Hydraulic transmissions feature TCC (torque converter clutch) lockup. It’s a great feature but yet another thing to configure 😉

GCU uses a couple of tables to define how TCC should be operated:

  • TCC Engage RPM:
    • Defines above what RPMs (X) at (Y) Gear TCC will be engaged.
      Depending on purpose of the car, torque characteristics, spool line and fuel type engagement points will be different – for example big torque gasoline engines for street would prefer having TCC engaged as soon as possible, while off-road cars would definitely benefit from late engagement.
  • TCC Disengage RPM:
    • Defines below what RPMs (X) at (Y) Gear TCC will be disengaged.
      Similar story to TCC Engage table, but it’s worth mentioning that this is very powerful table for spool-aid. Consider free RPMs for sooner turbo spool-up 🙂
  • TCC Prefill Pressure:
    • Once TCC Engage RPMs conditions are met, the TCC is prefilled with defined pressure…
  • TCC Prefill Time:
    • … lasting defined Prefill Time in [ms]
  • TCC Engage Time:
    • How long transition from TCC Prefill pressure to full pressure lasts.