What the table does
When the Traction Control method is set to Cut Percentage, the ECU reduces power by skipping a share of ignition or fuel events. This table sets how large that share is. The input is Traction Control Slip Error, and the output is the cut rate: the more the tires are slipping beyond what you want, the more power is taken away.
Understanding slip error
Slip error is measured wheel slip minus the value from the desired slip table. A small amount of slip is actually where a tire grips best, so you aim for it rather than zero.
- Positive slip error: the wheels are slipping more than you asked for, so the table should apply a cut.
- Zero or negative: slip is at or below target, and there's no reason to take power away.
How we start tuning it
Keep the cut at zero for zero or negative slip error, then ramp it up gradually as positive slip error grows. A gentle ramp near zero stops the car from stuttering over small bumps, while the bigger values catch real wheelspin. Set the first values conservatively and adjust from logs of slip error and cut rate, rather than by feel alone. If the car bogs, the cut is too aggressive. If it spins through the intervention, it's too soft.
This table can only react to the slip the ECU measures. Make sure your wheel speed sensors are set up and wired correctly, as described in traction control wiring, before you spend time on the cut table. The full picture is in traction control.
