Torque Converter
The short answer is that a torque converter's job is to transfer available torque to the rear wheels.
Most aftermarket torque converters have a higher "stall speed" than stock.
Among the trade offs are sometimes higher transmission fluid temperatures, which over time, and if high enough, can lead to premature automatic transmission failure. Some use an auxillary transmission cooler to address this problem.
This is good reading:
http://www.converter.cc/frequently_a...uestions.htm#1
http://auto.howstuffworks.com/torque-converter.htm




