Choosing A Driveshaft That Offers The Best Performance

21 September 2017
 Categories: Automotive, Blog

If you have recently purchased a sports car or an older classic vehicle that you intend on overhauling, then you may want to make sure that the parts used during the rebuild are ones that can enhance the performance of your car. When it comes to the driveline or drivetrain, the driveshaft is often overlooked. However, there are some things that you should look at closely to make sure you have the right driveshaft.


To understand driveshaft balance and why it is important in terms of performance, you need to look at the basic way that the drivetrain works. In the most basic sense, the driveshaft is the part of the drivetrain that moves energy from the transmission, to the differential, and then to the wheels of the vehicle. Without the driveshaft, your vehicle would not have the horsepower it needs. While it is true that the driveshaft does not directly affect horsepower, horsepower can be lost due to the way that the driveshaft spins. The most horsepower is lost if the shaft is not balanced, since it can and will vibrate.

Most driveshafts are balanced at a specific RPM. This means that it can sustain a direct transfer of horsepower when revolving at a specific speed. Once the shaft spins beyond this speed, it will start to vibrate. This is called a transverse vibration, and it is the same one that you may notice if the shaft is unbalanced. 

Most driveshafts will be balanced at an RPM that is consistent with normal driving speeds. For example, the balancing may allow the vehicle to retain horsepower without loss while going under 100 miles per hour. However, if you want to race your car on a track or push the vehicle to its limit on a test drive, then a driveshaft that has undergone a high-speed balance is a better choice. High-speed balancing will involve some angling of the driveshaft, since a decreased angle can help to increase stability at higher RPMs. If you want to know how the angle can affect your driveshaft, use an RPM calculator

Length and Material

While balancing is important and essential to the function of the shaft, you need to make sure that the driveshaft you choose is capable of spinning at a higher RPM. Specifically, you need to choose the shaft made at the right length and made from a proper material. When it comes to length, a shorter shaft can spin more quickly without vibrating. Keep in mind that a shorter driveshaft will require the use of a longer axle shaft or axle attachment. 

The material can change the speed of the shaft and how it transports energy through the drivetrain. Carbon fiber driveshafts can spin the fastest without failure. However, carbon fiber parts are typically used on professional race cars and other high-performance vehicles. While they can be used with hobby cars and classic vehicles, the parts are extremely expensive. They also likely need to be custom ordered, and this can increase your expenses considerably.

If you do not want to spend as much money, then an aluminum driveshaft is a good option. While aluminum is not stronger than steel, its lighter weight allows for higher RPM rates. Steel and chromoly have the lowest RPMs and will fail more quickly. However, if you purchase a shaft that is thicker, then this can reduce vibration concerns. Since steel driveshafts are the most common, you can typically find these shafts in a wide variety of different lengths and diameters. 

If you want to know more about drivetrains and the different parts that are available to you, then speak with a company like Godfrey Brake Service & Supply.