VEX IQ Speed with Controller

Hey All.

My class is wanting a mario-kart type of game where we have a remote-controlled bumper-car setup with bumper, touchled, and optical sensors.

We would like to have the car start 60% velocity and turn power, until the car runs over a red sticker on the ground, at which point they would have a power up of 100% speed velocity for 30 seconds.

we can’t figure out how to set the speed to 60% while using the controller.

anyone have a solution to this?