The NHRA Pro Stock cars you see on the track are amazing machines. Every single component has been hyper-optimized for the purpose of covering a quarter mile as quickly as possible. One of the most important parts is the car’s clutch, and it gets specialized service after each run.

Once the clutch is removed from the car, the discs are placed on a cutting machine that makes a series of cuts on each disc. The goal is to knock the glaze off each disc, and they get three passes on the machine. This makes sure the clutch will grab when the driver lets off of the pedal. The amount taken off is very small during each cut; this is done to make sure the disc will have plenty of life.

A Pro Stock car will use the same clutch pack for the entire weekend, unlike a nitro car that gets a fresh clutch pack after each run. The thickness of each disc is measured and recorded to track how much wear is occurring. This helps the team track not only how much life is left in a disc, but also gives them an idea of what kind of clutch adjustments they might need to make based on the track conditions.

In this video, Kelly Murphy from Elite Motorsports walks us through what goes into cutting the clutch of an NHRA Pro Stocker after each round of racing. You get to see the process he goes through to set up the clutch cutting machine, what he looks for when cutting discs, and how this process impacts the car’s performance.