Stopwatch

It was 45 years ago on February 1-2, 1975 that IMSA began sanctioning the 24 Hours of Daytona, an event that Bill France Sr. had built into international prominence starting in 1962 with a 3-hour Daytona Continental. With excerpts from "IMSA 1969-1989," Mitch Bishop recalls the 1975 event and how it propelled Peter Gregg and Hurley Haywood to stardom.

Much of the development of the now-iconic Porsche 917 was conducted in secret before running its first few races in 1969. What was not a secret was the car had significant handling issues, especially at high speed. Porsche engineers worked on the issue throughout the 1969 season, but it was a hunch and a bit of aerodynamic patchwork that solved the problem. In this post from noted Porsche 917 author Jay Gillotti, he recounts the top-secret test at the end of 1969 at Daytona that would ultimately determine the fate of the 917.

The 24 Hours of Daytona is one of the most prestigious sports car endurance races on the international racing calendar today. But it wasn't always run as a "once around the clock" event. Find out why in this story from contributor Martin Raffauf, who has attended a fair number of these events himself in the last 50 years.

In this excerpt from the recently released book on the development of the Hans device, Jonathan Ingram tells the story of Jim Downing's awakening to the dangers of frontal impact in race cars. It was from this awakening that Jim and co-inventor Dr. Robert Hubbard came up with the idea for the life-saving Hans device that is now used by more than 275,000 drivers globally.

The Porsche 917 holds a special place in the hearts of many race fans. Its flat-twelve cylinder engine sounded like nothing else on the planet and its sleek design set a benchmark for all that followed. This is the story of the very first 917 - chassis number 001.

IMSA was just a year old when it held one of its first sedan races at Alabama International Motor Speedway (now Talladega) in November 1970. To show their support, NASCAR founder and IMSA investor Bill France, Sr. and his son, Bill France, Jr., drove matching Ford Cortinas in the race. Here are some rare photos from the IMSA collection at the IMRRC that document the day.

The fight for the 1992 Winston Cup championship came down the wire at Atlanta Motor Speedway. It was a duel between a number of drivers that had a mathematical chance at winning the coveted NASCAR title. Read about how it all went down in this recap from historian Don Capps.

This fascinating first-hand account by Luis Martinez tells the story of the Grand Prix race held on an airport circuit in Havana, Cuba in 1960 and includes some very rare photos from the event.

Building IMSA into a global powerhouse of sportscar racing in its first 20 years was a team effort. No one made "Racing with a Difference" more real for competitors than Charlie Rainville, IMSA's first chief steward and race director. Charlie was one of a kind and set a standard that is still followed today.

The relationship between IMSA, the FIA and the organizers of the 24 Hours of Le Mans has taken many turns over the years. Read about how it all got started in the early days of IMSA, through the GTP era.