What this table does
This table sets the PWM duty cycle sent to the torque converter dump valve. The dump valve controls how much charge pressure the converter sees, and that changes how the converter behaves: how easily the engine can rev up into it, and how tightly it couples once the car is moving.
Why you'd use it
At the start line, bleeding off some charge pressure makes it easier for the engine to "come up on the converter", reaching the rpm and boost you want to leave at. Once the car launches, you can bring charge pressure back in, either immediately or gradually during the pass, so the converter couples up and stops wasting power as heat.
Axes that make sense for this table:
- Race time: the most common. Low charge pressure on the line, then bring it in at set times after launch.
- Engine rpm: relieve pressure until the engine reaches launch rpm.
- Road speed: bring charge pressure in as the car accelerates.
Change one thing at a time, and log converter slip along with rpm and boost. Converter behavior can change with fluid temperature, so compare runs at similar temperatures.
For the rest of the converter setup, see torque converter control, including the lock point and lock duty cycle.
