Wedge Adjustment

Wedge adjustment is a suspension tuning technique in motorsport where mechanics change the tension on rear springs to alter how weight is distributed across the car's tires, directly affecting how the vehicle handles during turns.

Think of your car like a table with four legs - when you adjust one corner, it affects the others. In wedge adjustment, changing the spring tension at one rear corner shifts weight diagonally across the car. For example, tightening the left-rear spring puts more weight on both the left-rear and right-front tires while reducing weight on the other two corners.

This weight redistribution is crucial because tires with more weight pressing down on them typically have better grip on the track. By moving weight around, teams can fix handling problems that drivers experience during a race.

When a driver reports that their car feels "loose" - meaning the rear end wants to slide out in turns - the crew will add wedge by increasing spring tension. This gives the rear tires more grip and makes the car more stable. Conversely, if the car feels "tight" or doesn't want to turn easily, removing wedge helps the rear end rotate better through corners.

The actual adjustment happens during pit stops when a crew member uses a special wrench inserted through the rear window. They turn a screw that raises or lowers the spring mount, changing how much the spring is compressed. Teams often measure these changes in "rounds" - full 360-degree turns of the adjustment screw.

Wedge adjustments are most common in NASCAR and other stock car racing series, where teams constantly fine-tune their cars' handling as track conditions change throughout a race. As the track surface heats up or cools down, or as rubber builds up on the racing line, what felt perfect at the start of the race might need adjustment to maintain optimal performance.