Drag racing

Drag racing is a sport in which cars race down a track with a set distance as fast as possible.

While usually thought of as an American and Canadian pastime, drag racing is also very popular in Australia, New Zealand, Japan, the Caribbean in particular Aruba, Mexico, Greece, Malta, South Africa and Scandinavian countries especially Finland and Sweden. At any given time there are over 325 drag strips operating world-wide.

Drag races are an acceleration contest from a standing start between two vehicles side by side over a measured distance. The accepted standard for that distance is either a quarter-mile (1,320 feet) or an eighth-mile (660 feet). A drag racing event is a series of such two-vehicle, tournament-style eliminations. The losing driver in each race is eliminated, and the winning drivers progress until one driver remains.

These contests are started by means of an electronic device commonly called a Christmas Tree because of its multicolored starting lights. On each side of the Tree are seven lights: two small amber lights at the top of the fixture, followed in descending order by three larger yellow LED lights, a green bulb, and a red bulb.

Two light beams cross the starting-line area and connect to trackside photocells, which are wired to the Christmas Tree and electronic timers in the control tower. When the front tires of a vehicle break the first light beam, called the prestage beam, the pre-stage light on the Christmas Tree indicates that the racer is approximately seven inches from the starting line.

When the racer rolls forward into the stage beam, the front tires are positioned exactly on the starting line and the stage bulb is lit on the Tree, which indicates that the vehicle is ready to race. When both vehicles are fully staged, the starter will activate the Tree, and each driver will focus on the three large amber lights on his or her side of the Tree.

Depending on the type of racing, all three large amber lights will flash simultaneously, followed four-tenths of a second later by the green light (called a Pro Tree), or the three bulbs will flash consecutively five-tenths of a second apart, followed five-tenths later by the green light (called a Sportsman, or full, Tree).

Two Separate performances are monitored for each run: elapsed time (e.t.)and speed. Upon leaving the staging beams, each vehicle activates an elapsed-time clock, which is stopped when that vehicle reaches the finish line. The start-to-finish clocking is the vehicle's elapsed time, which serves to measure performance. Speed is measured in a 66-foot "speed trap" that ends at the finish line. Each lane is timed independently.

The first vehicle across the finish line wins, unless, in applicable categories, it runs quicker than its dial-in or index (see glossary). A racer also may be disqualified for leaving the starting line too soon, leaving the lane boundary (either by crossing the centerline, touching the guardwall or guardrail, or striking a track fixture such as the photocells), failing to stage, or failing a post-run inspection (in NHRA class racing, vehicles usually are weighed and their fuel checked after each run, and a complete engine teardown is done after an event victory).

The elapsed time of the vehicle is measured from when the front wheels run out of the staging beam until they cross the finish line; thus, a car with a faster elapsed time can actually lose the race if the driver does not react to the green light fast enough. The elapsed time is a measure of performane only; it does not, per se, determine the winner. In practice, it is necessary for the driver to "jump the gun" by a fraction of a second, starting the car during the split-second interval between when the yellow light goes out and the green light goes on. However, if the car leaves the front electric eye ("the beam") before the green light comes on, the driver has "red-lighted" (because the red light is lit on the Christmas Tree) and should no further fouls happen during the race, is disqualified. Once a driver commits a red-light foul, the green light is automatically signaled on the other side, even if the other driver also commits a foul start by leaving the line too early. A driver who gets a substantial lead at the start is said to have gotten a "holeshot", and in a heads-up start, should he have a slower elapsed time and wins the race, has a "holeshot win". The driver's reaction time and the car's top speed are also recorded, in addition to the e.t., on the "timeslip". The car that crosses the finish line first wins. A car can actually blow an engine part way down the strip and coast to the end of the track at a (relatively) lower top speed than the competitor, and still win with a lower elapsed time. This practice, where both drivers leave at the same time, is called "heads-up racing", and is used in all professional ("pro") classes.

In the common Eliminator racing format, the losing car and driver are removed from the contest, while the winner goes on to race other winners, until only one is left. There are some instances where there are three cars remaining, and in this case one car, either chosen at random or the car with the fastest elapsed time thus far, gets a "bye run" where his or her car goes down the track by itself (in order to at least partially eliminate the advantage that would otherwise come from the engine having one less run on it), and then awaits the winner of the other two for the title. However, in most Eliminator formats, the bye runs take place only in the first round. Drivers are about equally divided between making a nice easy pass on the bye run so as not to stress the car unduly, making a real effort for the benefit of the spectators, or recording a time good enough to earn lane choice. Unlike the NHRA, many European events will feature a consolation race where the losers of the semifinal rounds will race for third place, the final spot on the podium, and more points than the fourth-place driver.

During drag racing events, vehicles are classified into different classes by various criteria that take into account the extent of modifications to the car. These criteria include engine capacity, configuration of cylinders, frame type, vehicle construction materials, wheelbase, horsepower to weight ratio, number of cylinders, whether or not power adding devices such as turbochargers, superchargers or nitrous oxide are employed, vehicle type (such as car, truck, et cetera), or even make and model for limited entry fields. The aforementioned divisions are in place to ensure that the cars are evenly matched during the race.

Drag racing vehicles are special in that they are modified to be lighter and more powerful than in their standard form. A lighter vehicle means that the power-to-weight ratio is increased and hence a greater acceleration will be achieved. Power increases vary depending on the extent of the modifications to the engine.