The RennTech lock-up clutch upgrade uses a multi-element clutch upgrade with additional layer of friction material between the clutch plate, better friction material on the clutch face and a larger surface area of friction material to help control slippage. This allows for better heat management and increased holding power.
While slippage in the torque converter is important under acceleration, this slippage becomes a liability once cruising speed is achieved. The lock-up clutch controls this slippage and creates a solid connection between the engine and transmission. If the load on the clutch is too much, slippage can occur leading to excessive heat and wear.