As RPM continues to rise, torque decreases even further. How would you translate this to a torque converter? With a low stall speed. The impeller input side of the torque converter is spinning quickly, while the turbine output side is spinning slowly or not at all. The motion energy of the impeller is being converted into heat energy, most of which is passed on to the transmission fluid.
The higher the stall speed, the more heat will be generated. Heat is the enemy of a transmission. A converter reacts to two things to multiple torque: force applied from the torque of the engine, and resistance, which is the car.
When the vehicle has a power-adder, that will need to be factored into the choice of torque converters. The reason for that is because no matter what power-adder you opt to use, it will change not only how much power the engine makes, but where it makes it. The heavier a car is, the more load it will put on the torque converter when power is applied, causing it to flash at a higher speed. Gearing plays a part because as you add more gear, it will cause the load on the converter to become lower, while taking away the gear will make the load grow.
Tire height falls into the same function zone as the gearing of the car: as you increase the height of the rear tire, you will increase the load on the torque converter and change where the torque converter will flash. The Stall Speed Range. There can be some confusion that the stall speed of a torque converter is an absolute thing. The reality is that a torque converter has a range of speed that the stall can engage in, and that will change based on the previously mentioned factors.
It only reacts to a situation; it does not dictate anything. The same converter will flash differently when put behind different powerplants or in different cars. Having the correct stall speed range in your torque converter will ensure that power is being applied at the best time during a pass.
Stall speed is a relative term. These types of tests can lead to premature failure of the converter and are not a recommended practice. Before you start calling every torque converter manufacturer trying to gain access to the secrets of stall speed and what your car needs, you first need to figure out what the primary purpose of the car will be. Knowing the combination and its use is the best way for a torque converter company to build a converter to fit your needs. The first thing that you will need to know is approximately where the engine starts to make its power.
Previously, we had touched on the concept that bringing a power-adder into the mix will change how a torque converter behaves when it comes to the stall speed. According to Caine, the stall speed will be different for each, but how you determine it remains the same. The basic rule applies: you should get a torque converter built to your specific combination and intentions so the stall speed is correct.
After doing some research, we found the ATI StreetMaster torque converter with a single disk lock-up, and it fit the bill perfectly, so we made the call to pick one up. If you go into a higher stall speed range, the car has the ability to produce better elapsed times, however, it will start to generate a lot more heat on the street and lose some drivability. If your car has a bigger camshaft and rearend gear, that will only amplify the drivability issues for street use.
The billet-faced ATI StreetMaster converter was the perfect choice for the Red Dragon due to its dual purpose use of street driving and track duty.
Caine further explains what can happen with too big of a stall speed on the street for a torque converter. Too much stall and people tend to short shift, leaving them in high gear at 20 mph and making the converter do all the work; this is a bad scenario.
We have the experience to help you get the best performance from your vehicle. Start New Search. We could not find a converter for your selection - let's try an alternate search. Torque Converter - Stall Speed Fact: To get the best performance out of your vehicle you should tune the torque converter stall speed to the power curve of your engine.
0コメント