How Pinion Angle Affects Driveshaft Velocity

There is no doubt that the "proper" pinion angle is one of the most heavily debated topics there is with race cars! Typically debates rage about how pinon angle effects bite, how pinion angle can cause driveshaft vibration and/or U-joint problems, but rarely does the conversation SHOW you what goes on when your pinion angle is NOT parallel.

That's why this video is so awesome and I wanted to not only put a link up to it to share, but also so we can find it again! How much of the bite argument is due to the change in driveshaft velocity at increased angles? Will it depend on where the car launches at in relationship to the u-joint angle? This video will certainly make you scratch your head and think about these aspects of suspension tuning...

Pinion Movement without Traction Bars or Cal-Tracs

This vid is kinda long but it's a great example of what's going on just in regular stop light driving with a leaf spring suspension, you can imagine how bad this would be at the dragstrip without any kind of device to limit spring wrap up. After viewing the 1st video on driveshaft velocity, it's crazy to think what acceleration and deceleration the rear end is going through when those angles change!

Pinion Movement with Cal-Tracs

This is a decent example of a leaf spring cal-trac equiped car and how much better the leaf spring wrap and pinion angle change is compared to no traction device. Unfortunately we haven't found a video of a highpowered low teen 60'ing car with Cal-Tracs to see what's going on with a faster car, but maybe someone can make one soon to add to these examples. You'd have to assume on a higher HP car there will be a lot more deflection going on that in this video.