iRacing Season 3 introduced series-specific pit stop rules. The differences between rulesets affect how long your stops take in races. iRacing Staff member Christian Challiner posted a quick reference guide on June 17. It breaks down which timing rules apply in which classes across the Season 3 lineup.
Also See
➡️ What Changed for GT3 in iRacing Season 3: The BoP Overhaul Explained
🏁 Official Season 3 Pit Stop Rules Reference (Christian Challiner, iRacing Staff)
The guide covers rulesets including IMSA, WEC, and several others, with specific timing differences for each. Cars and series not listed in the table follow the Default or Global ruleset. If your series does not appear in the reference, your pit stop timing has not changed from the previous standard.
For most of iRacing’s history, pit stop procedures were consistent across series. Season 3 changed that by tying pit lane rules directly to the real-world regulations of each sanctioning body. The intent is to make pit stops feel authentic to the series you are competing in. An IMSA endurance entry now follows IMSA procedures rather than a generic iRacing standard.
IMSA Ruleset
Under the IMSA ruleset, pit stops enforce a minimum time in the box regardless of what service is performed. This reflects real-world IMSA WeatherTech Championship regulations. A mandatory minimum stop duration prevents cars from taking a quick splash and returning to track before competitors can react. In iRacing’s IMSA-licensed series, pit strategy must account for that floor. You cannot shorten a stop beyond the minimum simply by requesting less service. The floor applies whether you take fuel only, change tires, or do both. Your stint calculations need to treat it as a fixed cost.
WEC Ruleset
The WEC ruleset applies to series modeled on FIA World Endurance Championship regulations. WEC-spec stops have their own timing structure tied to real-world rules used at Le Mans and other WEC rounds. Refueling rates and mandatory service requirements differ from IMSA. The calculation for a fuel-only stop versus a full-service stop works out differently under WEC. For iRacers competing in GTP or Le Mans-class series, understanding WEC timing before building a stint plan is essential. Build your fuel window around the expected service times, not a generic assumption carried over from a previous season.
Default and Global Ruleset
Series not listed in the reference table operate under the Default or Global ruleset. This covers most iRacing series that are not directly tied to a real-world sanctioning body’s pit procedures. Under the Default ruleset, stops are more flexible and the timing is less restrictive. If you race primarily in club-level or non-licensed series, this is almost certainly your ruleset. Your pit stop strategy does not need to change from what worked in previous seasons.
What It Means for Strategy
Before entering a series in Season 3, check which ruleset it runs under. Confirm your pit stop timing expectations before your first race. Strategy calls built around the wrong pit window can cost you a race result. A series that shifts from the Global ruleset to IMSA-spec timing changes how aggressively you can stack service under a full course yellow. The minimum box time cannot be bypassed regardless of how little work you request.
The broader takeaway is that pit timing is now part of your pre-race homework. In endurance racing especially, a misread on stop duration can cascade into multiple problems. A wrong lap delta at a caution restart, an incorrect fuel stint calculation, or a penalty for leaving the box early are all avoidable. Spending five minutes with the reference guide before a race in a new series removes that variable. In shorter sprint races the ruleset matters less, but in anything over an hour it becomes a real factor in race management.
The reference table is organized by ruleset rather than by series, so you can quickly identify your class and find the applicable rules. Challiner noted in the post that the table will be maintained and updated if additional rulesets are added during the season. It is worth bookmarking if you run multiple series across the GT3, GTP, or endurance classes in Season 3.
