allows the engine to rev higher before locking up to get the engine up into its power band for a better launch. if your engine makes power from 2000 to 5500, you would probably look for a stall around 2500-3000 rpm. stall is the point at which the converter locks internally & has minimal slippage. a "higher stall" converter.
it keeps the engine from completely engaging until that rpm. normal stop and go driving will feel like your riding the clutch in a stickshift. dont go too high for a daily driver. also takes less brake to sit stopped in gear. they are usually built stronger than a stock torque converter as well.
The torque converter connects the auto trans to the engine. It is located inside the bell housing between the trans and engine. Simply it transfers the power & torque from the engine to the trans
Here's another version for you. It makes possible the automatic shift free operation of driving the car and letting the transmission do the shifting. The converter is a large fluid filled turbine bladed assembly. The engine turns one turbine and causes the other half to turn thru the fluid. There becomes a point that the input speed from the engine and the transmission side turbines match in speed. This is called lockup (but still has a small amount of slip) at all times unless it is a 'hard lock' assembly type transmission. These converters can be modified to change the 'lockup point' RPM and allows the engine to RPM higher into it's power band. This results in more torque being applied thru the transmission to the road, moving the car quicker. The converter location is just behind the light metal flywheel and ahead of the transmission. It splines onto the transmission input shaft and is bolted to the flywheel. The turbine assembly is internal and become filled with transmission fluid at the time the transmission is filled. It's physical size can be anywhere from the stock 12" diameter to a smaller sizes for hi power racing use with very hi stall speeds.
Just adding some info to already great input. A converter will likley not share the same slip from one engine/car combo to the next. Weight, engine power, gears all make it slip different. In first gear you will likely not feel the slip as much. In drive cruising at idle up till about 40mph you should feel the most slippage. Takes a while to get used to. If you are not running a mild build car i would suggest a 2500rpm stall or less. Strong street/strip 3000rpm to 3500rpm. Race only 4k and up. That is a broad application guess there. Consult a specialist. I use Coan converters.
The term 'stall converter' is not a proper term to use because it does not "discribe" anything specific. Torque converter is the proper term, then a specification in reference to it. Example: Hi stall is in reference to a stock unit's stall as referenced to a stock engine and car/truck application. There are a number of reference frames to use when talking about converters. A stock converter used behind the same engine but modified to a higher torque and rpm level, will cause the stock converter to have a higher stall rpm but still not be the best for the modified engine application. Also the rear gear ratio has an effect on stall even in a stock application. You have to reference back to the fluid coupling between the turbine halves. When there is more torque applied to this section the lockup goes higher before general lockup ocurrs. What happens is the fluid can only transmit just so much torque between the halves by turbine design before both are turning at nearly the same speed. During this time, the "fluid shear" causes a lot of heat to be generated making an external cooler manditory or the limits of the fluid will be reached where fluid break-down ocurrs. You may hear terms like 'flash stall' and 'brake' stall. These are variations of lockup under different conditions and can ocurr at different RPM points. As a point of reference for you, a stock converter begins to move the car at about 1400 rpm +/- but that is not the stall point. To get (close) to the unit's stall point under normal use, an accurate tachometer needs to be viewed as flash stall application is done. This stall level is more closly related to what the converter will do while running at light load cruise and not under power stall conditions. You can see from this that there are a number of different ways of specifiying converter performance.
