Fact-checked by Grok 2 weeks ago

IMSA

The International Motor Sports Association (IMSA) is a premier sanctioning body for professional sports car racing in North America, organizing high-profile endurance events that emphasize speed, strategy, and technological innovation in multi-class competitions. Founded in 1969 by John and Peggy Bishop, former executives with the Sports Car Club of America, with assistance from Bill France Sr., the founder of NASCAR, IMSA emerged as an alternative to established racing organizations like the United States Auto Club, aiming to promote diverse motorsport series including open-wheel and sports car formats. Its inaugural event took place in October 1969 at Pocono Raceway in Pennsylvania, featuring Formula Vee and Formula Ford races attended by just 348 spectators, marking a modest start amid financial challenges such as high track rental fees. By 1971, IMSA pivoted toward sports car racing, debuting its GT series at Virginia International Raceway with 24 entries, and soon secured major sponsorship from R.J. Reynolds Tobacco Company for the Camel GT Championship, which propelled growth through the 1970s and 1980s with iconic races at tracks like Daytona International Speedway and Sebring. Over the decades, IMSA underwent significant transformations, including ownership changes in the —first sold in 1994 and again in 1996—before automotive entrepreneur acquired it in 1999 and launched the (ALMS) to elevate international competition. In 2012, acquired IMSA and merged it with its Grand-Am Road Racing subsidiary, creating the unified Tudor United SportsCar Championship, which was rebranded as the current IMSA WeatherTech SportsCar Championship in 2016, featuring classes such as GTP (Grand Touring Prototype), LMP2, GTD Pro, and GTD for a mix of manufacturer-backed prototypes and GT cars. Today, IMSA sanctions a robust calendar of events, headlined by endurance classics like the Rolex 24 at Daytona (a 24-hour race held annually since 1962, integrated into IMSA programming), the 12 Hours of Sebring, and the Motul Petit Le Mans at Road Atlanta, drawing global manufacturers including Porsche, Ferrari, Acura, and Cadillac while fostering advancements in hybrid and sustainable racing technologies. With headquarters in Daytona Beach, Florida, and affiliation under the ACCUS/FIA umbrella, IMSA remains the leading force in North American sports car racing, boasting increasing attendance, broadcast partnerships, and a legacy of nurturing talents who have excelled in Formula 1, IndyCar, and NASCAR.

History

Origins and Formation

John Bishop, the former executive director of the Sports Car Club of America (SCCA), played a pivotal role in the origins of the International Motor Sports Association (IMSA). Having contributed to the development of SCCA's professional series like Trans-Am and Can-Am, Bishop grew frustrated with the organization's internal politics and its emphasis on amateur racing over professional development. In 1969, amid escalating tensions and in-fighting within the SCCA, Bishop resigned and, along with his wife Peggy Bishop and NASCAR founder Bill France Sr., established IMSA as a new sanctioning body dedicated to elevating sports car racing through a more professional framework. IMSA began with open-wheel formula car events, including its debut and races in 1969, and some oval racing in 1970, before pivoting toward Grand Touring (GT) cars in 1971 to position the series as a direct professional counterpart to the SCCA's club-oriented events. The organization launched the that year, featuring a schedule of endurance-style races that attracted both factory-supported teams and privateers with modified production vehicles. This championship emphasized competitive balance and spectacle, drawing competitors seeking a platform beyond the SCCA's amateur constraints. Early seasons included diverse classes, but GT machinery soon dominated, setting the tone for IMSA's focus on accessible yet high-performance . From its inception, IMSA prioritized safety innovations that distinguished it from contemporaries, mandating features like approved fuel cells and robust structures to mitigate fire risks and structural failures in high-speed crashes. These regulations, outlined in IMSA's early competition rules, required fuel cells in GT classes by the mid-1970s and stipulated multi-point s attached to the for protection—standards that were ahead of many sanctioning bodies at the time. Such measures reflected Bishop's vision for safer professional racing environments. IMSA's debut events underscored its grassroots-to-professional transition, beginning with a Formula Ford race at Pocono International Raceway on October 19, 1969, won by Jim Clarke. Subsequent years built momentum, with the 1972 Camel 500 km at Watkins Glen serving as a key precursor to fuller championships, where Peter Gregg and claimed victory in a , highlighting the series' growing appeal among GT racers.

GT Championship Era

The , later known as the Camel GT Championship following sponsorship from starting in 1972, marked a period of significant growth for IMSA through the and . This era featured endurance races at iconic venues like and , attracting top GT machinery from manufacturers such as , , and . The series emphasized multi-class racing with GTP (Grand Touring ) classes introduced in the , blending production-based GT cars with more advanced prototypes, which boosted competitiveness and spectator interest. Camel GT events, including the and , became staples, drawing large crowds and showcasing technological advancements in design. The championship faced challenges in the late with increasing costs and regulatory changes, leading to ownership transitions in the early .

American Le Mans Integration

In 1999, entrepreneur founded the (ALMS) to revive high-profile endurance in , acquiring and relaunching the International Motor Sports Association (IMSA) as its sanctioning body following the success of the inaugural event the previous year. This move integrated IMSA's legacy in GT racing with a new focus on -inspired formats, drawing from European endurance traditions while incorporating American circuits. The series quickly established itself by emphasizing multi-class competition, including production-based GT cars that echoed IMSA's earlier GT heritage. The introduced prototype classes aligned with regulations, featuring LMP1 for high-powered, manufacturer-backed entries and LMP2 for more accessible, spec-based prototypes starting in 2001, raced alongside GT1 and GT2 categories. These prototypes prioritized speed and technological innovation, with events like the serving as grueling tests of endurance on the bumpy former airfield circuit, often attracting international fields and highlighting reliability under harsh conditions. The multi-class structure allowed prototypes to lead overall while GT cars competed within their divisions, fostering close and strategic pit decisions across varying performance levels. Prototype competition in the ALMS era saw intense manufacturer rivalries, particularly between and , which dominated the LMP classes through the mid-2000s. Audi's diesel-powered R10 TDI secured multiple LMP1 titles from 2006 to 2008, but Porsche's nimble RS Spyder in LMP2 mounted a strong challenge, winning overall at Sebring in 2008 and pressuring Audi with superior agility in shorter sprints. These battles elevated the series' profile, drawing global attention to American events as proxies for Le Mans-style showdowns. From 2010 to 2011, the participated in the Intercontinental Le Mans Cup (ILMC), an international series organized by the that blended ALMS races like with European endurance events such as the 1000 km of and . This concept promoted cross-continental collaboration, awarding points toward a global championship and integrating ALMS prototypes with FIA-governed fields to enhance prestige without fully merging schedules. The period faced significant challenges from the post-2008 global economic downturn, which led to manufacturer withdrawals and reduced factory support. , the defending LMP1 champion, announced its exit from the at the end of 2008, citing financial pressures and a shift toward global programs, leaving a void in prototype entries. Similarly, Peugeot scaled back its diesel prototype efforts, exacerbating grid sparsity and forcing the series to rely more on teams amid sponsorship shortages. These setbacks tested the ' resilience, prompting rule adjustments to balance classes and sustain competitiveness until the 2012 merger announcement with GRAND-AM.

NASCAR Ownership and Reunification

In 2012, NASCAR, under the leadership of Jim France (son of co-founder Bill France Sr.), acquired the ALMS from Don Panoz and merged it with its subsidiary Grand-Am Road Racing to reunify North American sports car racing. This landmark merger created the United SportsCar Racing organization, which launched the Tudor United SportsCar Championship in 2014, combining the best elements of both series including multi-class formats, major endurance events, and manufacturer involvement. The unified series addressed previous fragmentation, standardizing rules for prototypes and GT cars while preserving iconic races like the Rolex 24 at Daytona and Petit Le Mans. In 2017, the championship rebranded as the IMSA WeatherTech SportsCar Championship, reflecting continued growth, increased international participation, and advancements in hybrid technology under NASCAR's stewardship. As of 2025, this era has solidified IMSA's position as the premier sanctioning body for sports car racing in North America.

Organization and Governance

Leadership and Structure

The International Motor Sports Association (IMSA) serves as the primary sanctioning body for professional sports car racing in , overseeing series such as the WeatherTech SportsCar and ensuring compliance with safety, technical, and competitive standards across its events. IMSA operates as a wholly owned of since its acquisition in 2012, maintaining operational independence while benefiting from shared resources and strategic oversight from NASCAR leadership, including direct involvement from figures like . As part of its international alignment, IMSA incorporates FIA-homologated components and standards in its technical regulations to facilitate global compatibility for vehicles and equipment. John Doonan has led IMSA as president since January 1, 2020, succeeding Scott Atherton and bringing expertise from his prior role as North America's Director of Motorsports. Under his tenure, Doonan has emphasized growth in manufacturer participation and fan engagement, with IMSA's integrated into NASCAR's but without a publicly detailed independent board composition beyond executive leadership. IMSA's organizational framework includes key departments such as competition operations, technical services, and marketing, coordinated through a headquarters in , to manage event sanctioning, rule enforcement, and series promotion. These divisions handle aspects like medical liaison, officiating, and , supporting a staff that oversees multiple professional and support series annually. In the 2025 State of the Sport address, IMSA outlined initiatives for grid expansions, including potential additions of full-season entries for the 2026 WeatherTech SportsCar Championship while noting constraints like pit lane limitations at events such as the Rolex 24 at Daytona. Sustainability efforts were highlighted through a new Michelin-sponsored award for the GTP class, recognizing the highest sustainability performance based on tire usage, energy efficiency, and race results starting in 2026, aligning with broader goals for reduced environmental impact in motorsports.

Rules and Technical Regulations

IMSA's governance is supported by comprehensive rules and regulations that ensure fair, safe, and competitive racing. The Sporting Regulations outline the conduct of events, including licensing requirements, race procedures, penalties, and series-specific supplementary rules for competitions like the WeatherTech SportsCar Championship. Technical Regulations provide detailed specifications for vehicles in each class, covering , engines, , safety equipment, and performance balancing to promote parity and innovation while incorporating FIA standards for and global compatibility. These regulations are updated annually; for 2025, they include provisions for hybrid powertrains in the GTP class and sustainable fuel usage across prototypes.

Racing Classes

Prototype Classes

The prototype classes in the IMSA WeatherTech SportsCar Championship consist of Grand Touring Prototype (GTP) and Le Mans Prototype 2 (LMP2) vehicles, which represent the highest levels of technological development in sports car racing. Grand Touring Prototype (GTP): Introduced in 2023, GTP cars feature a standardized hybrid powertrain that captures kinetic energy from braking and stores it in batteries for deployment. As of 2025, six manufacturers compete: Acura, Aston Martin, BMW, Cadillac, Lamborghini, and Porsche, each with distinct internal combustion engines and aerodynamic bodywork. Le Mans Prototype 2 (LMP2): These are closed-cockpit prototypes built by four approved constructors (, , , and ). LMP2 cars are designed for parity across the field and also compete in international series such as the , including the .

Grand Touring Classes

The grand touring classes include GT Daytona Pro (GTD Pro) and GT Daytona (GTD), both utilizing GT3-homologated production-based sports cars adapted for racing. These classes emphasize manufacturer involvement and driver talent in a spec-regulated environment. GT Daytona Pro (GTD Pro): Debuting in 2022 and following FIA GT3 regulations, GTD Pro features factory-supported teams with professional drivers. Competing manufacturers as of 2025 include , , Chevrolet, Ferrari, Ford, , , , and . GT Daytona (GTD): Similar to GTD Pro, GTD cars adhere to FIA GT3 specifications but are primarily run by customer teams with a mix of professional and gentleman drivers. Manufacturers include , , Chevrolet, Ferrari, , , , and .

Current Series

WeatherTech SportsCar Championship

The WeatherTech SportsCar Championship serves as the premier series of the International Motor Sports Association (IMSA), featuring multi-class and sprint across North America's premier courses. Established as the flagship competition, it integrates high-performance prototypes and grand touring cars in a format that emphasizes both team strategy and manufacturer rivalry, with events ranging from sprints under two hours to races exceeding 24 hours. The 2025 season comprises 11 events, beginning with the Rolex 24 At Daytona in January, followed by the Mobil 1 Twelve Hours of Sebring in March, and concluding with the MOTUL Petit Le Mans in October at Michelin Raceway Road Atlanta. Key races include the 100-minute sprints at Long Beach and , the 2-hour-40-minute events at , Mosport, , and , and the six-hour endurance challenges at Watkins Glen (The Glen) and . This balances regional accessibility with iconic endurance tests, awarding points toward overall and class-specific titles. Competition unfolds across integrated classes—Grand Touring Prototype (GTP), GT Daytona Pro (GTD Pro), and GT Daytona (GTD)—where vehicles start together but are scored separately, fostering intense on-track battles while maintaining class parity through regulations. Le Mans Daytona hybrid (LMDh) and (LMH) machinery dominate GTP, while GTD Pro fields factory-supported GT3 entries and GTD includes customer and pro-am GT3 cars. Championships are awarded for drivers, teams, and manufacturers in each class, with points scaled by race distance and finishing position to reward consistency across the season. Broadcast coverage is handled exclusively by , delivering over 160 hours of live programming across , , and Peacock streaming, including international distribution to 124 territories. The 2025 season marked a significant uptick in linear TV viewership, averaging 393,000 viewers on and —up 70% from 2024—and achieving the highest figures since at least 2014, driven by enhanced digital engagement on Peacock and . Iconic moments define the series' legacy, such as the Tequila Patrón ESM team's overall victories at the 2016 Rolex 24 At and Mobil 1 Twelve Hours of Sebring, showcasing the ARX-05's early prototype prowess. The 2025 season featured refreshed grids at , with a 61-car field reflecting lineup changes across all classes, including new driver pairings in GTP and expanded manufacturer representation in GTD Pro.

Michelin Pilot Challenge

The is a grand touring and endurance racing series sanctioned by the International Motor Sports Association (IMSA), featuring competitions for Grand Sport (GS) and (TCR) classes. It serves as an entry-level platform within the IMSA ecosystem, emphasizing close racing with production-based vehicles and a blend of professional and amateur drivers. Races typically last two hours, with exceptions for longer events like the season-opening four-hour BMW M Endurance Challenge at , and often support the WeatherTech SportsCar Championship weekend schedule. The series comprises two primary classes: GS, which utilizes SRO-homologated GT4 specification cars from manufacturers such as , , , , , , and , producing approximately 400-450 horsepower and capable of speeds exceeding 160 mph; and TCR, which features (WTCR)-homologated touring cars from brands including , , , and , with engines around 300-350 horsepower and top speeds over 140 mph. Performance is balanced across entries through (BoP) adjustments, including variations in fuel capacity, ride height, power output, and minimum weight, ensuring competitive parity. Representative examples include the Cayman GT4 RS Clubsport in GS and the in the TCR class. The 2025 season calendar consists of 10 rounds, primarily held at prominent North American circuits and integrated with major IMSA events. Key dates include January 25 at (four hours), March 15 at (two hours), May 11 at WeatherTech Raceway Laguna Seca (two hours), June 7 at (four hours, standalone), June 28 at (two hours), July 12 at (two hours), August 2 at (two hours), August 23 at (two hours), September 20 at (two hours), and October 10 at Michelin Raceway Road Atlanta (two hours). Each event awards points toward separate driver and team championships in GS and TCR, calculated based on finishing positions with a maximum of 320 points for a class win, fostering season-long competition. Teams in the Michelin Pilot Challenge commonly pair experienced professionals with amateur drivers, promoting skill development and accessibility for emerging talent, as evidenced by 2025 champions like 45-year-old veteran Jan Heylen alongside 19-year-old rookies in mixed lineups. This structure positions the series as a developmental pathway, with standout performers often advancing to higher IMSA divisions such as the GTD class in the WeatherTech SportsCar . Michelin has been the title sponsor and exclusive tire supplier since 2019, succeeding , and leverages the series for ongoing , gathering data from over one million competitive miles to refine high-performance road and racing tires.

VP Racing SportsCar Challenge

The VP Racing SportsCar Challenge is a multi-class sprint series sanctioned by IMSA, introduced in as an accessible entry point for prototypes and grand touring cars, targeting amateur and semi-professional drivers. It features short, intense races on select WeatherTech SportsCar Championship weekends, emphasizing driver development and cost-effective competition with spec parts and limited modifications. The series includes three classes: 3 (P3) for LMP3-spec prototypes from constructors like , Ginetta, and Norma, producing around 420-450 horsepower from 5-liter V8 engines; Grand Sport X (GSX) for GT4-based cars similar to Michelin Pilot Challenge GS, including Cayman, , and ; and the new Grand Touring Daytona X (GTDX) class added for 2025, featuring GT3-spec machinery like 911 GT3 R and Ferrari 296 GTB, aimed at bridging to higher-level . ensures parity, with races consisting of two 45-minute sprints per weekend following 15-minute practice sessions. The 2025 season featured six double-header events: January 20 at , March 15 at , May 11 at WeatherTech Raceway Laguna Seca, June 28 at , August 23 at , and October 10 at Michelin Raceway Road Atlanta. Points are awarded separately for each class toward drivers', teams', and manufacturers' championships, with a focus on consistency in the sprint format. VP Racing Fuels has been the title sponsor since the series' , supporting fuel technology advancements through on-track data. The series saw expanded entries in 2025, including the GTDX debut with over 20 cars in some fields, and introduced a driver to highlight amateur achievements.

Support Series

Porsche Carrera Cup North America

The Porsche Carrera Cup is a one-make series sanctioned by Porsche Motorsport and co-sanctioned by IMSA, featuring professional and amateur drivers competing in identical Cup cars. The series uses the Cup (type 992) for the 2025 season, powered by a 4.0-liter naturally aspirated producing 510 horsepower, paired with a six-speed sequential gearbox and racing tires. It serves as a development platform for drivers aiming to progress to higher levels of , including IMSA's WeatherTech SportsCar Championship GTD classes. The championship is divided into three classes based on driver experience and age: for professional drivers, Pro-Am for semi-professionals and gentlemen drivers, and Masters for competitors aged 50 and over. All classes use the same car specification to emphasize driver skill, with races held in a double-header format typically consisting of two 45-minute sprints per weekend. The series races on prominent North American circuits, often as support to IMSA events and select Formula 1 grands prix. For the 2025 season, consisted of eight double-header weekends, totaling 16 races, beginning on March 12 at and concluding on October 19 at . Key venues included the Grand Prix of Long Beach, , and IMSA endurance races at Watkins Glen and , providing exposure alongside major championships. The season featured the transition to the new 911 GT3 Cup (type 992.2) announced for 2026, but 2025 utilized the prior model.

Ferrari Challenge North America

The North America is a single-marque series organized by Ferrari's Corse Clienti department and co-sanctioned by the International Motor Sports Association (IMSA), featuring Challenge race cars derived from GT3 specifications. These mid-engine cars are powered by a 3.0-liter twin-turbocharged producing approximately 700 horsepower, paired with a six-speed sequential gearbox and slick tires optimized for the series. The series emphasizes amateur and semi-professional drivers, providing a platform for Ferrari customers to compete in a controlled environment that parallels the Grand Touring classes in IMSA-sanctioned events. The competition is divided into two primary classes based on driver experience: the Trofeo for more seasoned competitors, including professionals and advanced amateurs, and the Coppa for gentlemen drivers with less background. Each class further subdivides into amateur categories (Trofeo Pirelli Am and Coppa Shell Am) to ensure fair matchups, with all entrants using identical 296 Challenge cars to highlight driver skill over mechanical differences. Races are typically 30-minute sprints held in double-header format, focusing on close-wheel-to-wheel action without the complexity of elements found in broader GT categories. For the 2025 season, the series comprised six event weekends across , delivering 12 races in total, with support billing at prominent IMSA venues such as WeatherTech Raceway . The calendar included opening rounds at (March 5-9), (April 9-13), Miami's Homestead-Miami Speedway (May 14-18), (June 25-29), (July 23-27), and a season finale at (September 10-14). This structure allowed participants to race alongside major IMSA championships, culminating in the Finali Mondiali at in for n champions. The series underscores customer racing by enabling Ferrari owners to purchase and campaign factory-prepared 296 Challenge cars through authorized dealers, with comprehensive support from Ferrari Corse Clienti including technical assistance, logistics, and driver coaching programs. This model has fostered a community of over 1,000 participants since the series' in 1993, promoting and accessible . Historically, integration with IMSA began in 2010 for select rounds, evolving into full co-sanctioning by 2015 with multi-year agreements that align the with IMSA's premier events.

Lamborghini Super Trofeo North America

The North America is a one-make series organized by Squadra Corse and co-sanctioned by IMSA, utilizing the Super Trofeo EVO2 race cars in support of the WeatherTech SportsCar Championship. The mid-engine cars feature a 5.2-liter naturally aspirated delivering 620 horsepower, coupled with a six-speed sequential gearbox and slick tires designed for sprint . The series targets professional, semi-professional, and amateur drivers, offering a competitive outlet for Lamborghini customers while mirroring the intensity of in IMSA events. Competitors are categorized into four classes: for factory and top professionals, for teams with one pro and one amateur, Am for all-amateur lineups, and LB Cup for female drivers. Identical cars across classes ensure parity, with emphasis on driver ability in wheel-to-wheel combat. Races follow a double-header format of two 50-minute endurance-style sprints per weekend, incorporating strategy elements like pit stops for fuel and tires. The 2025 season, the 13th for the series, featured six rounds primarily in , concluding with the World Final abroad, and ran from March to September before the international finale. The schedule included (March 12-14), WeatherTech Raceway Laguna Seca (May 9-11), (June 19-21), (August 1-3), (September 18-20), and the season-closing World Final at Misano World Circuit in (November 6-7). These events aligned with IMSA's , enhancing visibility and providing a pathway for drivers to GT categories. Lamborghini supports entrants through factory-prepared cars available via authorized teams, offering logistics, technical aid, and coaching to build a global community since the North American debut in 2013. Full IMSA co-sanctioning has been in place since , solidifying its role in the support series ecosystem.

Circuits and Events

Major Circuits

Daytona International Speedway serves as a cornerstone venue for IMSA events, featuring a 3.56-mile road course that combines elements of an oval and infield layout, including high-banked turns and technical sections. This hybrid configuration has hosted the Rolex 24 At endurance race annually since its inception in 1962, marking the season opener for the WeatherTech SportsCar Championship and testing teams with its mix of high-speed straights and elevation changes. The track's layout, originally designed in the 1950s, accommodates multiple classes and draws large crowds for its endurance-focused challenges. Sebring International Raceway is renowned for its demanding 3.74-mile circuit built on a former airfield, characterized by bumpy concrete surfaces and 17 turns that emphasize and car setup durability. It has been the site of the Mobil 1 Twelve Hours of Sebring since the event's debut on March 15, 1952, establishing it as one of the oldest races in and a key fixture in IMSA's Endurance Cup. The track's irregular pavement and variable weather conditions create unique challenges, often leading to mechanical attrition that highlights the resilience required in IMSA competitions. WeatherTech Raceway Laguna Seca offers a 2.238-mile road course in , famous for its 11 turns, including the iconic —a blind, steeply descending left-right that drops 59 feet over 450 feet, demanding precise driver commitment. This venue hosts sprint races like the TireRack.com Monterey SportsCar Championship in the WeatherTech series, utilizing its 180-foot total elevation change to favor agile prototypes and GT cars. Opened in 1957, Laguna Seca has been a staple IMSA circuit since the 1970s, providing a contrasting technical layout to the series' endurance tracks. In 2025, the (COTA) returns to the IMSA schedule as a rotational addition for support series, featuring its 3.41-mile, 20-turn layout inspired by classic European circuits, complete with a backstraight esses section and a steep uphill climb to Turn 1. Located in , COTA hosts early-season events like the VP Racing SportsCar Challenge, as well as later events for series such as North America, offering a modern facility that accommodates various IMSA support categories while integrating with the broader motorsport calendar. Its inclusion enhances geographic diversity in IMSA's venue lineup, drawing on its history of hosting international series since opening in 2012.

Key Events and Formats

The IMSA WeatherTech SportsCar Championship features a mix of sprint and race formats across its calendar. Sprint races, typically lasting 2 hours and 40 minutes, emphasize qualifying pace and over fewer pit stops, while events extend to 6 hours, 12 hours, or the 24-hour 24 at , incorporating mandatory driver stints, nighttime racing, and increased mechanical challenges. The series also includes the Endurance Cup (MEC), comprising five longer races that award separate points: the 24, , 6 Hours of Watkins Glen, Motul Course de Monterey at (4 hours in select years), and (10 hours). Support series events often run concurrently, with formats varying by category, such as 45-minute races in the Pilot Challenge or sprint formats in the VP Racing SportsCar Challenge.

Defunct Series

Early IMSA Championships

The International Motor Sports Association (IMSA) launched its flagship in 1971, initially featuring two primary classes: GTO for grand touring cars with engines over 2.5 liters and GTU for those under 2.5 liters, aligning GTU with FIA Group 2 regulations for modified production vehicles. The inaugural event, the Danville 300 at , marked the series' debut, emphasizing American-style endurance racing with a mix of and drivers. By the late , the introduction of the GTX class for turbocharged prototypes like the 935 elevated competition, leading to dominance by Porsche entries. The 1981 season brought the GTP (Grand Touring Prototype) class, featuring purpose-built racers such as the T600 and , with notable champions including Brian Redman in 1981 and Al Holbert in 1983. GTU served as a feeder category, fostering talents in production-based cars like models, while economic pressures and escalating costs in the GTP era—coupled with safety concerns over high speeds—contributed to the championship's restructuring into the World Sports Car series by 1994. In parallel, the IMSA Firestone Firehawk Series emerged in the mid-1980s as a spec platform for near-stock production cars, utilizing Firestone's high-performance tires to ensure parity and affordability. Sponsored by Firestone, it ran endurance-style events from 1985 through the early 1990s, attracting entries like 944s and Camaros in a format that emphasized reliability over outright speed, with races often lasting several hours at circuits like . The series built on the growing popularity of street-stock endurance in the 1970s, providing a alternative to the high-tech GTP battles, though it gradually phased out amid IMSA's shift toward more professionalized categories by the mid-1990s. The IMSA Supercar Championship, active from 1991 to 1993 under sponsorship, targeted high-performance road-going s in sprint races across U.S. venues like Watkins Glen and , featuring 7 to 9 events per season. It showcased exotic entries including Turbos and X180Rs, featuring exotic production-based entries including Turbos, X180Rs, and 300ZXs that highlighted international engineering on American circuits. Champions like in a in 1993 underscored the series' brief but intense focus on unmodified supercar speed, but it ended after 1993 due to overlapping with evolving GT formats and waning manufacturer interest. Earlier entry-level efforts included the Cup in the mid-, a disposable, low-cost stock series for Renault Le Cars designed to draw large fields through minimal modifications and high-volume participation. Launched around 1975, it ran regional events like East and West Coast championships through the early , emphasizing affordability for amateur racers before fading as Renault's U.S. market presence declined. Complementing this, IMSA's Showroom Stock category in the and expanded on production-car racing, evolving from international sedan roots to include near-stock vehicles in support races, peaking in the with strong fields at IMSA weekends. These classes provided accessible competition, with events like those at fostering grassroots involvement until broader series reforms in the 1990s absorbed or discontinued them.

Acquired and Merged Series

In 1999, businessman acquired the International Motor Sports Association (IMSA) and subsequently launched the (), an endurance-focused championship emphasizing prototype and GT categories that drew from European traditions while adapting to North American circuits. The operated independently under IMSA sanctioning until 2013, featuring high-profile events like the and , and promoting manufacturer involvement from teams such as , , and itself. In 2014, IMSA merged the with the rival series to create the United SportsCar Championship, which was rebranded as the WeatherTech SportsCar Championship in 2017, effectively ending the standalone structure while integrating its endurance format into IMSA's flagship program. The Star Mazda Series, an open-wheel feeder championship using identical Mazda-powered chassis, was integrated into IMSA's ecosystem during the 2000s as a support series to the , providing affordable entry-level racing for aspiring drivers on road courses across . Originally established in 1991, it gained prominence under IMSA sanctioning starting in 1999, aligning with the schedule and serving as a developmental pathway similar to USA in structure and purpose, though operating independently until its rebranding. The series concluded its run under IMSA in 2011, transitioning to the Mazda Road to Indy ladder under sanctioning and evolving into the Pro Mazda Championship, marking the end of its direct affiliation with IMSA's sports car programs. Launched in the mid-2000s as the IMSA Prototype Lites, the IMSA Prototype Challenge introduced spec-series racing for lightweight prototypes, acting as an early precursor to the LMP3 category with standardized engines and to control costs and encourage participation. Renamed Prototype Challenge in 2010, it featured Pro-Am and professional classes on and Grand-Am support bills, but was discontinued after the 2022 season as part of IMSA's restructuring, with its LMP3 elements transitioning into the VP Racing SportsCar Challenge. IMSA assumed sanctioning responsibilities for the Atlantic Championship in 2008, acquiring oversight from the Sports Car Club of America (SCCA) Pro Racing for the 2009-2011 seasons, during which the open-wheel series utilized chassis and engines on a mix of road and street circuits. The championship, known for nurturing talents like and , faced declining entries and financial challenges, leading to its discontinuation after 2011; its developmental role was subsequently absorbed into higher open-wheel ladders, including Indy Lights. During the , IMSA incorporated the Panoz Racing Series, a regional one-make competition for modified GTLM vehicles that supported events and emphasized grassroots with limited modifications for parity. Similarly, the Ultra 94 Porsche Cup, established in 2011 as a Canadian-focused one-make series using Porsche 997 GT3 Cup cars, operated under IMSA sanctioning with events tied to major IMSA weekends. Both series were phased out following the 2014 -Grand-Am merger, as IMSA streamlined its portfolio toward broader GT classes like GTD in the WeatherTech Championship.

International Involvement

Participation in Global Events

IMSA's involvement in global endurance racing, particularly the , traces back to at least 1981, when the series' prototype cars first competed at the event under the emerging GTP regulations, marking the beginning of a sustained presence by North American teams and drivers. Over the decades, IMSA-sanctioned entries have participated consistently, often bridging North American and European racing ecosystems through shared manufacturer programs and driver lineups. A notable milestone came in 2015, when IMSA-affiliated drivers achieved significant success: Nick Tandy and , regular IMSA competitors, secured the overall victory in the No. 19 alongside , while Jordan Taylor, Oliver Gavin, and Tommy Milner won the GTE Pro class in the No. 64 Corvette C7.R for . The convergence of IMSA's Grand Touring Prototype (GTP) class with international standards has been facilitated by the regulations, which ensure eligibility for events like by standardizing powertrains and designs across series. This alignment allows IMSA GTP cars to compete directly in the category with minimal modifications, promoting cross-continental competition. In 2025, this was exemplified by a robust IMSA presence at , including Porsche Penske Motorsport's three entries—earning an automatic invitation via their 2024 IMSA GTP championship—and Cadillac's two-car effort with Whelen Engineering Racing and , both fielding . This multi-manufacturer assault highlighted the seamless integration of technology between IMSA and , with 18 of IMSA's 22 full-season GTP drivers competing at the event. At the 2025 event, while the overall victory went to Ferrari's No. 83 entry, IMSA-affiliated teams like Porsche Penske Motorsport secured strong positions, with the No. 6 finishing second overall. Despite these synergies, IMSA teams face distinct challenges in global events such as , including homologation variances that require fine-tuning to meet (ACO) specifications beyond IMSA's framework, as well as logistical hurdles like transatlantic travel and affecting driver acclimation. These factors demand extensive preparation, from adapting to differing flow limits to managing six-hour shifts, yet they underscore the growing interoperability between IMSA and international circuits.

Partnerships and Expansions

IMSA has pursued strategic manufacturer partnerships to bolster competition in its premier Grand Touring Prototype (GTP) class. In 2025, entered the series through The Heart of Racing team, fielding the GTP car for a full-season campaign, marking the brand's debut in IMSA's top tier. Looking ahead, announced plans to join the GTP class in 2027 with a factory-supported program, expanding Motor Group's presence in endurance racing. also confirmed its intention to launch a factory effort in IMSA by 2027, aiming to leverage the series for development ahead of global competitions. International expansions have included alignments with regional series to grow IMSA's footprint in . North America, sanctioned by IMSA, extended its reach into in 2025 by hosting races at during the Formula 1 du Canada in Montréal, attracting 24 entries and fostering cross-border talent development. These initiatives align with broader efforts to integrate Porsche's one-make racing ecosystem across the continent, though specific ties to Mexican series remain in exploratory phases without confirmed 2025 events. Sponsorship deals have provided financial stability and visibility for IMSA's growth. WeatherTech has served as the title sponsor of the WeatherTech SportsCar Championship since 2017, with the partnership extended through 2030 to support series operations and marketing. Rolex maintains its longstanding role as title sponsor of the Rolex 24 At Daytona, recently expanded into a broader Official Timepiece partnership with IMSA starting in 2025. Additionally, Michelin extended its agreement as the Official Tire of IMSA through 2035, ensuring continued technical support for all classes. These partnerships have driven measurable growth, exemplified by the 2025 Rolex 24 At Daytona entry list reaching a capacity 61 cars across four classes, an increase from 59 cars in 2024. Under NASCAR's ownership since 2012, IMSA has leveraged shared resources to accelerate these expansions.

References

  1. [1]
    IMSA Official Home | Race results, schedule, standings, news, drivers
    Race Weekend Schedule · IMSA TV · IMSA Timing and Scoring · IMSA Radio · FOLLOW US · OFFICIAL PARTNERS.2025 ScheduleIMSA TVStandingsScoring | IMSAWeatherTech
  2. [2]
    50 Years of IMSA: Six Significant Eras of Sports-Car Racing
    Dec 31, 2018 · When John Bishop and his wife Peggy formed IMSA in 1969 with substantial assistance from NASCAR president Bill France, no one knew precisely ...
  3. [3]
    Introduction to IMSA and History of the Organization - Pit Pass Network
    Aug 24, 2023 · IMSA, or International Motorsports Association, was founded by Bill France, Sr. and John Bishop in 1969. The first race was at Pocono Raceway.
  4. [4]
    Timeline – IMSA Hall of Fame
    ” Bishop and France founded the International Motor Sports Association (IMSA) in 1969. ... John Bishop began a 20-year stint as IMSA President, while Peggy Bishop ...
  5. [5]
    John Bishop - Motorsports Hall of Fame
    In the end Bishop left the SCCA and in 1969 founded the International Motor Sports Association (IMSA) in partnership with NASCAR boss Bill France. France ...Missing: departure | Show results with:departure
  6. [6]
    SportsCar Feature: Game Changer - Sports Car Club of America
    May 9, 2016 · Bishop's departure was perhaps the most profound event in the history ... While Bishop always insisted that IMSA was not designed to compete with ...
  7. [7]
    Blast from the Past | IMSA
    Oct 5, 2020 · The first IMSA-sanctioned event came in 1971 as part of the IMSA GT Series, a three-hour race with Dave Heinz and Or Costanzo winning in a ...
  8. [8]
    Early Days at IMSA: Formula Cars on Ovals
    Bishop was committed to not competing with the SCCA, whose professional racing championships were dominating the racing scene; the Trans-Am and Can-Am series ...Missing: departure | Show results with:departure
  9. [9]
    #Focus – The IMSA GT Championship Story. – Historic Motor Sport ...
    Mar 14, 2016 · Back to the championship history, the first champions of the IMSA GT were no other than Peter H. Gregg and Hurley Haywood back in 1971 at ...
  10. [10]
    [PDF] IMSA CODE - FIA Historic Database
    Fuel Capacity-. Maximum: 6 galions. Approved safety fuel cells are recommended and will become mandatory in near future. 10.6 IMSA SEDANS. 1. Purpose. The ...Missing: early | Show results with:early
  11. [11]
    [PDF] 1974 IMSA RS Comp Rules
    Safety fuel cells are mandatory. Maximum size is 22 gallons capacity. Quick fill fuel fillers and breathers may be installed and bodywork modified ...
  12. [12]
    [PDF] RMVR Exceptions and Clarifications to the 1976 IMSA Competition ...
    A roll-cage having a minimum of 8 chassis mounting points as shown in Appendix 12.2 of the. 1976 IMSA competition rules is required for all cars. The ...
  13. [13]
    1972 Watkins Glen IMSA | Motorsport Database
    1972 Watkins Glen IMSA · Sunday, September 10, 1972 · Camel 500 kms · IMSA Camel GT Championship.
  14. [14]
    A Decade after Merger Announcement, IMSA Continues Arcing Higher
    Sep 2, 2022 · The announcement joining GRAND-AM and ALMS came Sept. 5, 2012, setting the North American Sports Car Sanctioning Body on a path to new heights.Missing: acquisition | Show results with:acquisition
  15. [15]
    ALMS: Porsche wins Sebring as Audi and Peugeot falter - Autoweek
    Mar 16, 2008 · ALMS: Porsche wins Sebring as Audi and Peugeot falter ... Timo Bernhard helped pilot the Penske Porsche RS Spyder to the overall victory at the 12.Missing: rivalry | Show results with:rivalry
  16. [16]
    ALMS Returns to Natural Order: Rule change hands advantage from ...
    Jul 17, 2007 · A rule change robbed Porsche's LMP2-class RS Spyder of about 5 percent of its horsepower, handing the advantage back to Audi's LMP1 R10. Overall ...Missing: rivalry | Show results with:rivalry
  17. [17]
    2010 / Intercontinental Le Mans Cup - Racing Years
    Schedule of the 2010 Intercontinental Le Mans Cup season and the final standings.
  18. [18]
    Audi pulls out of the ALMS - Autoweek
    Dec 4, 2008 · Audi said on Friday that it will not be represented by its factory team, Audi Sport North America, in the 2009 American Le Mans Series.Missing: withdrawals | Show results with:withdrawals
  19. [19]
    Hagerty Becomes IMSA's Newest Corporate Partner
    Feb 24, 2020 · Today, IMSA is the sanctioning body of the IMSA WeatherTech SportsCar Championship, the premier sports car racing series in North America.Missing: affiliation | Show results with:affiliation
  20. [20]
    Does NASCAR Own IMSA? Details About the ... - The SportsRush
    Jan 29, 2024 · The answer would be yes. The IMSA was sold to NASCAR in 2012, and today, despite the ownership, both these series operate independently of each other.
  21. [21]
    [PDF] 2025 TECHNICAL REGULATIONS IMSA VP RACING SPORTSCAR ...
    Nov 22, 2024 · FIA Technical List #23: Roll Cage Padding Homologated by the FIA b. SFI Specification 45.1: Roll Cage Padding i. Specification ii ...Missing: affiliation | Show results with:affiliation
  22. [22]
    John Doonan Named IMSA President
    John Doonan has been named the next president of the sanctioning body effective January 1, 2020 with his first day on the job scheduled for Monday, Oct. 21.
  23. [23]
    IMSA, with NASCAR ties, motors on. QNA with president John Doonan
    Oct 27, 2024 · IMSA operates as its own entity but is a NASCAR property, headquartered in Daytona Beach. The organization draws particular interest and oversight from Bill ...
  24. [24]
    [PDF] 2025 IMSA OPERATIONAL CONTACT LIST
    Jan 8, 2025 · MEDICAL LIAISON. RYAN MCLEAN. MANAGER, MEDICAL LIAISON. (p) 386-310-6052. Pre-event medical planning, driver medical history review, ...Missing: divisions | Show results with:divisions
  25. [25]
    2025 IMSA State of the Sport Notebook | dailysportscar.com
    Oct 9, 2025 · IMSA President John Doonan hinted at the possibility of additional full-season and Michelin Endurance Cup entries for the 2026 WeatherTech ...Missing: expansions sustainability
  26. [26]
    Expanded Rolex 24 Grid “Not Possible” Due to Pit Lane Space
    Oct 27, 2025 · IMSA President John Doonan said it's currently “not possible” to accommodate more cars for the Rolex 24 at Daytona not only due to pit lane ...Missing: sustainability | Show results with:sustainability
  27. [27]
    IMSA Holds State of the Sport Address; Reveals 2026 WeatherTech ...
    Oct 9, 2025 · Michelin will sponsor a new sustainability award for the GTP class that will start in Daytona next year. As part of the annual announcement, the ...
  28. [28]
    IMSA: Sustainability
    The Official Motor Oil of the IMSA WeatherTech SportsCar Championship and IMSA Michelin Pilot Challenge is Focused on Developing Eco-Friendly Lubricants.Missing: grid expansions
  29. [29]
    weathertech sportscar championship the classes - IMSA
    These two styles of cars make up the series' four classes – Grand Touring Prototype (GTP), Le Mans Prototype 2 (LMP2), GT Daytona Pro (GTD PRO) and GT Daytona ( ...
  30. [30]
    WeatherTech: 2025 Schedule - IMSA
    Roar Before The Rolex 24. Jan 17 - Jan 19. Daytona International Speedway ; Rolex 24 At DAYTONA. Jan 22 - Jan 26. Daytona International Speedway ; Mobil 1 Twelve ...2026 Schedule · WeatherTech: 2024 Schedule · Roar Before The Rolex 24 · TV
  31. [31]
    IMSA Honors its Best at WeatherTech Night of Champions
    Oct 13, 2025 · – After a thrilling 2025 IMSA WeatherTech SportsCar Championship capped off by record-setting attendance at Motul Petit Le Mans, champions took ...
  32. [32]
    NBC Sports To Present More than 160+ Hours of 2025 IMSA ...
    Jan 16, 2025 · NBC Sports will present more than 160 hours of IMSA coverage in 2025, headlined by the IMSA WeatherTech SportsCar Championship, across NBC, Peacock, and USA ...
  33. [33]
    IMSA gets best TV viewership in over a decade as racing ...
    Oct 30, 2025 · Peacock data was not shared, but IMSA says its viewership in the 18-34 demographic was up 11% this season on linear TV. Related Story. 'F1 ...
  34. [34]
    Honda, Tequila Patrón ESM Wins the Rolex 24
    Feb 1, 2016 · Tequila Patrón ESM prevailed Sunday in a hard-fought Rolex 24 at Daytona, scoring Honda's first overall victory at the famed event and the first ...
  35. [35]
    Changes Shine Through in Refreshed 2025 IMSA Lineups at Daytona
    Feb 5, 2025 · The 61-car grid looked to start the 2025 IMSA WeatherTech SportsCar Championship versus the end of the 2024 campaign.
  36. [36]
    IMSA Announces 2025 Schedules for WeatherTech Championship ...
    Mar 15, 2024 · The BMW M Endurance Challenge will kick off the season for the Grand Sport (GS) and Touring Car (TCR) classes on Friday, Jan. 25.
  37. [37]
    imsa michelin pilot challenge the classes
    The Michelin Pilot Challenge has two different classes, Grand Sport (GS) and Touring Car (TCR). 2025 Impc Gs 124x35. Grand Sport. 2025 Gs Blank 621w. The Grand ...
  38. [38]
    IMSA's 2025 Challenge Series Champions Highlight Future ...
    Oct 15, 2025 · The theme of champions in both series in 2025 was the strong blend of both. In Michelin Pilot Challenge, 45-year-old veteran Jan Heylen and 19- ...
  39. [39]
    Michelin Becomes Official Tire of IMSA
    Jan 16, 2019 · Michelin North America is now the official tire of the International Motor Sports Association, which celebrates its 50th anniversary in 2019.
  40. [40]
    IMSA & Michelin Partnership
    Since becoming Official Tire of IMSA in 2019, Michelin has captured research and development data from over one million miles in competition by covering all ...
  41. [41]
    Ferrari Challenge Series: Corse Clienti - Ferrari.com
    Divided into 2 continental series (Europe and North America) and three Regional (UK since 2019, Japan from 2023 and Australasia from 2025), the Ferrari ...
  42. [42]
    Ferrari Challenge: Latest News | IMSA
    All Titles in Ferrari Challenge North America Series Are Still in Play, With the Two Races at Mugello Set to Decide the Champions. FIND OUT MORE.
  43. [43]
    Ferrari 296 Challenge | Corse Clienti
    A passenger seat can be installed if the driver wants support on the track from an instructor or to treat a guest to the thrill of a lap aboard the 296 ...
  44. [44]
    Ferrari Challenge North America Releases 2025 Schedule
    Jul 15, 2024 · Ferrari Challenge North America revealed its schedule for the 2025 season, featuring familiar venues from 2024, in addition to an exciting new addition and a ...Missing: IMSA | Show results with:IMSA
  45. [45]
    New Ferrari Challenge Season Begins at Sonoma - IMSA
    Mar 6, 2025 · Another season of Ferrari Challenge North America is set to begin at Sonoma Raceway and for 2025, the Ferrari 296 Challenge racecar has attracted a staggering ...
  46. [46]
    Ferrari Challenge Schedule 2025 - Conquest Racing
    Sep 15, 2025 · March 5-9. Sonoma, CA ; April 9-13. Daytona, FL ; May 14-18. Miami, FL ; June 25-29. Indianapolis, IN ; July 23-27. Watkins Glen, NY.
  47. [47]
    Ferrari Challenge Looks Ahead to WeatherTech Raceway Laguna ...
    Sep 10, 2025 · Laguna Seca marks the last of six races for Ferrari Challenge in North America this year, before the 296 Challenge racecars head to Finali ...
  48. [48]
    Ferrari Corse Clienti - Home | Ferrari.com
    News, videos and photos of Ferrari Corse Clienti activities around the world. Everything you need to know about our cars, teams and drivers.Ferrari Challenge Series · Cars · Sport Prototipi Clienti · Race CalendarMissing: support | Show results with:support
  49. [49]
    IMSA and Ferrari Challenge North America announce three-year ...
    Jan 24, 2015 · ... Ferrari Challenge under IMSA sanction in North America through the 2017 season. Established in 1993, and now in its 22nd year, Ferrari ...
  50. [50]
    [PDF] 2025 IMSA Official Schedule and SR Daytona 24H 011525 V1
    Jan 15, 2025 · Daytona Beach, FL 32114. 9.4.7 -. Length of the Racetrack: 3.56 mile, Speedway Road Course. 9.4.9 -. Direction of the Race: Counter-Clockwise.
  51. [51]
    ROLEX 24 - Daytona International Speedway
    This 24-hour marathon tests the limits of both driver and machine, setting the stage for the IMSA WeatherTech Sports Car Championship season.Rolex 24 at daytona camping · 2026 rolex 24 hospitality options
  52. [52]
    Daytona International Speedway | IMSA
    The new course for the stock cars measured 2.2-miles with a longer 4.1-mile course for the motorcycles. Both courses shared the same south turn. In 1953, France ...
  53. [53]
    TRACK HISTORY - Sebring International Raceway
    First 12 Hours of Sebring race held on March 15. 1953. The 12 Hours of Sebring is the first event of the new FIA sports car world championship. A Chrysler ...
  54. [54]
    12 Hours of Sebring
    For much of Sebring's history, the track followed a 5.2-mile layout. After a disastrous 1966 12 Hours the track was widened and lengthened 50 yards for 1967 ...
  55. [55]
    Sebring International Raceway: Stats and Facts - HOT ROD
    May 24, 2023 · The first 12 Hours of Sebring endurance race was held on March 15, 1952. ... The track's current configuration spans 3.74 miles, and the lap ...
  56. [56]
    WeatherTech Raceway Laguna Seca | IMSA
    The Corkscrew's elevation change makes it a one-of-a-kind turn in motorsports. In a distance of just 450 feet the elevation drops 59 feet, and continues to drop ...
  57. [57]
    Six Reasons to Love WeatherTech Raceway Laguna Seca - IMSA
    May 9, 2023 · Laguna Seca features 180 feet of elevation change, 59 of it coming in the space of a very famous 450-foot stretch of pavement known as the ...
  58. [58]
    https://www.imsa.com/news/2025/09/10/ferrari-challenge-looks-ahead-to-weathertech-raceway-laguna-seca/
  59. [59]
    2025 Circuit of The Americas - VPRC - IMSA
    Race Events. Entry List. Circuit of The Americas. Circuit Length: 3.426 miles. Entries by Class: Event Schedule. Friday, February 28, 2025. 1:00 PM to 1:40 PM ...
  60. [60]
    Circuit of The Americas - COTA - Visit Austin
    At its heart is a 3.41-mile racetrack that was designed to challenge the world's most exacting competitors while providing a thrilling spectacle for audiences.
  61. [61]
    International Motor Sport Association - World Sports Racing Prototypes
    Feb 14, 2007 · The International Motor Sport Association was founded in 1969. They organized one race that year. In 1971 the first whole IMSA season consisted ...
  62. [62]
    IMSA Archives - International Motor Racing Research Center
    The 12 Hours of Sebring became the first IMSA Camel GT event of the 1973 season. With the help of RJR's Joe Camel advertising campaign and renewed interest in ...Missing: launch | Show results with:launch
  63. [63]
    IMSA Comes To Project Motor Racing
    Sep 10, 2025 · And then came 1973 when the FIA pulled out of the Sebring event at the very last moment and gave IMSA a perfect opportunity to launch. With ...<|separator|>
  64. [64]
    The Old Men's Return: Porsche 944 in the Firehawk Series - Stuttcars
    The series was called the Firestone Firehawk Series, as the spec tires were supplied by Firestone and were the Firehawk high-performance road tires. Many ...
  65. [65]
    A Brief History of Street Stock Endurance Racing | 1985-2010 | Articles
    Oct 21, 2020 · The Firehawk series lasted for nearly a decade, and many of the same teams and drivers who are still involved with street stock racing ran in ...
  66. [66]
    IMSA Firehawk Series - The Racing History Project
    IMSA Firehawk Series. Racing History Project 1985. Racing History Project 1986. Racing History Project 1987. Racing History Project 1988
  67. [67]
    Golden Era of Street Stock Series Road Racing Announced as ...
    Mar 7, 2025 · It was formed in the mid-1970s with an inaugural event at Road Atlanta and became a part of International Motor Sports Association (IMSA) in ...<|separator|>
  68. [68]
    IMSA Supercar - Championships - Racing Sports Cars
    ### Summary of IMSA Supercar Championship (1990-1993)
  69. [69]
    1993 IMSA Bridgestone Supercar Series | Laguna Seca Sprint Race
    Apr 26, 2025 · The Bridgestone Tire Supercar Series was designed for more exotic road cars like the Porsche 911 (964 Generation) Turbo, Lotus Esprit X180R, ...
  70. [70]
    IMSA Supercar - final positions and tables
    1993 - IMSA Bridgestone Supercar Championship · 1. Hans-Joachim Stuck (D), Porsche 911 Turbo · 2. Doc Bundy (USA), Lotus Esprit X180R · 3. Andy Pilgrim (GB), Lotus ...Missing: history 1990-1993<|control11|><|separator|>
  71. [71]
    Renault Cup Racing: The IMSA Racing Series Time Forgot
    Mar 9, 2019 · The Renault Cup sprang from the desire to create a showroom stock series that would be cheap enough to attract an enormous number of competitors and create ...
  72. [72]
    Tribute to IMSA celebrates almost 50 years of racing - Autoweek
    Apr 18, 2017 · John Bishop founded IMSA in 1969. But that's a vast oversimplification. There was a lot more going on in the years leading up to -- and in ...
  73. [73]
    A Look at the Fascinating History of IMSA Racing - FanBuzz
    Aug 7, 2021 · For example, the International Sedan Series spawned the Radial Sedan Series, which eventually led to the Showroom Stock Series, which ...
  74. [74]
    IMSA At 50: Part One, Overview & The 1970s - dailysportscar.com
    Jun 25, 2019 · It was 50 years ago last Sunday, June 23, 1969, when the articles of incorporation for the International Motor Sports Association were filed ...
  75. [75]
    5 Chapters from the Life of Don Panoz, Automotive Titan - IMSA
    Aug 5, 2020 · Don Panoz came with his checkbook ready in 1999 to purchase the entire series. Founded by John and Peggy Bishop in 1959, the International Motor ...
  76. [76]
    How Panoz transformed sportscar racing - Motorsport.com
    Sep 14, 2018 · His creation of the American Le Mans Series for the 1999 season was the greatest achievement of his 20-odd year involvement in motorsport ...
  77. [77]
    Op-Ed – A Pro Mazda Carol: Part I, History of Star Mazda
    Dec 15, 2012 · Gary Rodrigues formulated a plan for the creation of the Star Mazda Series with the first race cars rolling off the line in the fall of 1990.Missing: acquisition | Show results with:acquisition
  78. [78]
    Pro Mazda Series renamed to Indy Pro 2000 - AutoRacing1.com
    Dec 12, 2018 · Originally debuting as Star Mazda in 1991, then reformed as Pro Mazda in 2013 when Andersen Promotions took over the helm after the previous ...<|control11|><|separator|>
  79. [79]
    Throwback Thursday: Top 10 Winningest Drivers on Continental Tires
    Sep 27, 2018 · In 2013, the final ALMS season, Continental Tire became the exclusive supplier for the series' Prototype Challenge (PC) class. When the ...
  80. [80]
    IMSA At 50: Part 5, The 2010s - dailysportscar.com
    Aug 11, 2019 · Prototype (P) The headline class for the series would feature a mix of Daytona Prototypes from GRAND-AM and LM P2 prototypes from the ALMS.
  81. [81]
    Atlantic Championship, IMSA announce agreement - Motorsport.com
    Jun 23, 2008 · IMSA TO SANCTION COOPER TIRES PRESENTS THE ATLANTIC CHAMPIONSHIP. A key component of the 35th anniversary season for the Cooper Tires ...
  82. [82]
    New Atlantic Championship Series formed - Autoweek
    Dec 15, 2011 · Formula Race Promotions has created the Atlantic Championship Series for SCCA-legal Formula Atlantic race cars, the promoter said on Thursday.Missing: 2009-2011 | Show results with:2009-2011
  83. [83]
    History Beckons for IMSA Competitors Racing the 2025 24 Hours of Le Mans | IMSA
    ### Summary of IMSA History from https://www.imsa.com/discover-imsa/history/
  84. [84]
    As A Decade Passes, Memories Last for Past IMSA Winners at Le ...
    Jun 13, 2025 · In 2025, they'd all be celebrating the 10-year anniversary of either their overall or class wins at the 24 Hours of Le Mans they achieved in 2015.
  85. [85]
    [PDF] LMDh-Technical-Regulations-2023.01.18_blackline.pdf - IMSA
    Jan 18, 2023 · These regulations set out the technical requirements for cars to be eligible to compete in the LMDh sportscar events organized by the ACO ...
  86. [86]
    IMSA Full-Season Grid Heavily Represented in 2025 Le Mans Entry ...
    Mar 3, 2025 · Porsche Penske claimed its spot by capturing the 2024 Grand Touring Prototype (GTP) class championship. Meanwhile Boulle and Fidani were the top ...
  87. [87]
    24 Hours of Le Mans 2025 - Porsche Motorsport Hub
    The Porsche Penske Motorsport team will field three Porsche 963s, with customer racing team Proton Competition running one. Manthey Racing will run three ...
  88. [88]
    GTP Homologation Is the Race within the Race - IMSA
    Nov 15, 2022 · The goal of LMDh homologation is for the participating manufacturers to receive final technical approval soon for the cars they will field when ...Missing: affiliation | Show results with:affiliation
  89. [89]
    Heart of Racing Team Aston Martin GTP, GTD Entries Confirmed for ...
    Oct 8, 2024 · The Heart of Racing Team will return to IMSA WeatherTech SportsCar Championship competition in 2025 with two entries once again.Missing: OEM | Show results with:OEM
  90. [90]
    Genesis Plans to Join WeatherTech Championship GTP Class in 2027
    Dec 4, 2024 · Genesis confirmed its plan to join the Grand Touring Prototype (GTP) class of the IMSA WeatherTech SportsCar Championship beginning in 2027 with the brand's ...
  91. [91]
    IMSA is attracting more manufacturers, and in turn, more fans - ESPN
    Jan 22, 2025 · Representing IMSA's vast GT categories is James Sullivan, co-owner of the championship-winning Vasser Sullivan Lexus operation he co-owns with ...<|separator|>
  92. [92]
    Porsche Carrera Cup North America Travels North of the Border for ...
    Jun 11, 2025 · Porsche Carrera Cup North America travels north of the border in conjunction with Formula 1® during the Grand Prix du Canada in Montréal.
  93. [93]
    IMSA secures long-term extensions with three entitlement partners
    Oct 12, 2023 · “WeatherTech is extremely proud to extend our partnership with IMSA through 2030 as the series entitlement sponsor,” said David MacNeil, Founder ...
  94. [94]
    Rolex and IMSA Finalize Long-Term Partnership
    Oct 10, 2024 · Rolex has been named as the new Official Timepiece of IMSA as part of a long-term partnership beginning in 2025.
  95. [95]
    IMSA and Michelin Finalize Long-Term Partnership Extension ...
    Oct 9, 2025 · The agreement ensures Michelin is planned to continue as the “Official Tire of IMSA” through the 2035 season. “Michelin has been an exceptional ...
  96. [96]
    Meet the Full Field for the 2025 Rolex 24 At Daytona - IMSA
    Jan 22, 2025 · Sixty-One Cars Are on the Grid for the 63rd Running of the Endurance Classic.
  97. [97]
    Meet the Full Field for the 2024 Rolex 24 At Daytona - IMSA
    Jan 24, 2024 · Fifty-Nine Cars Are on the Grid for the 62nd Running of the Endurance Classic. DAYTONA BEACH, Fla. – The complete field of cars for the 62nd ...