These are the series that were formerly run by the IMSA organization.
IMSA GT Championship American Le Mans Series IMSA IS The
International Sedan Series was short-lived and the genesis of the
Radial Sedan Series. It is unclear if the 1969 inaugural IMSA Sedan race held at the
Talladega Superspeedway Road Course was designated
International Sedan Series or not. That being the only race held in 1969 details are sketchy, but over the winter of 1969–70 rules were officially promulgated for this Series. It was initially to be known as the
International 100 Series as it was intended for sedans up to 100 c.i or 1600 cc., however was revised prior to the start of the 1970 season to include larger engines and presumably the name change to
International Sedan Series. The next year, 1971, the Series was revamped and became the
Radial Sedan Series with the revolutionary innovation of requiring DOT radial tires. New rules allowed for cars over 1.6 L divided between two classes. Class A was for Sedans under 2 L., except for overhead cam engines which were limited to 1.6 L. Class B was for larger engines up to whatever IMSA decided appropriate for the Class which was the
AMC Gremlin's 232 c.i. for the duration of the 'original' RS Series. As an aside, the "Baby Grand" moniker frequently applied to these IMSA Series was just that, a nickname. Around this same time a series that was officially designated
Baby Grand (better and later known as the
Goody's Dash Series) was sanctioned by NASCAR and consisted of 4-cylinder cars purpose-built to run NASCAR ovals. A few RS regulars are known to have run both Series with the same car making minimal changes to accommodate the difference in rules. Carson Baird, driving a
Dodge Colt, was one of these 'crossover' competitors.
IMSA RS The
IMSA RS Series (for
radial sedan) began as the
Baby Grand Series, in 1971. Originally sponsored by
B.F. Goodrich (therefore known as
Goodrich Radial Challenge) until they dropped sponsorship midway through 1975 (or 1976) and then by
Goodyear (becoming the
Goodyear Radial Challenge), and later as
Champion Spark Plug Challenge. The initial race held was in 1969 at
Talladega Superspeedway Road Course. Gaston Andrey was first overall in an
Alfa Romeo Giulia Super sedan. The Series' first year was actually 1970 with only two races, the inaugural race was at the newly constructed
Summit Point Motorsports Park on Memorial Day weekend; Rasey Feezell was first overall in an
Alfa Romeo Giulia TI Super sedan; the second race was held at the
Montgomery Speedway, Alabama,
Red Farmer won in a specially prepared
Datsun 510. Feezell didn't fare too well having to drive against the local four-cylinder "beater class" cars brought in to fill out the field, with their protruding wheels rubbing Racey's "immaculate"
Alfa Romeo. Infuriated, Feezell quit and never ran another IMSA RS race after that. The idea was to attract racers who did not have the budgets that were required in the GT category as well as an emphasis on compact sedans such as the
AMC Gremlin and the
Opel Manta. There were two classes from 1970 through 1973: Class A for under two liters and under 1.6 liters with
overhead cam and Class B for over 1.6 L with overhead cam and over two liters up to the largest permitted engine being the AMC Gremlin. In 1974 all cars were placed in one class, with the only parity for the smaller engines being free
carburetion for under 1.6 liters. Limited preparation was permitted, and since the entrants were meant to be street-driven race cars, the original rules required the retention of headlights, seats, upholstery, window cranks, stock brakes and original springs and radial tires. Only the exhaust systems and shock absorbers were free. Later rules regarding headlights, seats, upholstery, window cranks, original springs, and other stock elements were loosened up somewhat. From the beginning, engine modifications similar to
Sports Car Club of America B Sedan were permitted, with the main difference being that over-boring cylinders was not allowed, and stock carburetors being required, but modifications allowed. The series was loosely based on rival SCCA
Trans-Am's Two-Five Challenge rules. The series became dominated mostly by
Mazda's
rotary-powered RX-2 and
RX-3 prompting IMSA to specify heavier weights than piston-engined cars and prohibited any modifications to the rotors and more importantly to intake and exhaust ports.
Datsun also had a fair share of success within the series with cars such as the
510 and
200SX. Many drivers would cut their teeth in this series such as Don Devendorf, of
Electramotive fame,
Jim Downing, of Kudzu, and
Bobby Rahal. The final season was run in 1984 before it was replaced by the
IMSA Showroom Stock class the following year, while retaining its sponsor until 1988. As with most now-defunct racing classes, there are revival races run for this category and the
SCCA sanctions events for mostly-stock and all-stock cars.
American Challenge The
American Challenge (in full,
Kelly American Challenge), otherwise abbreviated as
AAC was a category for US-built cars and throughout the series, it was always run as a support race to the premier GT series. Starting in 1977, the series ran until 1989. In 1992, the premier GTO category was renamed to GTS due to sponsor reasons, and rather than leaving the GTO category redundant, the title was reallocated to the former American Challenge cars. As a result, they would be run alongside GTS cars. This series started the careers of
Irv Hoerr,
Kenny Irwin Jr.,
Patty Moise,
Clay Young,
Lyn St. James and
Paul Gentilozzi.
IMSA Renault Cup The
Renault Cup was a
one-make racing series that ran between 1982 and 1985. There was an East Coast (1982–1985) and West Coast series (1983–1985) as well as an overall championship. The series began with the
Renault Le Car for two seasons on the East Coast until its discontinuation in the US. The last two seasons, the East Coast Series ran the
Renault Encore. The West Coast Series started after the first successful year on the East Coast, but ran the
Renault Alliance which had just been introduced. The genesis of the series was an association of drivers,
Associated Road Racers (ARR), founded by Steve Coleman of Raleigh, North Carolina. The association's objective was to start an inexpensive but competitive series with large car counts. The main prerequisite requirement was a series that would allow drivers who had regular jobs and a life to compete with at least a chance to win the championship without having to travel coast to coast, as was the case with other similar series such as the
VW Bilstein Cup. The preference was to have a roughly ten-race schedule, with each driver's best six finishes counting toward the Championship. ARR's members were mostly
Showroom Stock racers from the Southeast and Northeast
Sports Car Club of America (SCCA) regions. All members put up a bond to ensure they would participate if it came to fruition so that a sanctioning body and a sponsor would be assured success from the start. In the beginning an outline of series rules was drawn up to attract like-minded drivers to join in the effort. Once the association was formed, a final version was to be drafted with all the members' input. The rules along with the association's proposed plan to organize and launch the series, were sent to several manufacturers soliciting sponsorship, including
Mazda,
Toyota,
Nissan, and Renault. All except Renault either rejected the proposal or did not respond. Renault not only responded, it jumped at the chance, since it was quite familiar with the concept of a one-make series. ARR and Renault negotiated to finalize a format competing with the Le Car R5. Due to classic concerns of track owners and sanctioning bodies, Renault was reluctant to agree to the drivers' points system. Their counterproposal was to run an East Coast series in lieu of nationwide. Since most of the interested drivers were from the East Coast, and the amount of travel required was somewhat limited, this was accepted by the drivers. Once Renault was on board, John Bishop, President of IMSA, was approached to sanction the series. He was very skeptical at first. A meeting was held on at
Road Atlanta between Bishop, B Clar, the US Competition Director of Renault, and Coleman representing the drivers. Renault offered a major support program and ARR would guarantee a minimum of twenty-five entrants for the first race. Bishop, still skeptical, agreed to sanction the series. Coleman even suggested there might be as many as fifty, if Renault and IMSA didn't revise the proposed series rules to a point the majority of drivers would pull out before then. Still skeptical he agreed, convinced by Renault's commitment and the driver's assurances of a full field for the inaugural race. Exactly one year to the date on April 4, 1982, the inaugural race was held at
Road Atlanta. 51 Le Cars started the race. One notable driver to come from the series was
Parker Johnstone; he took runner-up spot on his debut season in 1984 and would virtually dominate the series following that.
IMSA Showroom Stock In 1985, IMSA would undergo a major rules reformat while still retaining its sponsor, therefore it was still known by its
sponsor's moniker. This time, the series was more restricted to current models, that is to say models then currently available for retail sale in dealerships throughout the US. Other than that, the series had rules and race formats that were similar to the RS series, being an endurance series. At the end of the 1987 season, Champion stepped down as sponsor and was replaced by
Firestone Tire and Rubber Company; therefore, the series was renamed
IMSA Firestone Firehawk Endurance Championship, commonly known as the
Firehawk Series, after the Firehawk performance tire brand. Total prize purses, year-end point funds and manufacturer contingency awards in 1991 amounted up to $1 million. As required by the sponsor, all cars were required to use its own Firehawk SZ or Firehawk SV tires which could be shaved to racing depth, or the all-season Firehawk GTX.
Bosch and Kendall Oil were also associate sponsors. Most of the drivers that competed in the series were amateurs or semi-professional, whilst a few made their living out of competing in the series.
Dorsey Schroeder and
John Andretti are among the few full-time professional drivers who cut their teeth in the series. Meetings usually attracted over ninety entries and were often televised, the duration of the races varying from one two hour and a half event to one 24 hour race. The series would soldier on until 1998, by then known as
Speedvision Cup, named for the former motosports-oriented television network. During the sportscar racing "split" from 1998 until 2013, a rival series from Canada, the Motorola Cup, was sanctioned by the SCCA, with Grand-Am taking over in 2001. This is the other series that led to the modern
Continental Tire Sports Car Challenge. There are three classes, sorted in order from the highest • Grand Sport Class •
Chevrolet Camaro,
Pontiac Trans Am,
Nissan 300ZX (twin-turbo),
BMW M3,
Ford Thunderbird,
Ford Mustang,
Porsche 944,
Mazda RX-7 (FC3S) • Sport Class •
Pontiac Sunbird Turbo,
Dodge Daytona Turbo II,
Honda Civic CRX Si,
Volkswagen Corrado • Touring Class, •
Honda Civic Si,
Audi 100 Quattro,
Pontiac Grand Am IMSA Bridgestone Supercar Championship IMSA also hosted the
Bridgestone Supercar Championship, sponsored by the sister brand of Firestone,
Bridgestone, which was for higher-end sports cars such as the
Porsche 911 Turbo,
Lotus Esprit X180R,
Chevrolet Corvette,
Mazda RX-7 and
Nissan 300ZX and was run between 1991 up until 1995. Usually a televised support race to the GT races, running at 30 minutes, the series attracted some well-known professional drivers such as
Hans-Joachim Stuck,
Hurley Haywood,
Doc Bundy,
Elliot Forbes-Robinson,
Andy Pilgrim and
Paul Newman. with a total prize fund of $555,555 for the 1992 season. All cars had to run on road-going Bridgestone Potenza RE71 tires which were trimmed to semi-racing depth and during a wet race, cars raced on full depth. The series was an invitational affair with forty one drivers are selected out of four hundred applicants to participate in the Women's Global GT Series. The grid would usually consists of experienced racers such as former
Formula One drivers,
Giovanna Amati and
Divina Galica, NASCAR's
Shawna Robinson, and Italian Audi factory team
touring car driver
Tamara Vidali against talented amateur drivers from varying degrees of professions, such as radio personality, police officer, law student, and racing simulations art designer for
Microsoft. Each class had an overall championship, a master's championship for drivers at least 40 years of age, and a team championship. In 2017 the series became the IMSA Prototype Challenge presented by Mazda, featuring
LMP3 cars and L1 cars re-branded as MPC (Mazda Prototype Challenge). In 2023, the series was replaced by the
IMSA VP Racing SportsCar Challenge, which featured
LMP3 and
GT4 in their respective classes with shorter race distances. ==References==