The driveshaft is the key link in any race car that transfers power to the ground. You can search the internet for "driveshaft breaking" to find many videos of cars breaking them, as well as still photos of driveshaft with pretzel shapes. Over-revving can also cause severe engine damage.
When choosing a driveshaft, there are many things to consider. These include the type and thickness of the shaft, the length, and yokes as well as U-joints which are appropriately rated for the job at hand. You should also consider horsepower and vehicle weight. You can also check out here to get more information about the racing driveshaft.
Image Source: Google
A heavier car with a stock frame will place more strain on the driveshaft than one with a tube chassis. Critical-speed ratings are an important metric for assessing a shaft's potential. This is when the shaft's frequency matches the rotation speed of its driveshaft.
If they are in sync, vibrations multiply and the shaft can enter "jump rope mode", which can cause the shaft to shake until it reaches the point of driveshaft failure. The critical speed of a shaft is determined by its length, diameter, and weight-to-material stiffness.
A longer shaft will produce a lower frequency, just like a wind-chime. Another consideration when choosing a driveshaft to fit your race car is the SFI 43.1 specifications. Many racing associations require that fast cars like Pro Mod and Pro Stock be used.
Driveshafts must meet SFI 43.1 specifications. Other components of the driveline, such as clutches and flywheels, flexplates, and transmission cases, are also subject to SFI 43.1 specifications. SFI certification is also required for these components. This is a way to ensure racer safety.