Dirt track racing
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|Dirt track racing|
Dirt track racing is a type of auto racing performed on oval tracks. It began in the United States before World War I and became widespread during the 1920s and 30s. Two different types of racecars predominated—open wheel racers in the Northeast and West and stock cars in the South. While open wheel racecars are purpose-built racing vehicles, stock cars (also known as fendered cars) can be either purpose-built racecars or street vehicles that have been modified to varying degrees.
Dirt track racing is the single most common form of auto racing in the United States. There are hundreds of local and regional racetracks throughout the nation: some estimates range as high as 1500. The sport is popular in Australia and Canada also. Some of the cars may also race on asphalt short tracks during the racing season.
Contrary to the common name, most dirt tracks are actually clay surfaced, rather than dirt.
- 1 The racetrack
- 2 The race vehicle
- 2.1 Open wheel cars
- 2.2 Modified cars
- 2.3 Full-bodied cars
- 2.4 Motorcycles
- 2.5 Vintage racing
- 3 The race program
- 4 Championships
- 5 See also
- 6 References
- 7 External links
Nearly all tracks are oval and less than 1-mile (1.6 km) in length with most being ½ mile (804 m) or less. The most common increments in the U.S. are ½ mile, ⅜ mile (603 m), ⅓ mile (536 m), ¼ mile (402 m), and ⅛ mile (201 m). The most common size track is 3/8 mile. With the longer tracks, the racecars achieve higher speeds and the intervals between cars increases. This decreases the chance of crashes but increases the damage and chance of injury when cars do crash.
The track surface may be composed of any soil, but most racers prefer a track with a clay base. The track operators usually try to keep the surface tacky and may sprinkle water on it if it becomes too dry. Some operators build flat circles, but many are highly banked.
In Great Britain the oval tracks are normally on grass with lengths of 400 meters (¼ mile) to 800 meters (½ mile). The race consists of several qualifying heats, each lasting four laps of the track leading up to the final.
Grass track is very much a family sport suitable for all ages and abilities. Boys and girls from as young as six can compete on automatic machines. The ages and capacity classes progress right through to adult status. There are also classes in youth grass track to run motocross machines. Youth events are carefully controlled to provide good racing for the competitors.
Rest of Europe
In mainland Europe, long tracks can be grass, sand or cinder, and can be up to 1-kilometer (0.62 mi) long.
The race vehicle
Each racetrack or sponsoring organization maintains a rule book outlining each class of racecar; including dimensions, engine size, equipment requirements and prohibitions. The requirements for each class are usually coordinated with other racetracks and associations to allow for the widest available venue for each type of car. This coordination allows the drivers to compete at many different racetracks, increasing their chances of winning, allows the racetrack to field as many cars as possible and lets the racing associations develop a series of race events and promote fan interest.
Many fans prefer one or the other of the different type cars. Open wheel fans prefer the higher speeds that the lightweight cars provide, while stock car (shown right and above) fans tend to enjoy more contact-oriented racing.
Many tracks support both types of racer in their programs. Both types range from large and powerful V8 engines to small yet still powerful, four-cylinder engines. Some of the smaller open wheel racers have classes for single-cylinder engines. Depending on the class, the cars may have wings to aid in handling at higher speeds.
Open wheel cars
Open wheel cars are generally manufactured with tubular frames and a body purchased for that particular class. Classes include:
- Dwarf (5/8 replicas of 1928 to 1948 coupes and sedans)
- Kart (go kart)
- Micro sprint
- Mini Sprint
- Silver crown
- Midget (Speedcar)
- Three Quarter Midget (TQ)
- Quarter midget
Open wheel sanctioning bodies include:
Modified cars are a hybrid of open wheel cars and stock cars - this class of car has the racing characteristics of a stock with the rear wheels covered by fenders and the front wheels open. There are sanctioning bodies that control the rules for this class at most tracks. Each sanctioning body has their own set of guidelines provided in an annual rule book and their own registration fees. Sanctioning bodies include:
- Advance Auto Parts Super Dirt Series
- IMCA (International Motor Contest Association)
- UMP (United Midwestern Promoters)
- USRA (United States Racing Association)
- USMTS (United States Modified Touring Series)
- WISSOTA (WISSOTA Promoters' Association)
- TSMA (Tri-State Modified Association)
Full-bodied cars, sometimes referred to as stock cars, are vehicles that, unlike open-wheel cars, have fenders covering all wheels. Full-bodied cars can vary from full tube frame chassis and aluminum bodied late models to automobiles manufactured by the major automakers with certain modifications as allowed for each class. There are several general types:
These are stock cars custom built for racing, usually with welded tubular frames and custom built or purchased bodies.
The most popular type of dirt full-bodied stock cars are late models. They are categorized depending on what track and series that is being run. The racetrack dictates what type of late model is raced, but most fall into one of these categories:
Today’s current dirt super late models feature steel constructed tube frame chassis with aluminum bodies that give them the sleek aerodynamic appearance of a stock race car but there is nothing stock about these 2300 pound machines. The cars are powered by an 850 horsepower (630 kW) motor than can turn in excess of 9,000 RPM. The engines are based on V-8 Chevy, Ford, and MOPAR power plants. These cars are considered to be the most sophisticated cars in dirt racing. They hit speeds well over 100 mph and slide around the dirt corners. They are raced on dirt tracks throughout the country anywhere from 1/4 to 1/2 mile.
The expense for these cars is extremely high. The cost for one complete race-ready late model is around $70,000. There is also cheaper equipment and parts that can be purchased, but staying competitive is much more expensive. To get the frame (chassis) and parts all new without the transmission and motor is around 20,000 to 30,000 dollars depending on the quality and from which manufacturer the chassis comes. The manufacturers around the country include Rocket, Bloomquist, GRT, Victory Circle, Warrior, Rayburn, Mastersbilt and Swartz Race Cars. The engines for these cars are around 850 horsepower and can cost up to 40,000 dollars. Motor builders include Hatfield Racing, Roush Yates Racing Engines, Gaerte Racing Engines, Clements Racing Engines, Custom Racing Engines, Vic Hill Racing Engines and Pro Power Engines.
Most racing series and special events offer different motor options with the use of different total vehicle weights to create an even playing field:
- Open motor - there is no displacement limit with this type of motor. Most open motors exceed 400 cubic inches but the 380 small block is also a common open motor. These motors utilize aluminum blocks and heads and often have specially welded cams. The cars which run this motor option must weigh at least 2,300 lb (1,000 kg).
- Spec motor- spec motors are built to the series' specifications. The motor can be either all-steel, all-aluminum or a combination. Spec motors typically cannot exceed 358 cubic inches. Cars using this motor option weigh in at 2200 pounds and run a 10-inch (250 mm) or 12-inch (300 mm) spoiler.
- All steel motor - steel block and heads, a maximum of 362 cubic inches, and weigh in at either 2200 or 2150 pounds depending on the series. Cars with an all-steel motor must run a 10-inch (250 mm) or 12-inch (300 mm) spoiler.
Limited late model
Limited late models and late model stocks have the same body rules as super late models. The main difference in the two classes is the motor rules. Engine limitations typically include maximum engine displacement size, certain required cylinder head angles, maximum compression ratios, and maximum carburetor size. Suspension rules typically forbid the use of expensive canister shocks. Tire choice is also typically limited to a certain tire such as the Hoosier D55 Spec Tire.
Late model stock
Late model stocks have the same body rules as super late models and limited late models. This class typically has even more limited engine rules.
Typical late model stock engine requirements:
- Chevrolet 350, Chrysler 360, Ford 351 engines. Must be all-steel except intake manifold.
- Engine maximum displacement of 362 cubic inches.
- Engines typically cannot be modified except for aftermarket carburetor, intake manifold and exhaust manifold.
Many different tracks and sanctioning bodies have variations on these rules of what constitutes an open late model, limited late model and a late model stock.
Crate late models
Crate late models use GM sealed-crate motors. Typical motors include the GM 602 and GM 604 engines. Recently the GM CT525 crate has been getting the attention of racers. Crate engines are sealed at the intake manifold, cylinder head, front cover, and oil pan with special twist off bolts. Crate engines must not be altered, modified, of changed in any way from factory specifications.
Crate late models have two of their own national touring series: the Nesmith Chevrolet Dirt Late Model Series and the Fastrak Crate Late Model Series.
Currently, Ford and Chrysler have no plans to enter the Nesmith or Fastrak Late Model Series.
Popular Late Model Racing Series
- The National Dirt Racing League
- World of Outlaws Late Model Series
- Lucas Oil Late Model Dirt Series
- Southern All Star Racing Series
- International Motor Contest Association (IMCA)
- United Midwestern Promoters (UMP)
- Advance Auto Parts Super Dirt Series
- Southern Regional Racing Series
- Advanced Auto Parts Thunder Series
- Southern United Professional Racing (SUPR)
- United Speed Contest Sanction
- Mid America Racing Series (MARS)
- Midwest Late Model Racing Association (MLRA)
- United Late Model Association (ULMA)
There are literally hundreds of additional unsanctioned regional and national special events run throughout the year.
Major annual late model events
Modified production cars
These cars are modified manufactured automobiles. There is a high degree of variability between classes of modified cars. The lowest divisions of modified production cars may be completely stock except for having their interior or windshields removed. The highest divisions of modified production cars may have only a few original stock parts, and may be nearly as fast as late model racecars. Most cars have their glass windshields removed and their interiors stripped out. The original seat may be allowed to be used in the lowest classes, but a racing seat and roll cage is required to be installed in higher divisions. Other safety and performance features are added to higher division cars. The engines in lower divisions are completely stock, and higher divisions are highly modified and enhanced. Most modified production cars use full exhaust systems. Engines vary from unmodified 4 cylinders to highly modified V8. Cars in lower divisions use stock tires, and higher division cars use purpose-built specified racing tires.
Common names of modified production car divisions:
Unmodified production cars
These cars are automobiles just as driven on the street; including the original interiors. The engines may be modified as allowed under different rules:
Dirt and Grass Track bikes have capacities of 250, 350, 500 and in the solo classes and can reach speeds of up to 80 mph (130 km/h) on the straights and with no brakes fitted to the machine. The American Grand National dirt track championship uses motorcycles of up to 750 cc capacities and can reach speeds of up to 130 mph (210 km/h).
There are three sidecar classes. The continental class has a 500 cc single-cylinder engine, also in Great Britain there are left- and right-handed sidecar machines with the engines up to 1000 cc. Sidecar races are some of the most exciting in Grass Track sport, with the driver and passenger working together to obtain the best grip and speed around the corners.
Many obsolete race vehicles that were left in barns to rust are being restored to their former glory. The restored race vehicles are being displayed at car shows and sometimes raced. Cars that compete in vintage racing events are from the late 19th century to historic cars from a few years ago. There are more than 170 racing events in North America, and thousands of other vintage events sanctioned by hundreds of clubs.
The race program
The typical race program usually involves a number of classes, and many tracks offer both open wheel and stock car racing. There is a wide variety of event formats.
A qualifying session may happen before the start of the event. The Lucas Oil Dirt Late Model Series and the World of Outlaw Late Models use the qualifying system to line up their heat races. They give each driver 2 timed laps to get their times. This system is also used to line up the big crown jewel events. For most of the regional series they use the method called the "pill draw." Before the races each driver draws a number and that determines where they start in their heat race.
Preliminary races for each class, called heat races, frequently open the schedule. The heat races may determine the starting race position in the main events and usually earn season championship points. The heat races are shorter than the feature races, and not as many cars race in each heat, from 8 to 12 laps for a heat race. There are numerous formats for qualifying for the feature event.
In a race where they qualify to determine their starting position for the heat race they use a "heads up" system. This system is where there is a predetermined set of cars that go to the A feature from the heat race, usually either the top 3 or 4.
In a race where they use the pill draw to line up the heat races they use a method called passing points. In this system a driver receives a set number of points for where they finish, 1st-59 2nd-57 and so forth the lower you finish. To add to the points the driver gets where you finish the driver also gets 1.5 points for each car they pass. Example: The driver starts 4th and finishes 1st. He gets 59 points for 1st and he passed 3 cars so he gets 4.5 extra points, so his total is 63.5. They will then usually take the top 16 drivers with the highest total amount of points and line up the A feature.
There may be a semi-feature where unqualified racers may race their way into the remaining open starting positions in the A feature event. This race is called the last chance qualifier or B feature. The cars who didn't make the A feature through the heat race get one more chance to qualify for the A feature through the B feature. The B is anywhere from 12 to 15 laps. Depending on how many B's there are determines how many transfer to the A, anywhere from 2 to 6 will transfer. If a driver transfers through the B they will start behind the drivers who made it through the heats.
The A feature or main feature race is held for each division. The top cars from the event compete in the race. The starting positions may be determined by the season's point standings, or by a combination of the heat/trophy dash/semi-feature finishing positions. It is usually the longest race in the program. Points, a trophy, and frequently a purse are generally awarded, with the amount of each is determined by finishing position. The winner of the feature event is considered the winner of the event.
Many tracks have other special events. Occasionally, a track will sponsor a "powder-puff" race to allow women the opportunity to drive the racecars for a few laps of racing. If enough women drivers express an interest in a separate event for themselves, the track operator may put the powder puff into its regular race schedule; otherwise, most serious women racers compete in the same events as the men.
From time to time, the track may have a "bonus points" race to attract racers and fans from competing tracks. Many times the track operators also promise a larger purse for winning these races.
Also, many tracks contract with a touring racing association to schedule an association sanctioned event. The racers in these events earn points for ranking in the association. The associations also usually require a guaranteed purse from the tracks for the winners of sanctioned events.
Many tracks also have a "run-what-you-brung" contest (also "Spectator class/division"). The event features two drivers from the stands who, after signing waivers, can run their personal automobiles against each other in a one-on-one 1 or 2 lap shootout.
Dirt tracks tend to be somewhat more makeshift and more versatile than asphalt pavements, and can be converted for use in other motorsports. For instance, Little Valley Speedway in Little Valley, New York is a half-mile dirt track that can be converted into a figure-8 track, a demolition derby pit, or a tractor pull straitaway.
Both the racetracks and the racing associations award championships as determined by the guidelines of the associated rulebooks. Awards, usually for the top ten racers in each class, may include a trophy, a jacket, and a monetary amount.
Track championships are awarded according to the points earned during the season. A certain number of points may be awarded for participation in an event and additional points added depending on the finish position in each race. The points earned at one track do not generally count toward another track's championship.
At dirt tracks sanctioned by NASCAR, drivers can compete against drivers from other NASCAR-sanctioned tracks, both paved and dirt, for the statewide and provincial Whelen All-American Series championship, where the best performer of the state and provincial champions will win the national championship. Dirt late model drivers won NASCAR's first such championship in 1982, and these drivers have frequently won regional and national championships in the 30-year history of NASCAR's short track championship, which only applies for local racing divisions (non-touring).
The racing associations count points earned at the tracks for certain sponsored races similarly. Additionally they may promote the appearances of their drivers and winners at various other events.
- A.M.A. Grand National Championship
- Dirt track
- List of Dirt Track Ovals in the United States
- National Dirt Late Model Hall of Fame
- "The First Sixty Years; An Illustrated History of the American Motorcyclist Association". American Motorcyclist (Books.Google.com). January 1984. Retrieved 1 January 2011.
- "Ridin' To The Races". American Motorcyclist (Books.Google.com). August 1978. Retrieved 1 January 2011.
- To Get Started Racing at Victory Lane Magazine