Differential height describes the height of the differential above the chassis.
The purpose of changing diff height is to keep the driveshafts close to level when the car is at its resting ride height. This helps minimize friction that develops in the driveshafts when they are operating at steep angles compared to level (in turns.)
Diff height is typically adjusted via inserts in the differential housing that allow the bearings that hold the differential to be moved up and down, but on some cars the entire gearbox is moved up and down.
Lower diff height
- Allows higher ride heights
- More stability in bumps
- Increases corner speed on open tracks
- Keeps axles level on low-grip tracks with higher ride heights
Higher diff height
- Better for jump landings
- Keeps axles level on high-grip tracks with lower ride heights