|This article does not cite any references or sources. (January 2010)|
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 Rotax 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.
F500 transmission 
F500 uses an advanced Continuously Variable Transmission (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.
SCCA National Championship Runoffs History 
The SCCA National Championship Runoffs has crowned Formula 500 National Champions since 1997. The original Formula 440 class competed at the SCCA Runoffs from 1984 - 1996.
|Class||Year||Champion||2nd Place||3rd Place||Pole Position|
|F440||1984||Michael Leathers||Danny King||Ray Little||Danny King|
|F440||1985||David W. Elliott||Danny King||Nick D'Amico||David W. Elliott|
|F440||1986||Michael Leathers||David W. Elliott||Brad Hulings||David W. Elliott|
|F440||1987||Michael Leathers||David W. Elliott||Brad Loehner||David W. Elliott|
|F440||1988||Dave Drissel||Brad Loehner||Paul Elliott||Brad Loehner|
|F440||1989||David W. Elliott||Dave Drissel||Michael Leathers||David W. Elliott|
|F440||1990||Paul Elliott||David W. Elliott||Brad Hulings||Wesley Wilfong|
|F440||1991||Paul Elliott||David W. Elliott||Chris Shultz||Paul Elliott|
|F440||1992||Chris Shultz||Mike Brent||Paul Elliott||David W. Elliott|
|F440||1993||Greg Grennan||Paul Elliott||Rusty Cook||David W. Elliott|
|F440||1994||David W. Elliott||James Martin Elder||Rusty Cook||Aaron Ellis|
|F440||1995||Ramon Partida||Tim Tibbals||Ron Vince||Andy Lally|
|F440||1996||Jack Bennett||Wesley Wilfong||Howell C. Jones III||Jim Hale|
|F500||1997||Mike Brent||Wesley Wilfong||David Lapham||Mike Brent|
|F500||1998||Ron Vince||David Lapham||Wesley Wilfong||Jeff Auberger|
|F500||1999||Jeff Auberger||Mike Brent||David Mitsch||Aaron Ellis|
|F500||2000||Aaron Ellis||Jim Schultz||Rusty Cook||Fred Edwards, Jr.|
|F500||2001||Elivan Goulart||Jeff Jorgenson||Calvin Stewart||Thomas Edwards|
|F500||2002||Elivan Goulart||Doug Marsh||Kenny Price||Elivan Goulart|
|F500||2003||Jonathan Dick||Brian Novak||Rusty Cook||Doug Marsh|
|F500||2004||Jonathan Dick||Aaron Ellis||Jason Morales||Doug Marsh|
|F500||2005||Doug Marsh||Wiley McHahan||Mike Brent||Mike Brent|
|F500||2006||Bryan Golay||David Cox||Steven Jondal||Jason Knuteson|
|F500||2007||Brian Novak||Jason Knuteson||James F. Libecco||Jason Knuteson|
|F500||2008||Jason Knuteson||Aaron Ellis||David Lapham||Jason Knuteson|
|F500||2009||Jason Knuteson||Patrick Gallagher||Aaron Ellis||Patrick Gallagher|
|F500||2010||Patrick Gallagher||Michael Mueller||David Lapham||Jason Knuteson|
|F500||2011||Michael Mueller||Jeremy Morales||C.J. McAbee||Michael Mueller|
|F500||2012||Michael Mueller||C.J. McAbee||Mike Vacek||Jason Knuteson|
- 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.