Cushion

The cushion is the ridge of loose dirt pushed to the outside of a dirt track by cars running laps. Drivers lean into it for extra bite, and it moves and shrinks all night.

Also called:

berm, the top

In practice

World of Outlaws defines it as “the loose dirt that is pushed up the track, toward the walls, as the cars make laps around the track.” NASCAR’s version adds that the cushion “will move up as cars run a higher line on the track throughout the event.” Running it is a real skill — you use the berm as a wall to lean the right side against, which lets you carry more speed than the racing surface alone will hold, but get it wrong and it will launch you into the fence. Two things to watch: a cushion that’s growing means the track still has material to give, and a cushion that’s disappearing means the surface is going slick and your setup needs to move with it.

Why it matters

The cushion is free grip if you can read it and a wrecked race car if you can't, and its condition tells you where the track is headed.

Go deeper

Read the full post:

Dirt Track Slick Setup: How to Chase a Track That's Going Away

Sources

Glossary — World of Outlaws — sanctioning body’s fan glossary defining the cushion as loose dirt pushed toward the wall by laps.
Dirt Racing Terminology, FAQ for Bristol Dirt Race — NASCAR — sanctioning body glossary noting the cushion moves up as cars run higher lines through an event.