13. On the next run, we noticed a drastic change in the power and torque curve. At 5,400 rpm, both curves abruptly changed direction at the exact same time. There was no curve to the change; it was like the graphs bounced off a wall. Thinking it was an electrical issue, we swapped the MSD ignition box for a new 6AL box Rolenc had waiting for another engine. Once we swapped the boxes, the engine no longer broke up at all, and cleanly revved to 7,800 rpm.