Advanced Rpm Control Module (Arc) Universal Traction Control/Slew Rate Module MSD IgnitionNow there is even more control with the PN 7761 module for the Power Grid System Controller. This module sets rpm limits based on slew rate (rpm acceleration) or based on time since launch. All of this is programmed seamlessly in MSD View. The ARC module stands for Advanced RPM Control, it basically allows your race car to remain consistent, pass after pass, controlling your engines rpm curve during a pass. This helps you get down the track quicker