In NSP's sequential twin turbo control, the Secondary Off RPM table sets the engine speed at which the ECU deactivates the secondary turbo. It works as the other half of Secondary On RPM, and the table can be mapped in up to three dimensions, so the switch-off point can change with a second or third variable rather than being a single fixed number.
What to check: keep the off point comfortably below the on point so there's a gap between them. If the two are too close, the system can flick back and forth when you're cruising right at the transition, which feels like surging and is hard on the valves. Log RPM, boost and the secondary state together to confirm the changeover is clean in both directions. Check your sequential wiring if the state changes but boost doesn't respond.
Need this diagram? Ask us and we'll send it over with advice for your build.
