Quote:
Originally Posted by EndlessAzure
Torque convertors always operate with some slip unless there is a mechanical shaft lock. When there is slip, the torque convertor and input shafts are spinning at slightly different speeds.
A special benefit of torque convertors is that when they are operating with very high slip (called the stall condition), they offer torque multiplication (like a mechanical gearing advantage). Torque delivered from the engine gets multiplied by a factor significantly more than 1:1 (usually ~2.5:1), resulting in a higher output torque to the gearbox.
However, torque convertors only really encounter stall when starting from a dead stop and within a certain RPM range above that. Therefore, if you can increase effective stall condition and increase multiplication RPM range, you can benefit for longer from additional mechanical advantage for launching the car, since you deliver more torque to the wheels.
Once the torque convertor is no longer in stall or acceleration condition, you no longer have torque multiplication. Torque input is much closer 1:1 to torque output to the gearbox.
- The final logical question is: why don't torque convertors always operate in stall mode if you get a performance boost?
- Answer: Excessive slip generates excessive heat, which will quickly overheat/breakdown the ATF and ruin the gearbox.
|
Thanks a lot for the answer , it really explain in a nice and clear way.
I really like the way you high light the impact , the ATF overheat , and the potential risk for the gearbox.
According to the SSP web site , the twins have a factory stall of 2540+/- 150 RPM , and their SSP A960E will raise 500-700 RPM. I did a quick math , that means possible 2890-3390 rpm for the stall condition.
Does it mean , if I consistently keep my engine running in high rpm , let's say 4000-7000 RPM , I won't feel the advantage from such aftermarket Torque Coverter ?
Is my understanding correct?
Again , thanks for the nice explanation.
