Formula 500

Formula 500 (F500) 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.

Eric Christensen in a KBS Mk-8 at Phoenix International Raceway, January 1999

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

2009 National Runoffs winner

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

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.