Drag racing

Drag racing is a form of auto racing in which cars or motorcycles attempt to complete a fairly short, straight and level course in the shortest amount of time, starting from a dead stop. Drag racing originated in the United States and is still the most popular there. The most common distance is one quarter of a mile (402 m), although one-eighth of a mile (201 m) tracks are also popular. The dragstrip extends well beyond the finish line to allow cars to slow down and return to the pit area.

Drag racing strategies and methods

The various strategies used in drag racing begin with the car itself. Performance enhancements must comply both with NHRA/IHRA rules and restrictions based on the class the car is running in. Some common enhancements include the use of slicks (smooth, soft tires that grip the track), methods for introducing more air into the motor such as turbos, superchargers, and nitrous oxide, specialized fuels (higher octane gas, methanol, alcohol, etc...), improved suspensions, and a multitude of others.

Related Topics:
NHRA - IHRA - Nitrous oxide - Methanol - Suspension

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The burnout

When approaching the starting line (also known as the staging area in drag racing), most racers will apply water to the rear tires either by backing into a small puddle or having it sprayed on. The car then exits the water and does a burn-out to heat the sticky tires, making them even stickier. Some cars have a "line-lock" which prevents the rear brakes from engaging when the brake pedal is depressed (which can be toggled on and off). This allows the car to remain stationary (with the brakes applied) without burning up the rear brake pads while doing a burn-out. Cars in street classes (which must be street legal) are the only exception to this pre-race ritual, as the grooved tires tend to retain some of the water.

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Staging

After the burn-out comes the "staging phase", where the cars pull up to the starting line. Each lane has its own christmas tree (discussed below) which has two small orange lights on top of it. These two lights are referred to as the pre-staged and staged lights. The two cars will slowly creep forward until the first (pre-staged) orange light is lit. This means they are very close to the actual starting line (a mere 7 inches). Then the cars will nudge forward until the second (staged) light is lit. This indicates they are at the official starting line. When both cars have lit both bulbs, the starter will begin the christmas tree.

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The nitrous purge

Only cars running nitrous oxide can do this. The drivers push a button that activates a solenoid called a purge valve, which clears the nitrous in the line out into the atmosphere without entering the motor. This allows compressed air that accumulates in the line out of the system and pulls the liquid nitrous towards the motor, ensuring a correct mixture of nitrous and fuel when the system is activated.

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The start

The christmas tree, as it is referred to in drag racing (also known simply as a "tree"), is a series of vertical lights. Generally, the top 3 are amber, then comes the green below that, with a red light at the bottom (often offset to the right slightly). There are two types of christmas trees, a normal one (also known as a "full tree") and a "pro tree". In a race using a normal tree, once the starter hits the engage button, the orange lights will come on, one at a time, beginning with the top one. The amber lights counting down to the green are timed .5 seconds apart. Normal trees are used for non-national events and casual local drag races. The pro tree, once the starter engages it, will display only the three amber lights at once for .4 seconds before the green is displayed. Pro trees are more difficult to anticipate and are the norm in major and national events.

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The main goal off the starting line is to go (known as "leaving") as close to when the light turns green as possible, without leaving too soon. If a car leaves before the light turns green, the red light will come on and should his opponent not commit a major foul, is disqualified (known as "red-lighting"). In case of a double red-light foul, if the Christmas tree system was not activated by the starter, both cars are disqualified. If the amber lights had been lit and the start lights were activated, and both cars leave before the light turns green, only the car which leaves first is charged with a red light. The opponent is given an automatic green light even if his reaction time is illegal. The time between when the green light comes on and the car actually leaves is known as the "reaction time". Reaction times are not factored into the time it takes a car to go from start to finish, but are important. For example, with two cars that run identical times, the car with the faster reaction time will win.

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Another important consideration when leaving is traction, especially in the faster classes. Doing a burn-out ("smoking the tires") at any point down the track costs precious time, as the car will lose acceleration. Some of the extremely high power cars will tune their vehicles to use less power early on (especially right off the line), as this is when there is the most danger of smoking the tires.

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Another possible problem is the car gets such excellent traction that the front wheels actually come off the ground and the car begins to rise into the air on its back tires (called a "wheelie"). In drag racing, this is a problem for five reasons. First, with the front wheels in the air, there is a loss of steering ability. Secondly, if the car rises too high in this manner, driver visibility is reduced. Thirdly, energy is wasted pushing the car into the air that would be better used pushing it down the track. Fourth, it is possible for the rear end of a car to scrape the track during wheelies. The answer to this problem is "wheelie-bars", which are simply two sturdy metal bars attached to the rear underside of a car with small wheels on the end. These wheels sit very close to the track at the back of the car (they actually extend past the rear of the car somewhat), and should it begin to rise, will make contact and prevent the car from rising further. Finally, especially in the dragster classes, where wheelbases can reach 300 inches, the combination of maximum traction, power application, and failure of the wheelie bars to limit upward movement of the nose of the car, on-rushing air may "blow-over," crashing the now upside down vehicle to the track surface.

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The rest of the race

Several things are important on the way down the track in drag racing. The first is not to cross into your opponent's lane, as this will result in disqualification. In case of a double disqualification in which one driver commits a foul start and the second driver crosses into his opponent's lane, the driver who committed the foul start wins. Another important consideration is when to shift gears on the way down. Most drag cars are shifted manually by the driver, and there are optimum times for shifting that vary with each car. Typically, power will increase as the engine RPMs (revolutions per minute) increase, but only up to a point before power begins to taper off. The ideal time to shift is at the peak power point. Most drag racers use a tachometer, which measures RPMs, to judge when to shift.

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Strategies for crossing the finish line usually only involve bracket racing (see above). If one car has a huge lead, it may slow down before crossing the finish line to ensure it doesn't "run out" and exceed its dial-in. Especially in casual street class bracket racing, it is not uncommon to see the leading vehicle's brake lights come on briefly before the finish line.

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If both cars "break out" and exceed their dial-in, the car closer to their dial-in wins. In NHRA Junior Dragster racing, however, there is a maximum elapsed time where a car which is faster than the maximum permissable time is ejected from the entire race. This is faster than the official break out elapsed time.

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