A Flywheel? What Is A Flywheel? Learn What It Is And Why It Matters

When discussing driving performance, especially in manual transmission vehicles, the type of flywheel you have installed is going to come up.

What is a flywheel, and how does it affect the performance of your car? Keep reading for all you need to know about flywheels.

What is a Flywheel?

A flywheel is a circular metal disk that serves as the meeting point between your engine and your transmission. Its job is to transfer energy using the torque and horsepower created by your engine and to engage the gears inside your transmission. That energy is then processed by the gears of your transmission and applied to the axels, turning your vehicle’s wheels on the ground.

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This may sound complicated, but choosing an upgraded flywheel is a relatively simple way to improve your car’s performance. There are different weight and material options for you to choose from.

Flywheel Materials

There are different qualities of flywheels. Most flywheels are made out of steel and conventional bearings. These are usually in the heavy flywheel category. Most modern cars come standard with a steel flywheel.

For an upgrade, you can choose an aluminum flywheel. Aluminum is a lighter metal that has come to replace a lot of steel and iron components in vehicle manufacturing. It is lighter than steel but still very strong. 

Carbon Fiber Flywheels

Some of the best flywheels are made out of carbon fiber and use magnetic bearings. Carbon fiber is becoming very popular because of its strength and is the ultimate lightweight material. This is used most often in professional race car builds.

Carbon fiber flywheels are also the safest option for racing. In cases of malfunction at high speeds, steel flywheels can cause extra risk. They can become dislodged and tear through the vehicle during a crash. This can be very dangerous.

The carbon fiber material disintegrates under malfunction. This makes it a much safer option if you plan to take your car to high speeds and especially if you plan to use your vehicle on a racetrack.

However, carbon fiber can be exclusionary expensive and is really only an option if you plan to race professionally. 

How Does It Work?

In a vehicle with a manual transmission, rotational energy is applied from the crankshaft to the flywheel. The flywheel then applies that energy to the transmission using the clutch disk and splines. The amount of energy transferred by a flywheel is proportional to the square of its rotational speed.

The bigger the mass of the flywheel, the more momentum it can store. It is able to preserve the energy applied by the crankshaft by resisting changes to rotational speed. This is useful to save energy during deceleration and stopping.

The smaller lighter flywheels use more initial energy but are able to apply more horsepower to the transmission. 

There are different types of flywheels available for your vehicle. It is important to learn about them in order to determine which one best fits your needs.

Heavy Flywheel

Heavy flywheels are most commonly installed in everyday vehicles. They have higher momentum and are able to store more energy. They store more energy because they have a larger rotating mass. 

Heavy flywheels require the engine to do less work during initial takeoff. This helps compensate for lower-powered vehicles. They do not need as much horsepower and torque going to the crankshaft to send energy through the larger flywheel. 

The negative aspects of this type of flywheel are you lose more horsepower making it to your wheels. The more rotating mass the flywheel has, the more horsepower is lost turning it. It also causes the engine to build RPMs more slowly.

Lightweight Flywheel

Lightweight flywheels are marketed to consumers who are trying to get the most power out of their vehicles. They are ideal for vehicles that sport more power in general. It’s important to remember, your flywheel can only use the power it is given by your engine crankshaft’s performance ability. 

Lightweight flywheels have less rotating mass. They store less energy in the flywheel; therefore they require more torque from the engine. Higher RPMs are necessary at initial takeoff. 

They are able to transfer more horsepower after initial takeoff to the transmission and therefore to the wheels. You are loosing less power. Lightweight flywheels cause less parasitic drag in your powertrain. 

Symptoms of a Bad Flywheel

There are signs that its time to replace your flywheel. If you can feel vibrations coming from your clutch pedal, this is a sign that your flywheel needs to be replaced. 

A bad flywheel can also make it harder for your clutch to grab, which can cause slipping while shifting into higher gears. If this is happening, you will also notice a slight burning smell after you shift gears. 

Clutch chatter is also common on a flywheel that is defective. You will feel your clutch lurch and stutter as you are shifting gears. If this is happening, it’s time for a new flywheel.

Benefits of a Flywheel Upgrade

When choosing a lightweight quality flywheel, such as Fidanza Flywheel, you get torque and horsepower gains. You can expect faster throttle response and quicker acceleration. You will also notice more fuel efficiency. 

During driving, your engine will be able to free rev. This means it will be easier to get your engine to your desired RPM. This also helps with rev-matching on downshifts.

You are also able to shift in a faster, more efficient manner. Better flywheels also increase clutch holding capacity. 

Flywheels are also pretty inexpensive, costing just a few hundred dollars for one of good quality.

Your Flywheel is Important

Choosing the right flywheel for your manual transmission vehicle is essential to getting the performance out of it that you desire. Details such as changing out a heavy flywheel for a lightweight one can make a larger difference then you might have thought. 

If you want more information about other changes you can make to help your car go faster, check out some of our other blogs.

The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of SpeedwayMedia.com.


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