A video to explain torque converters

[Mike]

This video will help explain some of the mysteries of torque converter design, selection and use.

The major points to take away from this video are -

• engine torque, vehicle weight, gear ratios and even brake condition can affect the stall speed of a torque converter
• an engine's camshaft and torque converter are inseparably joined at the hip
• until a torque converter is at maximum fluid coupling (which is never 100%), the lost transfer is producing heat

 

[Mike J]

This video will help explain some of the mysteries of torque converter design, selection and use.

The major points to take away from this video are -

• engine torque, vehicle weight, gear ratios and even brake condition can affect the stall speed of a torque converter
• an engine's camshaft and torque converter are inseparably joined at the hip
• until a torque converter is at maximum fluid coupling (which is never 100%), the lost transfer is producing heat

Good video, I new the workings of a converter but not what stall speed really is. Or how to choose a converter based on the cam, weight etc. I forget that youtube is a good place for video info. Thanks

 

[Screaming Metal]

OK, think of stall as this....a centrifugal clutch on a gokart. If you ease on the throttle, at a certain rpm, your kart starts to move, pulling gently until the clutch is in full lockup.
Now, stall speed is the speed at which 85-90% of total lockup will occur UNDER FULL POWER!
Fluid Dynamics, a turbine wheel is spinning at motor rpm (Converter housing), with another turbine wheel just a inch or so away from the first on. Now, instead of blowing air, your using a thin fluid such as Automatic transmission Fluid. Thats the reason why you can have your foot on the brake and stop the car.
The Stall speed is the angle of the vanes in that turbine wheel, as the fluid moves thru the driven turbine, to the trans turbine (Stator). The steeper the angle to 90 Degrees the vanes are, the more slippage occurs. The less steep the vanes, the lower the rpm your converter has to be spun to move the car. The diff. in the pitch between the stator and the housing....gives the converter its unique characteristics.
The point to where the engine makes the car take off like a std shift with a clutch at....is the stall speed. Stall speed is your launch speed. Flash stall is where the converter 'seems' to 'lock up solid'.....thereabouts. This is in laymans terms so you can understand.