[Alan Roehrich]

A good torque converter multiplies torque at between 2:1 and 2.25:1, approximately, at the RPM it flashes to, and the torque multiplication begins to taper off as engine RPM exceeds that flash RPM, the more the engine RPM exceeds the flash RPM, the less the converter multiplies torque. Slippage is the price for this torque multiplication. If you work with the converter company and both of you do your job well, the slippage should probably get down to around 4% to 8% (on a higher HP car, some low HP cars never get close to a low slippage percentage). As you go from flash RPM to your peak RPM, slippage decreases. You can never completely eliminate slippage, but you can get close.