Having a firm grasp on how to properly tune the rear suspension of a vehicle at the drag strip is an easy path to quicker and more consistent elapsed times. There are numerous variables and factors to consider when looking at how you adjust a suspension and it’s easy to get lost in all of the information. This video from QA1 provides a quick explanation of rear shock tuning that every racer needs to see.
If you’re going to lay a solid foundation of understanding how to tune the rear shocks of your racecar you’ll need to become familiar with the concepts of rebound and compression. When you need to hit the track hard with the tire you’ll want to have the rebound on a softer setting, while a stiff setting will slow the shock rebound down so you’ll hit the tire softer. The compression setting of the shock is how you control the tire “bouncing” back up and keep it planted to the surface of the track. How stiff or soft you have the compression set will dictate the amount of movement the tire will have.
There are two main types of shocks that have adjustable rebound and compression settings. Single-adjustable shocks use only one knob to adjust both the rebound and compression of the shock at the same time. These shocks are designed for cars that see a lot of street driving and aren’t ideal for full race cars. Double adjustable shocks use two knobs that allow you to change the rebound and compression independently. These shocks are a must-have for high-horsepower race cars to help control how the tire interacts with the track.
Using a slow-motion video is critical when it comes to making proper shock adjustments. The slow-motion video will show you exactly how the tire and car are reacting when power is applied. You want to look at the initial movement of the car to see how much separation is happening and how the tire is reacting to the shock setting. The type of track and tire will also play into how you adjust shock settings, based on how much separation you see.
Make sure to watch this entire video hosted by Steve Smith from QA1 so you can learn more about tuning the separation of the suspension by adjusting the compression and rebound of the shocks.