Formula 500 in 2012

Formula 500 (F500)[1] 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), and is a closely regulated class. Several chassis manufacturers produce different designs to a tight dimensional ruleset. Engines are specified by the ruleset, and builders are not allowed to modify engine internals. Instead of traditional dampers and springs, F500 cars utilize a very simple elastomeric spring medium contained in a cylindrical canister. The rules state the elastomer must be 2" in diameter by 1" in thickness, but the design and implementation of the elastomeric springs (commonly called "pucks" by the competitors) is wide open. Additionally, each chassis manufacturer produces bodywork of their own design, which adheres to dimensional constraints. These regulations allow for very competitive racing at a relatively low cost, which rewards driver and car set-up skills.

F500 engines

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

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, 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 Rotax 494 engine is a 499cc 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. The Rotax 494 went out of production for Ski-Doo following the 2000 model year. Ski-Doo/Rotax ended support for it shortly thereafter. Some parts however, are still available through dealers and online outlets.

In 2004 SCCA added the Rotax 493[2] to the list of approved engines. The 493 has the same bore and stroke as the 494. However, 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. Like the 494, the 493 also went out of production for Ski-Doo following the 2003 model year. Support for it ended in 2007. As with the 494, some parts are still available through dealers and online outlets.

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. The 593 remains in production for Ski-Doo to date, rebadged from "500ss" to "600" in 2010.

In 2021 SCCA allowed the use of the rotax 593HO or high output.

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 simple 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.

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 Track Champion 2nd Place 3rd Place Pole Position
F440 1984 Road Atlanta Michael Leathers Danny King Ray Little Danny King
F440 1985 Road Atlanta David W. Elliott Danny King Nick D'Amico David W. Elliott
F440 1986 Road Atlanta Michael Leathers David W. Elliott Brad Hulings David W. Elliott
F440 1987 Road Atlanta Michael Leathers David W. Elliott Brad Loehner David W. Elliott
F440 1988 Road Atlanta Dave Drissel Brad Loehner Paul Elliott Brad Loehner
F440 1989 Road Atlanta David W. Elliott Dave Drissel Michael Leathers David W. Elliott
F440 1990 Road Atlanta Paul Elliott David W. Elliott Brad Hulings Wesley Wilfong
F440 1991 Road Atlanta Paul Elliott David W. Elliott Chris Shultz Paul Elliott
F440 1992 Road Atlanta Chris Shultz Mike Brent Paul Elliott David W. Elliott
F440 1993 Road Atlanta Greg Grennan Paul Elliott Rusty Cook David W. Elliott
F440 1994 Mid-Ohio David W. Elliott James Martin Elder Rusty Cook Aaron Ellis
F440 1995 Mid-Ohio Ramon Partida Tim Tibbals Ron Vince Andy Lally
F440 1996 Mid-Ohio Jack Bennett Wesley Wilfong Howell C. Jones III Jim Hale
F500 1997 Mid-Ohio Mike Brent Wesley Wilfong David Lapham Mike Brent
F500 1998 Mid-Ohio Ron Vince David Lapham Wesley Wilfong Jeff Auberger
F500 1999 Mid-Ohio Jeff Auberger Mike Brent David Mitsch Aaron Ellis
F500 2000 Mid-Ohio Aaron Ellis Jim Schultz Rusty Cook Fred Edwards, Jr.
F500 2001 Mid-Ohio Elivan Goulart Jeff Jorgenson Calvin Stewart Thomas Edwards
F500 2002 Mid-Ohio Elivan Goulart Doug Marsh Kenny Price Elivan Goulart
F500 2003 Mid-Ohio Jonathan Dick Brian Novak Rusty Cook Doug Marsh
F500 2004 Mid-Ohio Jonathan Dick Aaron Ellis Jason Morales Doug Marsh
F500 2005 Mid-Ohio Doug Marsh Wiley McMahan Mike Brent Mike Brent
F500 2006 Heartland Park Bryan Golay David Cox Steven Jondal Jason Knuteson
F500 2007 Heartland Park Brian Novak Jason Knuteson James F. Libecco Jason Knuteson
F500 2008 Heartland Park Jason Knuteson Aaron Ellis David Lapham Jason Knuteson
F500 2009 Road America Jason Knuteson Patrick Gallagher Aaron Ellis Patrick Gallagher
F500 2010 Road America Patrick Gallagher Michael Mueller David Lapham Jason Knuteson
F500 2011 Road America Michael Mueller Jeremy Morales C.J. McAbee Michael Mueller
F500 2012 Road America Michael Mueller C.J. McAbee Mike Vacek Jason Knuteson
F500 2013 Road America James Weida Aaron Ellis Steve Jondal James Weida
F500 2014 Laguna Seca Brian Novak Wiley McMahan Jeff Jorgenson Brian Novak
F500 2015 Daytona Calvin Stewart Matthew Strand James Weida Wiley McMahan
F500 2016 Mid-Ohio Steven Thompson Brian Brothers Tom Diehm Calvin Stewart
F500 2017 Indianapolis Wiley McMahan Sven de Vries Steven Thompson Wiley McMahan
F500 2018 Sonoma Lance Spiering F Russell Strate Jr John W Walbran Jeff Jorgenson
F500 2019 VIR Wiley McMahan Calvin Stewart Eric McRee Wiley McMahan
F500 2020 Road America Wiley McMahan James Weida Calvin Stewart Calvin Stewart
F500 2021 Indianapolis Sven de Vries Ryan Mayfield Calvin Stewart Ryan Mayfield
F500 2022 VIR Sven de Vries James Weida Eric McRee James Weida


  1. ^ "Formula 500 - Videos". Sports Car Club of America. Retrieved 2022-03-02.
  2. ^ "[F500] 493 Rotax". Retrieved 2022-03-02.

External links

  • Non-commercial and most active online forum dedicated to the current SCCA Formula 500 class. Includes category specific technical forums dedicated to engines, chassis, and CVT tuning. As well as general, news, event specific, and classifieds forums.
  • Archived 2019-01-21 at the Wayback Machine Formula 500 community run by Contains information pertaining to current happenings, technical info, how-to's, event news and a classifieds section
  • The Formula 500 Racing Web Archived 2020-02-20 at the Wayback Machine 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.