Thank you. Coutie; I'm trying to limit the power, torque and change the gearing in the JR kart to micro/bambino series. I'm trying with upgrade.ini, so far so good limiting the power and torque; but when I try to change the gearbox definition file to the one i created, the games crash when loading. My K100_updrade.ini file looks like: UpgradeType="Category Level" { UpgradeLevel="Jr Category" { Description="Default performance level for JR Category" } UpgradeLevel="Micro Category" { Description="Micro Category performance" Price=1 HDV=[DRIVELINE] HDV=GearFile=K100_Micro_Gears.ini HDV= } Any idea why the game crash when i change the gearfile to a custom one? Also, I can not use mode dev for this model because part of it is inside a encrypted mas file.