Lightweight flywheel: features, device, advantages and disadvantages

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

One of the main elements of the engine is the flywheel. It is to him that the torque is transmitted from the torque shaft. The element is connected to the box through the clutch disc. It is one of the most expensive parts in the crank mechanism. What is this element and what does a lightweight flywheel give? Let's find out.

Function

As we said earlier, the flywheel is an integral part of the crank mechanism.

Item intended for:

• To reduce uneven rotation of the crankshaft.
• Transmission of torque from the internal combustion engine to the transmission (the flywheel is the clutch disc).

Smoothing of torque pulsations is achieved due to periodic feedback and accumulation of kinetic energy by the flywheel. It is stored during the working stroke of the piston. Energy is consumed during the piston withdrawal stroke of their dead center. The stroke of the pistons increases with the number of cylinders in the block. And in order to ensure an even transmission of torque, indesign includes a flywheel. The lightweight element differs from the factory one primarily in mass (more on that later). But, regardless of the type, this mechanism is fixed in the end part of the crankshaft, at the rear main bearing. The latter is highly resistant to stress. It is the main bearing that bears the weight of the flywheel and all the loads from it.

About the mass

If we consider the elements of ordinary passenger cars, their weight will be from 7 to 9 kilograms.

A lightweight flywheel weighs about 5. But there are models whose weight is 4 kilograms or less. As a rule, these are thin elements made of aluminum alloy.

What is the relevance of a heavy factory flywheel?

This element provides stability at low engine speeds. This greatly helps beginners at the start - the car starts off as smoothly as possible. If we consider a lightweight flywheel, the car will move very sharply with it.

The factory element also makes it possible to start from higher gears. There are often cases in the city when you need to move right away. The car has gained 5-10 kilometers per hour "freewheeling", and you need to continue moving further. It will be difficult to turn on the first speed - you will either break the synchronizers, or not stick it at all (all this is accompanied by a characteristic crunch). Therefore, the best option is to use the second gear. Due to the heavy mass, the factory flywheel can provide good torque from the bottom. This is a big plus.

Why put light?

It would seem, why get into the design of the engine and change something, if the regular flywheel normally copes with its task. But it is worth noting the main drawback of the factory element. Due to its huge mass, it greatly slows down the acceleration of the car. The motor needs to make more efforts in order to unwind such an element to the desired parameters. A similar picture is observed with the installation of disks of large diameters. No matter how strange it may seem, but the dynamics on such wheels are inferior to those measured on regular casting (smaller diameter - less weight).

Thus, a lightweight flywheel will unlock the full potential of the engine. It will be easier for the crankshaft to rotate it. Accordingly, the acceleration dynamics will increase. For this purpose, a lightweight flywheel is installed on the VAZ-2101 and other cars. But why is such an element not installed immediately, from the factory? This flywheel has a number of disadvantages. We will talk about them below.

Cons of a lightweight flywheel

Why do manufacturers themselves not use such a flywheel when assembling engines? Yes, it is very easy to pick up speed with it. But just as easily, it is lost due to its low mass. The fuel consumption of the car also increases significantly. There is a drop in engine speed before shifting into high gear. If you do not turn on the speed quickly, you will have to go at a reduced speed again. Because of this, the box is constantly loaded. To save its resource, it is recommended to pause between gear changes (at least two seconds). FROMlightened flywheel during this time, the speed will drop almost to idle. The box will have to be constantly “raped” in order to move around the city normally.

What are the pros and cons of a lightweight flywheel? This element will not allow you to smoothly start from a place. No matter how hard you try to slowly release the clutch, there will be a characteristic push. On long distances, the driver is forced to constantly give gas.

Test results have shown that such a flywheel allows you to gain momentum faster. But at the same time, the torque itself drops, the value of which is so important when accelerating. In view of this, the driver will have to constantly keep the engine at high speeds. This can provoke increased wear of KShM parts, not to mention oil consumption. The motor itself should be running within the green scale. If you install a light flywheel, the arrow will be close to the cutoff. And it will happen so fast that you won't even notice it.

Cost

Usually the owners of domestic cars are engaged in the installation of these elements. Now there are a lot of shops selling ready-made, lightweight flywheels. Their mass is about 3.9 kilograms for a one and a half liter engine.

What is the price for a lightweight VAZ flywheel? The cost of sports elements starts from 2, 2 thousand rubles (for VAZs of the "tenth" family). There are also ready-made kits for "Zhiguli" classic models. For example, in the SovietA "penny" lightweight flywheel costs 2,65 thousand rubles. The most expensive flywheel is for the VAZ-2181 cable box. Its price is 2.9 thousand rubles. Lightweight flywheels for Niva (including Chevrolet) are also on sale. But experienced motorists say that this part is completely useless on an SUV. Such cars, on the contrary, should have good torque. Especially if this car is prepared for offroad.

Can I lighten the factory?

There is also an option to lighten the factory flywheel (although the cost is almost the same as a new sports element). This is done by removing an excess layer of metal from the surface of the disc. When grinding, the mass of the VAZ flywheel decreases from 7.5 to 4 or less kilograms. But whether such action is worth taking remains a big question. If you don't compete in motor racing, chances are you don't need it. It makes no sense to install a lightweight flywheel on a civilian car. Your fuel consumption will instantly increase.

You will have to constantly keep the gas in the floor. In this case, there will be sharp gear changes. It will be uncomfortable to use such a car for commuting.

Conclusion

The lighter flywheel is a very good development in motorsport. But putting it on a civilian car does not make sense. Such a flywheel has a number of disadvantages that are very difficult to put up with.