We will try to keep this short since high stall torque converters is a long subject. When the torque converter locks up while it’s under load, this is called “stalling.” Say you have a car with a stall converter that goes down to 2,500 RPM. If you hold down both the gas and brake pedals at the same time, as if you were going to power brake, the tires will generally come loose at 2,500 RPM. The converter would come loose at 3,500 RPM if it has a stall speed of that speed. Keep in mind that if the same type of converter is in a big block and a heavy or very good-traction car, the torque will push the stall speed up to a higher RPM. On the other hand, if the engine has less power, it will do the opposite and the converter won’t stall out as high. The weight, torque, and traction are all to blame. To find the exact RPM stall, it’s not an exact science.
Stock gearboxes for torque
The stall speeds for most stock cars will be between 1,000 and 1,400 RPM. It’s simple to understand how a stall converter works. At 1200 RPM, an engine has only about 80 horsepower. At 2500 RPM, it could have up to 200HP. A car with 200HP will obviously be easier to start than one with 80HP. Many high-performance engines don’t have good horsepower until around 3000 RPM. That’s why, if you have a higher-HP engine with a big cam, you will need a higher stall speed so that it starts off closer to the power band. If you don’t, it will fail and start out slowly.
What Does “High Stall” Really Mean?
Some people think that stalling means the car won’t move until the engine reaches a certain RPM. This isn’t the case. When the car is in gear and the brake is off, it will idle at about 10 MPH, just like any other car in gear with the brake off. When you cruise into the pits, you usually leave the car in gear and let it idle. A 6000 RPM converter doesn’t mean that the car moves until that RPM. If it did, the engine would have to be turned all the way up to 15 MPH, which isn’t how it works. When the car is on the start line, the trans brake is on, and you hit full throttle, the engine will rev up to 4500 RPM while the car is still. This means that when you take your finger off the trans brake and the tranny comes out of reverse, the car will launch at 4500 RPM. At that RPM, a race motor is close to hitting the peak torque curve when it leaves the line, which is why you get big wheelies or low 60ft times when the grip is good. If the engine is too rough, the stall speed will need to be higher because the engine won’t have any power at low RPM and won’t have enough torque. Things like weight, torque, gear ratio, and cubic inches play a role in this. This won’t get the flash effect when the stall converter flashes to when you take your finger off the trans brake. Once the car is moving, a normal 3000 RPM converter can flash up to about 5000 RPM. I’ll keep it simple because the process is pretty hard to understand.
Cars and trucks that need high-stall torque converters
If you put a 6000 RPM converter behind a stock engine, the engine might not be able to reach that speed because the load converter will stop it. Low RPM means the car will roll, and it might never get to 6000 RPM. For a 3000 RPM converter, this is true. Most mild race cars will use stall speeds of around 3500 to 4500 mph. A faster car will usually have a higher stall speed, especially if the engine is smaller and doesn’t have a lot of torque. Also, the hydraulic fluid inside the converter will make more heat when the stall speed is high. A high stall converter can usually make enough heat to damage a transmission if you keep the line open for too long at full RPM if the stall speed is above 3500RPM. If you have a high stall converter, you should get a granny cooler.
A lot of high-performance street cars will have a normal performance cam, which should have a stall converter between 2800 and 3000 RPM. If your car is hot and has bigger cams, a 3500 RPM converter is better. A stall speed of 2400 RPM is best for a car with a 350HP engine. If the engine starts at 3500 RPM, you should get a converter that stops at about 3500 RPM. A lot of people over-cam and carburete their cars, which is bad. They will get about 2000 RPM, which isn’t enough to get it off the starting line if you need a 3000 RPM stall. Don’t forget that the first 100 feet will make up 80% of the race. Not being able to get off the line means you will lose the race.
Road Runner Converters Offers Many Torque Converter Replacements
Road Runner Converters offers many torque converters for sale online. We offer GM Torque Converters, Ford Torque Converters, Diesel Torque Converters, Towing Torque Converters, Street Torque Converters and more.
