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IMSA Since 1969 · North America

International Motor Sports Association

The Birth of
American Endurance

Founded in 1969 by John Bishop, IMSA became the definitive arena for sports car racing in North America — a series defined by machinery pushed to its absolute limit, day and night.

1969
Founded
24
Hours of Daytona
12
Hours of Sebring
50+
Years of History
1969
IMSA Founded
John Bishop and NASCAR founder Bill France Sr. establish the International Motor Sports Association, creating a unified set of rules for North American sports car racing. The series quickly attracts support from major manufacturers.
1971–1977
Multi-Class Racing & The GTX Era
IMSA's GTO and GTU classes let very different cars race side by side. Multi-class racing becomes the series' greatest strength. In 1977 the GTX class opens the door to turbocharged silhouette racers, and the Porsche 935 becomes the car to beat.
1981–1993
The GTP Era & Peak Factory Warfare
The Grand Touring Prototype class turns IMSA into a battleground for Porsche, Jaguar, Nissan and Toyota, with purpose-built prototypes producing over 700bhp. The Porsche 962 wins the IMSA GTP title every year from 1985 to 1988 and wins the Daytona 24 Hours five times.
1994
World Sports Cars Replace GTP
With costs out of control, IMSA replaces GTP with cheaper open-top World Sports Car (WSC) prototypes. The Ferrari 333 SP and Riley & Scott Mk III become the stars of the new era.
1999–2013
ALMS vs Grand-Am
Don Panoz launches the American Le Mans Series in 1999 using Le Mans rules, carrying the IMSA name into the 21st century. A rival series, Grand-Am, starts in 2000 with the Daytona 24 Hours as its crown jewel. American sports car racing is split in two for 14 years.
2014
IMSA WeatherTech Championship Born
The merger of Grand-Am and the American Le Mans Series creates today's IMSA WeatherTech SportsCar Championship, with Prototype, Prototype Challenge, GTLM and GTD classes. The DPi formula follows in 2017.
2023
GTP Returns & The Hybrid Era
The famous GTP name comes back for a new top class of hybrid LMDh prototypes. Porsche, Cadillac, BMW and Acura all build factory cars, and the same machines can now race at both Daytona and Le Mans.

IMSA Legends

Hurley Haywood
59
Hurley Haywood
United States
Endurance Icon

One of the greatest endurance racers America has produced. Hurley Haywood shares the record for most Daytona 24 Hours victories, with wins spanning almost two decades. He also won Le Mans three times, in three different Porsches, and was one of the first drivers to complete endurance racing's informal Triple Crown of Daytona, Le Mans and Sebring.

5× Daytona 24 Hours winner (1973, 1975, 1977, 1979, 1991)
3× Le Mans winner (1977, 1983, 1994)
2× Sebring 12 Hours winner (1973, 1981)
IMSA GT Champion (1971, 1972)
Scott Pruett
01
Scott Pruett
United States
Daytona Master

Scott Pruett matched Hurley Haywood's record of five Daytona 24 Hours wins, the last four with Chip Ganassi Racing. He won titles in almost everything with a roof: IMSA GTO, Trans-Am and five Grand-Am prototype championships. He also won his class at Le Mans with Corvette. He retired after the 2018 Rolex 24, fifty years after he started racing.

5× Daytona 24 Hours winner (1994, 2007, 2008, 2011, 2013)
5× Grand-Am prototype champion
2× IMSA GTO champion (1986, 1988)
Le Mans GTS class winner, 2001 (Corvette)
Al Holbert's Löwenbräu Porsche 962, No. 14
14
Al Holbert
United States
Porsche Ace

The driver who defined IMSA's GTP golden age. Al Holbert won five IMSA GT championships, three of them in the GTP era, and once held the record for most IMSA race wins with 50. He also won Le Mans three times and the Daytona 24 Hours twice with Porsche, and ran Porsche's North American motorsport division. He died in a plane crash in 1988, aged 41.

5× IMSA GT Champion (incl. GTP 1983, 1985, 1986)
3× Le Mans winner (1983, 1986, 1987)
2× Daytona 24 Hours winner (1986, 1987)
2× Sebring 12 Hours winner (1976, 1981)

Prototype Icons

Porsche 962
Porsche

962

The most successful sports prototype ever built. Designed for IMSA's GTP rules, the 962 won the IMSA title every year from 1985 to 1988 and the Daytona 24 Hours five times. As the 962C it also won Le Mans in 1986 and 1987. Private teams kept racing them for almost a decade.

~700 hp
Power
Turbo
Flat-6
5
Daytona Wins
1984
Debut
Jaguar XJR-9
Jaguar / TWR

XJR-9

The car that broke Porsche's grip. Built by Tom Walkinshaw Racing, the V12 XJR-9 won the Daytona 24 Hours on its debut in 1988. Later that year it won Le Mans, Jaguar's first win there since 1957 and the first time since 1980 that Porsche didn't win.

750 hp
Power
6.0L
V12 (IMSA)
880 kg
Weight
1988
Daytona & Le Mans
Cadillac DPi-V.R
Cadillac

DPi-V.R

The king of the DPi era. Powered by a 5.5-litre V8, the Cadillac won the Daytona 24 Hours four years in a row from 2017 to 2020 and took three IMSA championships. It won 27 of its 59 races, making it the benchmark prototype of modern IMSA.

~600 hp
Power
5.5L
V8
930 kg
Weight
4
Daytona Wins

"If everything seems under control, you're just not going fast enough."

Mario Andretti

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