Apr 14, 2020 · Sprint booster vs Pedal Commander Discussion in 'Engine & Performance' started by Keith Stefan, Apr 14, 2020. Page 2 of 2 < Prev 1 2. Sponsored By: Apr 15, 2020 at ... The RaceChip XLR is installed between the throttle pedal sensor and the engine control unit. Depending on the XLR’s tuning stage, it either amplifes or reduces the signals sent by the throttle pedal sensor in accordance with characteristics defined by our engineers. The effect is that you can choose how your car reacts to your throttle inputs.