If you ever wanted to compete in the longest closed-course endurance race in North America, this is your opportunity, and it’s right in the heart of America.
Registration for the NASA 25 Hours at Ozarks International Raceway, the great American race, opens on Independence Day, July 4, 2025.
The race is as challenging as ever, but everything else about it will be easier. Along with the venue change from Thunderhill, the NASA 25 Hours at Ozarks also will benefit from a raft of other exciting changes this year we think racers will love.
All-New Simplified Registration Process
Thanks to feedback from teams and drivers, we have simplified the registration process. For example, a team owner can register the team, and drivers can register themselves. The new entry system is far less complex than it was in years past.
Early Bird registration opens July 4, 2025, at noon Central Time. General registration begins August 1, 2025. Late registration starts October 1, 2025, when increased fees will apply.
Teams that take advantage of Early Bird registration can participate in the preregistration parking option when that process opens August 4. Preregistration parking gives teams early access to secure their grid spot, garage space, and paddock assignment. There are 50 garage spaces. Entries are capped at 62 teams.
New Classing Structure
Classes for the NASA 25 Hours at Ozarks have been retooled, which should make it easier to understand what the classes actually mean. Also, in the interest of decreasing speed differentials among classes while enhancing parity, we have reduced the number of classes from eight to five.
Prototypes and Sports Racers
HYC — (Hypercar)
Fastest class, no limits on modifications. NASA Super Unlimited rules apply.
PLE — (Prototype Lite Endurance)
Same rules as HYC. Vehicles are restricted to having less than 2.5 liters displacement naturally aspirated, or 1.3 liters with forced induction.
Grand Touring Cars, Production Cars and Tin Tops
GTE — (Grand Touring Endurance)
Uses NASA Super Touring GT rules. Unlimited modifications for GT style cars.
STE — (Super Touring Endurance)
Uses NASA Super Touring 2 rules.
TCE — (Touring Car Endurance)
Uses NASA Super Touring 4 rules.
To qualify to start the race, any entered team will need to complete a lap during warm up or qualifying Friday during the event that is at least 2 minutes, 45 seconds or faster. This means that, in general, cars need to roughly meet NASA Super Touring 4 characteristics to gain entry into this event.
Pitting During Safety Car and Full Course Yellow
For the first time in the event’s history, we will permit teams to enter the pits during full-course yellow or safety car periods. This is in direct response to customer feedback, which should increase opportunities for teams to use pit stops as part of their strategies.
New Safety Car Protocols
New for 2025, during safety car periods, the field will be reorganized to enhance the competition during the event, allow lap traffic to be reshuffled out of the middle of the field, and make the racing more enjoyable for the competitors on track.
Event Schedule
The event will kick off with an opening ceremony on Friday evening. Thursday track day/night practice sanctioned by NASA MidAmerica.
Time Activity
Friday, 3:00 – 4:45 p.m. Warmup
Friday, 5:00 – 6:00 p.m. Qualifying
Saturday, 11:00 a.m. Race Begins
Sunday, Noon Race Ends
Event registration opens July 4, 2025 at noon.
About Ozarks International Raceway
Centrally located in the United States, Ozarks International Raceway is a 3.97-mile-long track and a state-of-the-art facility in the heart of the Ozarks. The track has 19 thrilling corners, 150 feet of elevation change overall, and 1,200 feet elevation change over a single lap.
Click here to read some driving tips on Ozarks International Raceway.
Volunteer Opportunities
Want to be part of the action without racing? We have numerous volunteer opportunities available! Please visit our website to sign up.
