Rotax MAX Jetting vs Fox + Son Jetmax

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.

Precision jetting made easy — This app helps you calculate jetting for Rotax engines based on weather and altitude. Now every Rotax racer has access to the same jetting Fox + Son has used to power our engines to countless Rotax National wins and Grand Finals tickets. After many months of development and testing, we have successfully brought the same jetting algorithms we use on our dyno to a quick, easy-to-use app. We have also included all of our popular Rotax tuning tips that are found on our website, along with a handy interactive gear chart for your convenience. As we do with our website, we will continually update the app as we discover new tuning information. Anytime a new cylinder or part is introduced, all of the testing we do at the shop will flow directly to Jetmax. Jetmax will also calculate the relative horsepower for that atmospheric condition. The relative horsepower percentage is helpful information to have when selecting your gear ratio. In certain situations you can benefit from increasing your gear ratio when HP is low & decreasing your gear ratio when HP is high. Whether you're competing at the track or fine-tuning your kart for practice, Jetmax gives you accurate, reliable recommendations so you can focus on performance. Features: - Jetting calculator for Rotax engines - Calculates relative horsepower - Includes an interactive gearing chart Engineered by racers, for racers — Fox + Son Jetmax App delivers the tools you need to stay competitive on race day. *You must have a valid subscription in order to use this app.