Full Answer
What RPM does the torque converter stall at?
At the track the converter stalls at approximately 3,500 rpm, for excellent drag-strip runs. The converter is locked nearly solid above the stall speed, and has been in service for many years, without any additional transmission cooling required.
What is inside a torque converter?
Torque converters come from the factory welded up, so its pretty hard to get a look inside and see what makes them tick. From the right counter-clockwise, you can see the cover (which bolts to the flexplate), the impeller pump (which slides over the transmission input shaft) the turbine, and the stator.
Do you need a torque converter for a big block engine?
High-torque big-block engines, or even large-displacement small-block engines, should use converters closely matched to their power output at lower engine speeds. Don’t install a converter that is too loose with a street RPM engine. Otherwise, you’ll run out of RPM much too early in the quarter-mile.
Does horsepower affect a torque converter size?
When we initially began to do the research for this article, we had conventional wisdom in mind – the less horsepower a car makes, the smaller dimensionally the torque converter can be, but as we covered the topic with our four specialists, we discovered that wasn’t necessarily the case.
What size is a stock torque converter?
Converter Size Typically, the 8-inch converter (depending on internal fin angle and the style of stator), will most likely flash stall at a much higher RPM than the 10-inch competition unit.
What stall torque converter do I need?
For mild performance cars with something like a 350 HP engine, a 2,200 - 2,400 stall is about right. The basic rule of thumb is; if your engine "comes alive" at say, 3,500 RPM, then you want a stall converter with about 3,500 of stall to it.
What is the stall speed of a stock torque converter?
around 1,800-2,000 rpmStock torque converters generally have a stall speed around 1,800-2,000 rpm. Higher stall speeds become necessary when horsepower and torque happen at higher rpm ranges.
How can I tell what torque converter I have?
There are two main types of industrial torque converters....Identification - Torque ConvertersIdentifying Marks – any numbers, letters, paint stripes, paint dots, etc. ... Hub - the portion of the converter that is inserted into the pump and is located on the transmission side of the converter.More items...
What does a 2500 stall converter do?
A 2,500 stall speed doesn't mean you need to rev the motor to 2,500 rpm for the vehicle to move." What it does mean in this case is 2,500 rpm is the limit at which the converter will hold back the engine speed if transmission output is prohibited.
Do you need high stall torque converter?
A higher stall torque converter will let your car accelerate better because the car will be taking off at the rpm range where it is making the most power. But you don't want a stall speed that is too high either.
What does a smaller torque converter do?
Larger-diameter converters are usually more efficient and deliver less slippage, while smaller-diameter converters offer more stall speed and more slippage. Vehicle weight is another major factor that should be considered when selecting a converter.
What does a low stall torque converter do?
With a responsive turbo (especially the newer VGT models), a low-stall converter will deliver more power to the rear wheels and create less heat without lockup.
How do I know what stall converter I have?
0:301:38TCI® Quick Tech: How To Properly Measure Converter Stall - YouTubeYouTubeStart of suggested clipEnd of suggested clipHowever the more accurate way to check converter stall is by flash stall to determine flash styleMoreHowever the more accurate way to check converter stall is by flash stall to determine flash style floor the throttle from a dead stop at idle look at the tachometer.
How do I identify a Chevy torque converter?
6:149:42How to ID Chevy Transmission TH350 Torque Converter TH400 TH250YouTubeStart of suggested clipEnd of suggested clipAnd you can see by the angle. And this divots look like whether this is the 1211 stall the 1611 toMoreAnd you can see by the angle. And this divots look like whether this is the 1211 stall the 1611 to 2025 stall or the 1397 stall.
Are GM torque converters interchangeable?
GM FWD Torque Converters All 125-C, 440-T4, 4T60, and 4T60-E transmissions use the same style torque converter, and they are interchangeable before 1996.
What is the stock stall on a 4l60e torque converter?
1,650 rpmThe stock torque converter has a stall speed of 1,650 rpm.
What are the parts of a converter?
There are four main parts to a converter – the turbine, the pump, the stator, and the front cover. The cover is the part that bolts to the engine (via the flexplate) and has the pump welded to it externally.
How does a stator work?
The fluid flows through the center of the stator, which also has angled fins on it, and back into the pump. The stator has a one-way clutch inside it that allows the fluid to turn it only in one direction, which is the direction it needs to reverse the fluid angle as it flows back towards the pump.
What size converter for a supercharged X275?
For example, Reed says, “In a supercharged X275 car, the converter will typically be a 10-inch size, but a turbocharged car might use a 9.5-inch converter.
What is the part that connects to the input shaft of the transmission and turns independent of the engine?
Opposite the pump is the turbine, which is the part that actually connects to the input shaft of the transmission and turns independent of the engine. The pump hub, which is welded to the pump cover, engages the pump in the transmission.
How does a torque converter work?
A torque converter has the impeller connected to the engine , while the turbine is connected to the mechanical portion of the transmission. Upon engine startup, the transmission oil pump pressurizes the converter with ATF. The impeller throws the ATF into bucket-like receptacles of the turbine and generates some pressure on the turbine in the same direction as the impeller is turning. After striking the turbine, the ATF is deflected back toward the impeller. As the engine speed increases, additional ATF velocity develops due to impeller action, and without a stator installed, the ATF would be reflected back from the turbine to the impeller in a direction that impedes the impeller operation. With a stator installed, the stator vanes redirect the returning ATF so that it strikes the impeller elements in the correct direction.
When was the first torque converter invented?
The first automotive torque converter was tested in the 1920s in Germany, and torque converters were used in railcars in the 1930s. Later, a truck was produced in Sweden in the 1930s with a torque converter.
What is a stator clutch?
The stator contains a roller oneway clutch, similar to what is used inside the transmission for the low/reverse clutch. The inside splined portion of the one-way clutch is engaged in the front of the transmission’s stator shaft. At low engine speeds, the one-way clutch is on and holding.
Why lock and unlock torque converter clutch?
They could lock and unlock the torque-converter clutch when needed to provide torque multiplication for improved vehicle acceleration, such as passing maneuvers, then apply the converter clutch for maximum power transfer and efficiency for light-throttle operation at highway speeds.
Why did they add a clutch to the transmission?
To eliminate torque multiplication at higher vehicle speeds, a clutch was added to the torque converter on the 700-R4 and 4L60 transmissions. This provided a direct 1:1 drive between the engine’s flywheel and the transmission’s input shaft.
What is ATF coupling?
The fluid coupling operates similarly to the fan example, except that ATF (automatic transmission fluid), rather than air, is the medium used to transfer power. The ATF for the fluid coupling (and torque converters) is furnished by the automatic-transmission gear-type oil pump. Both halves of a fluid coupling are constructed identically ...
What transmission did Buick use?
The 1949 Packard was next with a true torque-converter transmission , called the Ultramatic.
What is the job of a torque converter?
The Basics. When using an automatic transmission, it’s the torque converter’s job to transmit and multiply the engine torque, and deliver it to the transmission. If you cut open a race torque converter, inside you will find: the turbine, stator with sprag, and impeller pump. The converter’s turbine is attached to the drivetrain via ...
What is a stator?
The stator is the fluid director and changes fluid flow between the turbine and pump. It is what makes a torque converter a torque multiplier, and not strictly a fluid coupler. Remove the stator, and a torque converter will retain none of its torque multiplying capabilities. For the stator to properly function, the sprag (a mechanical, ...
What is stall speed?
When someone talks about stall speed, they are talking about how many RPM the engine can attain with the transmission in gear and the car’s brakes applied — before the drive wheel (s) spin. When discussing street-use torque converters, stall speed is typically listed as a range (example: 2,500 to 3,500 rpm). The range listed will tell you what you can expect from the converter. If a 2,500 to 3,500 stall speed is selected, you should be able to hold the brakes (footbrake), and the converter should allow the engine to rev to around 2,700 to 3,200 rpm. Of course, this is dependent on the vehicle’s setup. Dallas Moss at TCI Automotive helps us understand how.
How does weight affect foot brake stall?
Vehicle Weight. The vehicle’s weight affects footbrake stall, by giving the converter more load to move. The heavier the vehicle, the higher it will push the stall of the converter. Of course, the opposite is true of lighter-weight vehicles.
Why does a 3.08 gear stall?
This one is relatively straightforward, the lower numerical-value gears, such as a 2.73 or 3.08 gear, the higher the converter will stall because it’s taking more force to move the vehicle.
Can a torque converter fit all?
When it comes to choosing a torque converter, one size certainly doesn’t fit all. All of the major torque converter companies employ skilled personnel that have a wealth of information available. But, that information is useless if you do not provide accurate information about your car and its components.
Is it possible to choose the right torque converter?
Let’s face it, unless you have a lot of experience with torque converters, it’s nearly impossible to choose the correct one for any given application and predict with certainty how it will work in the car. When looking at all of the options available, ...
