Mazda RX-792P
Encyclopedia
The Mazda RX-792P was a racing car built for the IMSA GT Championship
's GTP category for Mazda
. Its career was short lived, with only two cars running in 1992 before the project was abandoned.
The car's name would be a combination of Mazda's RX-7
road car, the year the car raced, and the fact that it was a prototype.
in IMSA's GTO class and MX-6
in the GTU class, Mazda chose to take on a new challenge. Although Mazda has supported the use of their rotary
engines in GTP prototypes in the past, Mazda wished to compete with the likes of Porsche
, Nissan, Jaguar
, and Toyota with a full factory effort. This would coincide with Mazda's continued running of the World Sportscar Championship
in Europe, as well as the All Japan Sports Prototype Championship
at home.
After Mazda's success in winning the 1991 24 Hours of Le Mans
, a change in engine rules by the FIA would force Mazda to abandon their R26B
4-rotor in the World Sportscar Championship. However IMSA rules continued to allow the use of rotaries, which led Mazda to bring the R26B to North America, with refinements to better suit the shorter races and circuits.
For a chassis, Mazda would use the expertise of Crawford Composites to construct their tub, while Fabcar would assist in the project. Due to the different style of racing, the new car would not share much from Mazda's previous effort, the 787B
and its predecessors. The tub would be built from carbon fiber
, while the bodywork designed by Lee Dykstra would feature new sweeping lines, including a large exposed vent flowing out from the front wheel well.
A total of three RX-792Ps would be built by Crawford for Mazda before the project was cancelled.
and Pete Halsmer
. Opting to skip the 24 Hours of Daytona
, the first chassis would appear at the Grand Prix of Miami. Unfortunately, a fire caused by the hot exhaust touching the car's bodywork would force the car to be withdrawn before the race even took place. This problem continued at the 12 Hours of Sebring
, where the car caught fire once again just prior to the race.
By the next round at Road Atlanta
, the second RX-792P chassis would be completed. Both cars were entered in the event, but an accident in practiced forced the second car to not run. The lone remaining RX-792P would manage to take the green flag, finishing in a distant 15th place, nearly twenty laps behind the winner. With the second chassis repaired, Mazda moved to Lime Rock Park
, where the cars would finally show their potential. After qualifying in the middle of the grid, the pair would come home in third and fourth places, three laps behind the winning Toyota. At Mid-Ohio
the RX-792Ps would finish sixth and ninth.
Problems crept up once again as the series moved to New Orleans, with one entry managing a mere 16th. However the Mazda team would quickly rebound to take their best finish of the season, with a second place at Watkins Glen
, even though this was actually five laps behind the winner. A follow-up seventh place at Laguna Seca
would unfortunately be followed by a double DNF at Portland
.
A quick rebound would see fourth and fifth places at Road America
before the team once again failed to finish either car at Phoenix
. This trend would continue at the final race of the season, as neither car would make it to the checkered flag. This string of bad results would leave Mazda a distant sixth in the constructor's championship, although Price Cobb would be able to finish eighth in the driver's championship.
and All Japan Sports Prototype Championship
would be cancelled, leaving Mazda's expensive MXR-01
nowhere to race. At the same time, IMSA announced plans to abandon the GTP category after the 1993 season, turning instead to a new category of open-cockpit prototypes. This meant that Mazda would only have one more year to be able to use the RX-792P in North America only before they would have to construct an all new car.
But the RX-792P effort was full steam ahead for 1993 and the group began to look towards improvements that could be made the chassis. On IMSA’s sliding weight vs. engine displacement scale the Mazda 4-rotor came in at 1750 lbs and many teams had cause for concern about this thinking the Mazda engine had been gifted a power-to-weight ratio advantage. While the RX-792P showed occasional turns of speed, the reality was that the engine simply was giving up far too much horsepower to its competitors thus making the perceived power to weight bias within the regulations just that; a perception and not a reality. And, any advantage that might have been was certainly offset for the need to cool the car and the corresponding drag relative to power output.
With that in mind Mazda was thinking about what could be done to close that power gap. Mazdaspeed supplied the program’s 4-rotor engines and had developments on the dyno in Japan that were producing 700+ hp. “Needless to say we were excited and looking forward to the 1993 season,” says Dick St. Yves, Mazda Motorsports Manager 1988-1993. Subsequently design mockups were underway to move the oil cooler into the side pods and enlarging the front mounted radiator. A program of weight reduction was also being considered as the car never scrutineered at its 1750 lb. minimum anyway, typically coming in around 75 lbs. above it.
The RX-792P program was done to an astonishingly small budget according to Dick St. Yves, “I have been told that Toyota’s budget was $20,000,000 and Nissan was in the area of $35,000,000, our budget was $5,000,000.” The program started in May 1991 to a vacant warehouse in Charlotte, North Carolina and by February 1992 the first car was assembled into these humble beginnings. The 4-rotor was giving up tremendous power as well, in the region of 200+, to its competitors. And while the regulations seemed give the Mazda a weight advantage, it certainly wasn’t able to bring that to bear. Considering year one a development year, as with all of the one-year wonders, year two certainly would have had much more to offer. Alas St. Yves relates that his 1993 budget had actually been approved by Mazda USA in October 1992 but for Mazda Corporation to announce a month later they were pulling out of racing, “The 4-rotor engine was the only component of the car that came from Japan. We were informed a few days later that they were discontinuing the experimental engine program, which was the 4-rotor, and that was the demise of the RX-792P program.” So with a budget, but no engines, that’s how it ended. By December 1992 the doors were closed.
IMSA GT Championship
IMSA GT was a sports car racing series organized by International Motor Sports Association. Races took place primarily in the United States and occasionally in Canada.-History:...
's GTP category for Mazda
Mazda
is a Japanese automotive manufacturer based in Fuchū, Aki District, Hiroshima Prefecture, Japan.In 2007, Mazda produced almost 1.3 million vehicles for global sales...
. Its career was short lived, with only two cars running in 1992 before the project was abandoned.
The car's name would be a combination of Mazda's RX-7
Mazda RX-7
Series 1 is commonly referred to as the "SA22C" from the first alphanumerics of the vehicle identification number. This series of RX-7 had exposed steel bumpers and a high-mounted indentation-located license plate, called by Werner Buhrer of Road & Track magazine a "Baroque depression."In 1980...
road car, the year the car raced, and the fact that it was a prototype.
Development
Following many successful years running the RX-7Mazda RX-7
Series 1 is commonly referred to as the "SA22C" from the first alphanumerics of the vehicle identification number. This series of RX-7 had exposed steel bumpers and a high-mounted indentation-located license plate, called by Werner Buhrer of Road & Track magazine a "Baroque depression."In 1980...
in IMSA's GTO class and MX-6
Mazda MX-6
The first generation MX-6 appeared in 1988 and lasted until 1992 in the United States. In some markets the model years were from 1987 to 1991. It was based on a series of futuristic sports compact concept cars of the early 1980s...
in the GTU class, Mazda chose to take on a new challenge. Although Mazda has supported the use of their rotary
Wankel engine
The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that...
engines in GTP prototypes in the past, Mazda wished to compete with the likes of Porsche
Porsche
Porsche Automobil Holding SE, usually shortened to Porsche SE a Societas Europaea or European Public Company, is a German based holding company with investments in the automotive industry....
, Nissan, Jaguar
Jaguar (car)
Jaguar Cars Ltd, known simply as Jaguar , is a British luxury car manufacturer, headquartered in Whitley, Coventry, England. It is part of the Jaguar Land Rover business, a subsidiary of the Indian company Tata Motors....
, and Toyota with a full factory effort. This would coincide with Mazda's continued running of the World Sportscar Championship
World Sportscar Championship
The World Sportscar Championship was the world series run for sports car racing by the FIA from 1953 to 1992.The championship evolved from a small collection of the most important sportscar, endurance and road racing events in Europe and North America with dozens of gentleman drivers at the grid,...
in Europe, as well as the All Japan Sports Prototype Championship
All Japan Sports Prototype Championship
The , abbreviated as JSPC, formed by the Japanese Automobile Federation, was a domestic championship which took place in Japan for Group C and IMSA GTP prototype cars and also featured cars that were eligible for touring car racing in its earlier years...
at home.
After Mazda's success in winning the 1991 24 Hours of Le Mans
1991 24 Hours of Le Mans
The 1991 24 Hours of Le Mans was the 59th Grand Prix of Endurance, and took place on June 22 and 23 1991. It was also the fourth round of the Sportscar World Championship.-Pre-race:...
, a change in engine rules by the FIA would force Mazda to abandon their R26B
Mazda Wankel engine
The Mazda Wankel engines are family of car engines derived from experiments in the early 1960s by Felix Wankel, a German engineer...
4-rotor in the World Sportscar Championship. However IMSA rules continued to allow the use of rotaries, which led Mazda to bring the R26B to North America, with refinements to better suit the shorter races and circuits.
For a chassis, Mazda would use the expertise of Crawford Composites to construct their tub, while Fabcar would assist in the project. Due to the different style of racing, the new car would not share much from Mazda's previous effort, the 787B
Mazda 787B
The Mazda 787 and its derivative 787B were Group C sports prototype racing cars built by Mazda for use in the World Sportscar Championship, All Japan Sports Prototype Championship, as well as the 24 Hours of Le Mans from 1990 to 1991...
and its predecessors. The tub would be built from carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...
, while the bodywork designed by Lee Dykstra would feature new sweeping lines, including a large exposed vent flowing out from the front wheel well.
A total of three RX-792Ps would be built by Crawford for Mazda before the project was cancelled.
Racing history
Managed by Mazda Motorsports, the first RX-792P would be completed shortly before the 1992 season would begin. The team would consist of drivers Price CobbPrice Cobb
Price Cobb won the 1990 24 Hours of Le Mans together with John Nielsen and Martin Brundle in a Jaguar XJR-12. He also owned an Indy Racing League team in 1998 and 1999 for Roberto Guerrero and Jim Guthrie...
and Pete Halsmer
Pete Halsmer
Pete Halsmer , is a former driver in the CART Championship Car series. He raced in 5 seasons , with 33 career starts, and started in the Indianapolis 500 in 1981-1982. He finished in the top five three times in the CART series, with his best finish in 2nd position in 1983 at Cleveland...
. Opting to skip the 24 Hours of Daytona
24 Hours of Daytona
The 24 Hours of Daytona, currently known as the Rolex 24 Daytona for sponsorship reasons, is a 24-hour sports car endurance race held annually at Daytona International Speedway in Daytona Beach, Florida. It is run on a combined road course, utilizing portions of the NASCAR tri-oval and an infield...
, the first chassis would appear at the Grand Prix of Miami. Unfortunately, a fire caused by the hot exhaust touching the car's bodywork would force the car to be withdrawn before the race even took place. This problem continued at the 12 Hours of Sebring
12 Hours of Sebring
The 12 Hours of Sebring is an annual motorsport endurance race for sports cars held at Sebring International Raceway, a former Army Air Force base in Sebring, Florida...
, where the car caught fire once again just prior to the race.
By the next round at Road Atlanta
Road Atlanta
Road Atlanta is a 2.54-mile road course located just north of Braselton, Georgia, USA. The facility is utilized for a wide variety of events, including professional and amateur sports car and motorcycle races, racing and driving schools, corporate programs and testing for motorsports teams...
, the second RX-792P chassis would be completed. Both cars were entered in the event, but an accident in practiced forced the second car to not run. The lone remaining RX-792P would manage to take the green flag, finishing in a distant 15th place, nearly twenty laps behind the winner. With the second chassis repaired, Mazda moved to Lime Rock Park
Lime Rock Park
Lime Rock Park is a natural-terrain motorsport road racing venue located in Lime Rock, Connecticut, United States, a hamlet in the village of Lakeville, Connecticut, in the state’s northwest corner...
, where the cars would finally show their potential. After qualifying in the middle of the grid, the pair would come home in third and fourth places, three laps behind the winning Toyota. At Mid-Ohio
Mid-Ohio Sports Car Course
Mid-Ohio Sports Car Course is a road course auto racing facility located in Troy Township, Morrow County, Ohio, United States, just outside of the village of Lexington...
the RX-792Ps would finish sixth and ninth.
Problems crept up once again as the series moved to New Orleans, with one entry managing a mere 16th. However the Mazda team would quickly rebound to take their best finish of the season, with a second place at Watkins Glen
Watkins Glen International
Watkins Glen International is an auto race track located near Watkins Glen, New York, at the southern tip of Seneca Lake. The facility is owned by International Speedway Corporation...
, even though this was actually five laps behind the winner. A follow-up seventh place at Laguna Seca
Mazda Raceway Laguna Seca
Mazda Raceway Laguna Seca is a paved road racing track used for both auto racing and motorcycle racing, originally constructed in 1957 near both Salinas and Monterey, California, USA....
would unfortunately be followed by a double DNF at Portland
Portland International Raceway
Portland International Raceway is located in Portland, Oregon, USA's, Delta Park complex on the former site of Vanport, just south of the Columbia River. It is west of a light rail station and less than a mile west of Interstate 5....
.
A quick rebound would see fourth and fifth places at Road America
Road America
Road America is a road course located near Elkhart Lake, Wisconsin on Wisconsin Highway 67. It has hosted races since the 1950s and currently hosts races in the NASCAR Nationwide Series , American Le Mans , SCCA Speed World Challenge Series, ASRA, and AMA Superbike series.- Current track and...
before the team once again failed to finish either car at Phoenix
Phoenix International Raceway
Phoenix International Raceway, also known as PIR, is a one-mile, low-banked tri-oval race track located in Avondale, Arizona. The track opened in 1964 and currently hosts two NASCAR race weekends annually. PIR has also hosted the Indycar Series, CART, USAC and the Rolex Sports Car Series...
. This trend would continue at the final race of the season, as neither car would make it to the checkered flag. This string of bad results would leave Mazda a distant sixth in the constructor's championship, although Price Cobb would be able to finish eighth in the driver's championship.
Cancellation
Following the 1992 season, sports car racing throughout the world was greatly altered. Both the World Sportscar ChampionshipWorld Sportscar Championship
The World Sportscar Championship was the world series run for sports car racing by the FIA from 1953 to 1992.The championship evolved from a small collection of the most important sportscar, endurance and road racing events in Europe and North America with dozens of gentleman drivers at the grid,...
and All Japan Sports Prototype Championship
All Japan Sports Prototype Championship
The , abbreviated as JSPC, formed by the Japanese Automobile Federation, was a domestic championship which took place in Japan for Group C and IMSA GTP prototype cars and also featured cars that were eligible for touring car racing in its earlier years...
would be cancelled, leaving Mazda's expensive MXR-01
Mazda MXR-01
The Mazda MXR-01 was a Group C sportscar used by Mazda's factory team Mazdaspeed in the 1992 World Sportscar Championship season. It would be the final Mazda entry in sportscars since the inception of their Le Mans project in 1983.-Development:...
nowhere to race. At the same time, IMSA announced plans to abandon the GTP category after the 1993 season, turning instead to a new category of open-cockpit prototypes. This meant that Mazda would only have one more year to be able to use the RX-792P in North America only before they would have to construct an all new car.
But the RX-792P effort was full steam ahead for 1993 and the group began to look towards improvements that could be made the chassis. On IMSA’s sliding weight vs. engine displacement scale the Mazda 4-rotor came in at 1750 lbs and many teams had cause for concern about this thinking the Mazda engine had been gifted a power-to-weight ratio advantage. While the RX-792P showed occasional turns of speed, the reality was that the engine simply was giving up far too much horsepower to its competitors thus making the perceived power to weight bias within the regulations just that; a perception and not a reality. And, any advantage that might have been was certainly offset for the need to cool the car and the corresponding drag relative to power output.
With that in mind Mazda was thinking about what could be done to close that power gap. Mazdaspeed supplied the program’s 4-rotor engines and had developments on the dyno in Japan that were producing 700+ hp. “Needless to say we were excited and looking forward to the 1993 season,” says Dick St. Yves, Mazda Motorsports Manager 1988-1993. Subsequently design mockups were underway to move the oil cooler into the side pods and enlarging the front mounted radiator. A program of weight reduction was also being considered as the car never scrutineered at its 1750 lb. minimum anyway, typically coming in around 75 lbs. above it.
The RX-792P program was done to an astonishingly small budget according to Dick St. Yves, “I have been told that Toyota’s budget was $20,000,000 and Nissan was in the area of $35,000,000, our budget was $5,000,000.” The program started in May 1991 to a vacant warehouse in Charlotte, North Carolina and by February 1992 the first car was assembled into these humble beginnings. The 4-rotor was giving up tremendous power as well, in the region of 200+, to its competitors. And while the regulations seemed give the Mazda a weight advantage, it certainly wasn’t able to bring that to bear. Considering year one a development year, as with all of the one-year wonders, year two certainly would have had much more to offer. Alas St. Yves relates that his 1993 budget had actually been approved by Mazda USA in October 1992 but for Mazda Corporation to announce a month later they were pulling out of racing, “The 4-rotor engine was the only component of the car that came from Japan. We were informed a few days later that they were discontinuing the experimental engine program, which was the 4-rotor, and that was the demise of the RX-792P program.” So with a budget, but no engines, that’s how it ended. By December 1992 the doors were closed.
External links
- Mulsanne's Corner - Mazda RX-792P
- Crawford Composites - Crawford history