A new NASCAR rule change goes into action regarding chassis shims for 2023
In 2022, NASCAR launched the Next Gen car. The car is designed to be identical from team to team. However, within the rulebook, there’s wiggle room to make each car a little different.
Ahead of the 2023 season, NASCAR has adjusted the rulebook. In this case, it’s regarding shims that mount between clips on the front chassis section.
See the NASCAR chassis shims graphic below.
Previously, NASCAR allowed teams to make the shims up to .160″. That rule has been reduced to just .100″.
Brian Murphy of Stewart-Haas Racing explained, “Clip shims allow the teams to locate front/rear clips (X,Y,Z) during installation. Correct location has a multitude of affects on overall performance.”
He vouched for the rule change saying, “There’s a number of reasons including .160” just simply being an enormous amount.”
New NASCAR Rule
The rulebook now reads as:
“Shims may be used between each respective front sub-frame and center section assembly bulkhead mount. The shims must be constructed of magnetic steel.”
“The combined thickness of the shims on each respective bulkhead mount may be maximum of 0.100 inch.”
Shims must be manufactured to match the profile of the applicable CAD below:
NASCAR Chassis Shims
Photo
