Driveshafts, or propshafts, and constant velocity (CV) joints are crucial to the proper and safe operation of a vehicle. They are necessary to move a car forward and make it turn. But what sort of equipment is needed for a race car?
In this video, Wyatt Knox and Tim O'Neil himself from Team O'Neil to give us the answers.
In the first part of the video, the duo talks about the affects of steering angle and wheel articulation as they relate to CV joints. A CV joint accepts a driveshaft and allows it to transmit power through varying angles of wheel articulation. As the transmission feeds power into the input shaft section, it's sent through a driveshaft to the output CV joint, which connects to the wheels through a spline to the hub.
As a race car adds more suspension travel, like a rally car might for instance (Team O'Neil's specialty), it puts greater stress on the CV joint due to greater angles where the axle enters the CV joint. Dialing in more steering angle furthers the problem by adding greater fore and aft angles on the CV joint as well. Both instances create more wear and tear on the CV joint. Another issue is the CV boot. If it is torn, the grease can get dirt in it and wear out the joint.
Parts can be swapped in to handle the needs of racing. Larger parts, either dedicated racing parts or parts from a car with more power, can handle a race car's additional power and the needs of the more dramatic angles encountered while rallying.
Wyatt and Tim talk about the various twisting and shock-loaded forces that act upon this area of a car. Simple changes such as stiffer engine mounts or a racing clutch instead of a stock clutch can cause more torment on CV joints and driveshafts. You may think you need all racing parts all the time, but a combination of stock and race-ready parts can lead to a car that's healthy and happy to rip down a trail.
Axles and CV joints may not be top of mind when building a rally car, but they are vital. Without proper CV joints and driveshafts, your day will be over quickly.