Formula 500
Encyclopedia
Formula 500 is a Sports Car Club of America
(SCCA) and Midwestern Council of Sports Car Clubs (MCSCC) open wheel
road racing
class.
Formula 500 was originally introduced in the early 1980s as Formula 440 (F440). Formula 500 is a spec class in the sense that the engine, drivetrain, and shock absorbers are all tightly regulated, but the chassis, bodywork and other car parts are free for designers to experiment with within dimensional and structural limits. These regulations allow for very competitive racing at a relatively low cost which rewards driver and car set-up skill.
494, or Rotax
493 originally produced for Ski-Doo
snowmobiles. Older cars, mostly used for Solo events these days use the Kawasaki 440/A engine. The AMW 500L-85/250-2 R2c engine, while legal for use in Formula 500 racing, is rarely used these days.
The Kawasaki 440/A engine, produced by Kawasaki Heavy Industries
, is a 436 cc piston port engine utilizing 38 mm Mikuni VM series carburetors and a tuned dual exhaust. While this engine is no longer competitive in road racing, it is still widely used in Solo II and Autocross
events. Like all F500 engines, except for the AMW, the Kawasaki was originally produced as a snowmobile engine. It has been out of production since the early 1980s. Parts for these engines are becoming more difficult to find.
The AMW 500L-85 engine, built by Two Stroke International was introduced to F500 in 1994. It is a 497 cc reed valve engine using twin 38 mm Mikuni SuperBN carburetors. To keep the performance of these larger, more powerful engines in line with prior engines, SCCA mandates the use of a spec Y exhaust manifold and single tuned pipe on the AMW engine. Unlike the other engines used in F500, the AMW engine is a derivative of a light aircraft engine. This engine is no longer in production, and is not supported by the manufacturer.
Introduced for the 1997 season was the Rotax 494 engine. Rotax
builds racing and industrial engines for a wide variety of applications, including aircraft, motorcycles, go-karts, snowmobiles and watercraft, The 494 cc Rotax engine is a rotary-valve engine. Like the AMW, the Rotax utilizes a 2 into 1 "Y" exhaust manifold and a single tuned expansion chamber
exhaust. The Rotax engine utilizes the same 38 mm Mikuni VM carburetors as the Kawasaki. The Rotax engine has become, by far, the most popular engine in F500 road racing. Though the Rotax 494 is now out of production, Rotax continues to support it and provide parts.
In 2004 SCCA added the Rotax 493 to the list of approved engines. The 493, unlike the 494, is a reed valve engine. It also runs Mikuni VM series carbs and the "Y" exhaust manifold like its cousin the 494. Cars running the 493 engine are required to run at a higher minimum weight to maintain parity with the older 494 and AMW engines.
In 2011 SCCA added the Rotax 593 to the list of approved engines. The 593, (more commonly known as the Ski-Doo 500ss) is a 600cc version of the reed valve 493 engine. It also runs Mikuni VM series carbs and the "Y" exhaust manifold like the other Rotax engines, but are required to run a specified intake restrictor to keep power output on par with the 500cc 493 engine. Cars running the 593 engine are also required to run at a higher minimum weight to maintain parity with the older 494 and AMW engines.
Engine specifications are tightly regulated by the SCCA. No engine modifications are permitted in formula 500. Engines must be run in stock form "as delivered" from the factory. No aftermarket parts, port modifications, or other variations from stock configuration are allowed. This helps keep costs down and means close competition on the track.
(CVT), similar to that used in snowmobiles.
These advanced belt driven automatic transmissions are tuned to optimize the power curve of a two-stroke engine, constantly keeping the engine at its peak power. One of the key benefits of the CVT is that it is a stepless transmission. This allows all of the engine's power to be transmitted to the drive wheels at all times. Another benefit is its low cost as compared to a traditional multi-gear transmission.
Sports Car Club of America
The Sports Car Club of America is a club and sanctioning body supporting road racing, rallying, and autocross in the United States. Formed in 1944, it runs many programs for both amateur and professional racers.-History:...
(SCCA) and Midwestern Council of Sports Car Clubs (MCSCC) open wheel
Open wheel car
Open-wheel car, formula car, or often single-seater car in British English, describes cars with the wheels outside the car's main body and, in most cases, one seat. Open-wheel cars contrast with street cars, sports cars, stock cars, and touring cars, which have their wheels below the body or fenders...
road racing
Road racing
Road racing is a general term for most forms of motor racing held on paved, purpose-built race tracks , as opposed to oval tracks and off-road racing...
class.
Formula 500 was originally introduced in the early 1980s as Formula 440 (F440). Formula 500 is a spec class in the sense that the engine, drivetrain, and shock absorbers are all tightly regulated, but the chassis, bodywork and other car parts are free for designers to experiment with within dimensional and structural limits. These regulations allow for very competitive racing at a relatively low cost which rewards driver and car set-up skill.
F500 engines
Formula 500 cars are powered by a two-cylinder, water-cooled two-stroke engine. Modern cars use either the RotaxRotax
BRP-Powertrain GmbH & Co KG , commonly known simply as Rotax, is an Austrian engine manufacturer. It develops and produces four-stroke and advanced two-stroke engines for Bombardier Recreational Products products as well as for motorcycles, karts,...
494, or Rotax
Rotax
BRP-Powertrain GmbH & Co KG , commonly known simply as Rotax, is an Austrian engine manufacturer. It develops and produces four-stroke and advanced two-stroke engines for Bombardier Recreational Products products as well as for motorcycles, karts,...
493 originally produced for Ski-Doo
Ski-Doo
Ski-Doo is a brand name of snowmobile fabricated by Bombardier Recreational Products. The first Ski-Doo was launched in 1959. It was a new invention Joseph-Armand Bombardier...
snowmobiles. Older cars, mostly used for Solo events these days use the Kawasaki 440/A engine. The AMW 500L-85/250-2 R2c engine, while legal for use in Formula 500 racing, is rarely used these days.
The Kawasaki 440/A engine, produced by Kawasaki Heavy Industries
Kawasaki Heavy Industries
is an international corporation based in Japan. It has headquarters in both Chūō-ku, Kobe and Minato, Tokyo.The company is named after its founder Shōzō Kawasaki and has no connection with the city of Kawasaki, Kanagawa....
, is a 436 cc piston port engine utilizing 38 mm Mikuni VM series carburetors and a tuned dual exhaust. While this engine is no longer competitive in road racing, it is still widely used in Solo II and Autocross
Autocross
Autocross is a form of motorsports that emphasizes safe competition and active participation. An autocross is a timed competition where drivers navigate one at a time through a defined course on either sealed or unsealed surfaces...
events. Like all F500 engines, except for the AMW, the Kawasaki was originally produced as a snowmobile engine. It has been out of production since the early 1980s. Parts for these engines are becoming more difficult to find.
The AMW 500L-85 engine, built by Two Stroke International was introduced to F500 in 1994. It is a 497 cc reed valve engine using twin 38 mm Mikuni SuperBN carburetors. To keep the performance of these larger, more powerful engines in line with prior engines, SCCA mandates the use of a spec Y exhaust manifold and single tuned pipe on the AMW engine. Unlike the other engines used in F500, the AMW engine is a derivative of a light aircraft engine. This engine is no longer in production, and is not supported by the manufacturer.
Introduced for the 1997 season was the Rotax 494 engine. Rotax
Rotax
BRP-Powertrain GmbH & Co KG , commonly known simply as Rotax, is an Austrian engine manufacturer. It develops and produces four-stroke and advanced two-stroke engines for Bombardier Recreational Products products as well as for motorcycles, karts,...
builds racing and industrial engines for a wide variety of applications, including aircraft, motorcycles, go-karts, snowmobiles and watercraft, The 494 cc Rotax engine is a rotary-valve engine. Like the AMW, the Rotax utilizes a 2 into 1 "Y" exhaust manifold and a single tuned expansion chamber
Expansion chamber
An expansion chamber is an exhaust system used on a two-stroke cycle engine to enhance its power output by improving its volumetric efficiency. It makes use of the energy left in the burnt exhaust exiting the cylinder to aid the filling of the cylinder for the next cycle...
exhaust. The Rotax engine utilizes the same 38 mm Mikuni VM carburetors as the Kawasaki. The Rotax engine has become, by far, the most popular engine in F500 road racing. Though the Rotax 494 is now out of production, Rotax continues to support it and provide parts.
In 2004 SCCA added the Rotax 493 to the list of approved engines. The 493, unlike the 494, is a reed valve engine. It also runs Mikuni VM series carbs and the "Y" exhaust manifold like its cousin the 494. Cars running the 493 engine are required to run at a higher minimum weight to maintain parity with the older 494 and AMW engines.
In 2011 SCCA added the Rotax 593 to the list of approved engines. The 593, (more commonly known as the Ski-Doo 500ss) is a 600cc version of the reed valve 493 engine. It also runs Mikuni VM series carbs and the "Y" exhaust manifold like the other Rotax engines, but are required to run a specified intake restrictor to keep power output on par with the 500cc 493 engine. Cars running the 593 engine are also required to run at a higher minimum weight to maintain parity with the older 494 and AMW engines.
Engine specifications are tightly regulated by the SCCA. No engine modifications are permitted in formula 500. Engines must be run in stock form "as delivered" from the factory. No aftermarket parts, port modifications, or other variations from stock configuration are allowed. This helps keep costs down and means close competition on the track.
F500 transmission
F500 uses an advanced Continuously Variable TransmissionContinuously variable transmission
A continuously variable transmission is a transmission that can change steplessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios...
(CVT), similar to that used in snowmobiles.
These advanced belt driven automatic transmissions are tuned to optimize the power curve of a two-stroke engine, constantly keeping the engine at its peak power. One of the key benefits of the CVT is that it is a stepless transmission. This allows all of the engine's power to be transmitted to the drive wheels at all times. Another benefit is its low cost as compared to a traditional multi-gear transmission.
External links
- Formula500.org Formula 500 community run by eformulacarnews.com. Contains information pertaining to current happenings, technical info, how-to's, event news and a classifieds section
- F500.us Online forum dedicated to the current SCCA Formula 500 class.
- The Formula 500 Racing Web Now inactive former unofficial home page of SCCA F500 racing. The archived mailing list is a good historical resource of information.
- The Sports Car Club of America is the major sanctioning organization that runs F500 races in the United States.
- Formula 500 on YouTube Joe Palmer's YouTube Channel of Formula 500 In-Car Videos, and Slideshows.