How IMSA Driver Stint Rules Work and Why They Reshuffle Results

Mandatory Stint Requirements

In multi-driver sports car racing, sporting regulations prevent teams from leaving their fastest professional behind the wheel for an entire event. Under IMSA rules such as Standard Sporting Regulation 12.13.2, entries must distribute track time across their lineup based on driver ratings. Silver- and bronze-rated drivers are assigned a specific minimum drive-time, while every other co-driver must hit an established base drive-time outlined in the event regulations. If a red flag halts the race, rules dictate that these mandatory thresholds are reduced proportionally to match the track time lost.

Enforcement and Classification Demotions

Officials verify compliance through post-race audits of official timing and scoring data rather than immediate on-track penalties. Under Article 12.12, violating IMSA minimum drive time penalties drops a car behind every finishing competitor in its class that met the regulations, effectively placing the entry at the back of the class order regardless of where it crossed the finish line. Because these audits occur after the checkered flag, sanctions often overturn provisional podiums and race wins, such as at the 2018 Canadian Tire Motorsport Park round where Kyle Masson lost a provisional victory after missing a mandatory 40-minute stint requirement.

Official reference: IMSA Announces Drive-Time Penalties From Rolex 24 | IMSA.