TC's and manual trans (was: Re: Smooth strategy)

[Gary Derian]

A torque converter must have at least three elements.  The extra torque
comes from the reaction at the stator.  Its the hydraulic equivalent to a
lever and fulcrum where the extra force comes from the fulcrum.  A torque
converter is not more efficient than a fluid coupling but it does multiply
torque when it is slipping adding an extra gear for starts.  At low slippage
(cruise conditions) the stator freewheels and a torque converter reverts to
a fluid coupling.  A 4 or 5 element converter would be the equivalent of a
compound lever.

Gary Derian <gderian at cybergate.net>

<snip>
>Efficiency is much higher with a torque converter. Very few torque
>converters were two element, as the "stator", analogous to the
>multiplier, was so much more effective with the curved blades. Instead
>of the oil coming off the turbine trying to slow down the impeller, it
>is redirected to the turbine, giving off more of it's energy the second
>time round.
>The ford-o-matic was one of the first to use a three member TQ, along
>with later Powerglides,torque-flytes and cruise-o-matics..
>Lockup TQs are nothing new - Studebaker used a 4 member TQ in the late
>50s or early sixties with a direct drive clutch.The Dynaflow used a 4
>member TQ - or twin turbine converter.Early PowerFlytes were also 4
>unit. Some of these used a variable pitch turbine. The early Powerglide
>and Turboglide used 5 member converters - two pumps, two stators, and
>one turbine.
>Just a "short" history and description of the Torque converter.