chat scrolling, no photographed timetables. Follow the Rotax Max Challenge Switzerland and Rotax Max Challenge Italy weekends from one app: pick your category, and GridCall keeps a countdown to your next session on your iPhone, your Apple Watch, your Lock Screen, and your home-screen widget. Offline-first by design — a bad paddock signal never costs you the plan. GridCall is built for everyone at the track: drivers who need the next call, mechanics planning the stint, and families who just want to know when to be at the fence. Race series and event organizers can run GridCall in their own colors — visit gridcall.ch to see it in action. GridCall® is a registered trademark.