In an effort to elaborate on this post:
http://dsmtuners.com/forums/showthread.php?s=&threadid=110166
and to answer what is a frequently asked question, I will attempt to explain the difference between a stock and a performance torque converter, in relation to stall speed.
I will try keep it as simple as possible but will be happy to go into further detail if anyone has specific questions.
A high stall converter differs from a stock converter in the sense that the rpm is raised at which the internal converter components- the impeller, the stator and the turbine start to turn together, and hence, stop the torque multiplication phase and begin the coupling phase.
The idea behind a higher stall converter is to allow the engine to rev more freely up to the point where the powerband begins, and therefore, enable it accelerate from a stop under more power.
This becomes increasingly important when an engine is modified. Engine mods such as ported heads, bigger cams, bigger turbos (in some cases), bigger intakes, etc. tend to raise the point where the powerband begins. For best performance, the stall speed needs to be raised accordingly to work optimally in conjunction with the given vehicle alterations.
In simple terms, for best performance, the stall speed should be raised at least to the point where the torque curve is heading for it's peak. As a rule of thumb, the stall speed should be set to match the rpm at which the engine is making at least 80% of it's peak torque for a street driven vehicle.
As you can imagine, a vehicle that can accelerate from a stop with 80% of its peak torque will easily outperform the same vehicle that can only launch at 50% of its available torque.
-John
http://dsmtuners.com/forums/showthread.php?s=&threadid=110166
and to answer what is a frequently asked question, I will attempt to explain the difference between a stock and a performance torque converter, in relation to stall speed.
I will try keep it as simple as possible but will be happy to go into further detail if anyone has specific questions.
A high stall converter differs from a stock converter in the sense that the rpm is raised at which the internal converter components- the impeller, the stator and the turbine start to turn together, and hence, stop the torque multiplication phase and begin the coupling phase.
The idea behind a higher stall converter is to allow the engine to rev more freely up to the point where the powerband begins, and therefore, enable it accelerate from a stop under more power.
This becomes increasingly important when an engine is modified. Engine mods such as ported heads, bigger cams, bigger turbos (in some cases), bigger intakes, etc. tend to raise the point where the powerband begins. For best performance, the stall speed needs to be raised accordingly to work optimally in conjunction with the given vehicle alterations.
In simple terms, for best performance, the stall speed should be raised at least to the point where the torque curve is heading for it's peak. As a rule of thumb, the stall speed should be set to match the rpm at which the engine is making at least 80% of it's peak torque for a street driven vehicle.
As you can imagine, a vehicle that can accelerate from a stop with 80% of its peak torque will easily outperform the same vehicle that can only launch at 50% of its available torque.
-John
