How does a torque converter work?

[crazychevyc10]

I was wondering if someone can explain how a torque converter works? If I'm shopping for one what should I be looking for? How does the stall benefit me?

Thanks!

[TBONE1964]

Originally Posted by crazychevyc10

I was wondering if someone can explain how a torque converter works? If I'm shopping for one what should I be looking for? How does the stall benefit me?

Thanks!

http://en.wikipedia.org/wiki/Torque_converter

This will explain everything. You will want to look for a company that has a good reputation building them to last without failure such as B&M or Coan.

If you contact one of the major camshaft manufactures, they can tell you which stall speed is best for your combination. It will be based on your vehicle weight, rear end gear ratio, tire size, cam shaft as well as horse power and torque of your engine. Some will have opinions based on their own experience.

Hope this helps
Tom

[Fitz]

Originally Posted by crazychevyc10

I was wondering if someone can explain how a torque converter works? If I'm shopping for one what should I be looking for? How does the stall benefit me?

Thanks!

Unless you are racing stall speed doesn't do much for you. Most stock trucks do not perform better with a stall above 1600 RPM. If you are a drag racer, it's a different story. Locking the brakes and increasing the accelerator pedal pressure until the rear wheels just begin to spin is the 'stall speed' of your converter. Increasing the stall speed to match the rising edge of the engine's torque curve allows for a launch near the beginning of the power curve of your engine, which is set by the cam you are using. The torque of my engine reaches 620 ft lbs at 2800 RPM so my torque converter has a 2800 RPM stall speed.

If you shop for one, look for a builder that has a good reputation like JW Performance, B&M etc. I've run Johnny Winters converters for a very long time. None better and he will rebuild it if it fails. If you want more info go here:

http://www.dragracingonline.com/tech...wtorque_1.html

[crazychevyc10]

So it sounds like if i have a stock 350 theres no need to shop for a high performance torque converter? Or at least if im looking for performance thats definitely not the first upgrade right?

[Keith Seymore]

Originally Posted by crazychevyc10

So it sounds like if i have a stock 350 theres no need to shop for a high performance torque converter? Or at least if im looking for performance thats definitely not the first upgrade right?

Correct. Especially for street use.

If you will be doing timed competitions (ie, drag racing) then there is definitely measureable performance to be gained in the torque convertor.

K

[mrein3]

Originally Posted by crazychevyc10

I was wondering if someone can explain how a torque converter works? If I'm shopping for one what should I be looking for? How does the stall benefit me?

Thanks!

Originally Posted by TBONE1964

http://en.wikipedia.org/wiki/Torque_converter

This will explain everything. You will want to look for a company that has a good reputation building them to last without failure such as B&M or Coan.

If you contact one of the major camshaft manufactures, they can tell you which stall speed is best for your combination. It will be based on your vehicle weight, rear end gear ratio, tire size, cam shaft as well as horse power and torque of your engine. Some will have opinions based on their own experience.

Hope this helps
Tom

I didn't read the wiki link but let me explain it to you the way it was first explained to me.
Think of two fans. One plugged in and power on, blowing at the 2nd one. The 2nd one turns from the air forced across it from the first one.

In your car/truck, the first one is coupled to the crank shaft on your engine. The second one is coupled to the drive shaft. Instead of air between the two "fans" you have hydraulic fluid - or transmission fluid.

Manufacturers can design them such that they slip - don't cause the drive shaft to turn - at a higher speed.

For racing guys you can take an engine that produces more torque at a higher rpm, put a high stall speed torque converter in it, buzz it up higher at the line, then take off in your engine's power band.

If you want better fuel economy, you want the lowest stall speed you can live with.

Also all the energy has to go some place. In high stall speed converters that energy is converted to heat in the transmission fluid. If you're running around town in a vehicle with a high stall speed you need all kinds of extra transmission cooling to keep that heat from destroying your tranny.

[Keith Seymore]

Originally Posted by mrein3

I didn't read the wiki link but let me explain it to you the way it was first explained to me.
Think of two fans. One plugged in and power on, blowing at the 2nd one. The 2nd one turns from the air forced across it from the first one.

Good analogy. The only thing I would add is that there is another element between the two, called a "stator", which also helps with torque multiplication.

K

[Fldawg]

unless your running a really choppy cam you don't need one , my cam called for a 2200 to 2500 stall, it helps when sitting at redlights cam sounds good but my truck is not shaking bad

[Bigdav160]

The torque converter's "stall speed" should be tailored to take advantage of the power band of the camshaft.