this is probably going to sound dumb to some people but what exactly is stall when it comes to torque converters?? like whats the difference between a 2000rpm stall and a 3000 rpm stall?

 

I probably cant explain it in the most technical of terms, but it has to do alot with torque multiplication. A torque converter is basically a replacement for a clutch with an interesting design. If you compared the same car with the two different transmissions, under controlled circumstances, the auto car with the torque converter will appear to have an "exponential" type of graph for torque, and it will seem higher. This is because of the torque converter.

Think of it in terms of a bicycle. When you go uphill, you need alot of torque/power to pedal up the hill, so instead of 24th speed, you are prolly gonna bring it down to 1st speed. You will have to pedal many times (rpm) to move just a little bit (speed).

Same bike, if you are going down a hill, you wont need much torque at all, but you can get lots of speed if you switch up to a higher speed. Less pedals (rpms) for a much faster movement (speed).

In both cases, you are providing the power, so its the same amount of power, but in first gear you are working with ALOT less effort than in 24th gear. If youve ever raced a freind on a bike, you start in first not in final gear right? And this is why....

Since an engine is capable of spinning very fast, and transmissions can make up for the speed, drag racers use this concept to their advantage. They use a higher stall (say 3000rpm) to get that torque multiplication off the line. In other words, the faster the engine spins at a given speed, the more torque or power it will put out. In a dragster's case, the higher the engine can spin before the wheels start spinning, the more power it will get to the ground.

However, not everyone drag races, and you dont want your engine spinning up to 3000 rpms, if you are travelling in a 20mph zone, so manufacturers use more gas freindly stall speeds. 900-1200 lets say.

If your looking to choose torque converter, it must be matched the most with what cam you are running. The converter has to be matched with what the motor is built for, and is putting out. So if you motor produces power from 4000-7000 rpms, you wanna start with a 4-4.5k rpm stall, rather than a 2000.

Im not exactly sure what the "stall" refers to, but if you held the brake slightly and revved up your motor, it will get to a certain rpm before it starts moving, your stall speed is roughly that rpm.

Hope that helps.

 

The stall speed is the speed at which the load applied to the engine by the torque converter with its output stalled equals the power output by the engine, preventing it from turning faster.

 

That's probably the simplest answer. Go read this. It's all about torque converters.

http://www.hardtail.com/techtips/torqueconverters.html

When you're done that rear this about how to select a converter

http://www.hardtail.com/techtips/sel...converter.html

The only way to know a converters true stall speed is with a transbrake. My converter stalls at 6000 rpm when I'm off the 2 step but I can still pop the tranny into first or reverse to easily drive it in or out of the garage. At the slower speeds, the converter is just slipping more.

 

Right you are, Stephen. On a 3000 rpm stall converter, lets say, you DO NOT have to rev the engine to 3000 rpms before the car starts moving. However, below 3000 rpms the converter is changing more of the engines production into slippage and heat instead of into movement. Above 3000 rpms, the converter is more efficient, and allows more of the engines power to the drive wheels. Another way to look at it is with a manual trans car. A 3000 rpm stall converter is identical to revving up your engine to 3000 rpms and then releasing the clutch.
Make sense now?