Drag racing

From Academic Kids

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. 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, especially in the southeastern USA. The dragstrip extends well beyond the finish line to allow cars to slow down and return to the pit area.

While usually thought of as an American and Canadian pastime, drag racing is also very popular in Australia, New Zealand, Japan, the Caribbean, England, Greece, Malta and most European and Scandinavian countries. At any given time there are over 325 drag strips operating world-wide.

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A jet engine powered "Funny Car"


The origins of the sport lie in illegal street racing in the United States. The format of the sport shows these origins: two cars line up next to each other, and await a green light as the signal to start, just as if they were sitting next to each other at a stoplight. The straight course mimics the straight streets of most American cities. By the 1930s, hot-rodders had begun to race away from the roads, on Southern California's dry lake beds, and by the late 1940s, attempts to codify the sport were underway. The first drag strip opened on a Santa Ana, California airfield in 1950.

Southern California was the hot bed for development of the sport in the 1950s as various clubs organized races. "Hot Rod Magazine" and its editor, Wally Parks began to promote racing safety and standardization. The magazine sponsored national "Safety Safari" tours to spread drag racing to other parts of the country. The NHRA (see organization below) was founded as a national sanctioning body and Parks eventually left the magazine to head the organization.

Initially contests were between modified street vehicles, but over time racers got more innovative and classes proliferated to reflect the different approaches to achieving rapid acceleration.

Racing organization

Most (although not all) drag racing involves two cars racing each other to the end of the measured distance. The elapsed time from the light turning green to the car's front end passing through the 'traps' at the other end of the track determines the winner; this time is composed of the car's actual elapsed time, plus the driver's reaction time. In practice, in the more competitive classes it is necessary for the driver to 'jump the gun' by a faction 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 crosses the electric eye in front of it before the green light comes on, the driver has 'red-lighted' and is disqualified. A driver who gets a substantial lead over the other car taking off at the start is said to have a 'hole shot'. The driver's reaction time and the car's top speed are also recorded, in addition to the elapsed time, but neither plays a direct role in determining the winner. The car that crosses the finish line first wins the race. A car with a good hole shot can actually blow the engine partly 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.

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 instances where there are 3 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. Drivers are about equally divided between making a nice easy pass on the bye run so as not to stress the car unduly, or making a real effort for the benefit of the spectators.

The National Hot Rod Association (NHRA) oversees the majority of drag racing events in North America. The next largest organization, the International Hot Rod Association, (IHRA), is about one-third the size of NHRA. Nearly all drag strips will select one or the other of these sanctioning bodies to be associated with. The NHRA is more popular with large, 1/4 mile nationally-recognized tracks, while the IHRA is a favorite of smaller 1/8th mile local tracks. One reason for this (among others) is the IHRA is less restrictive in its rules and less expensive to be associated with.

There are literally hundreds of different classes in drag racing, each with different requirements and restrictions on things such as weight, engine size, body style, modifications, and many others. The NHRA and IHRA share some of these classes, but many are solely used by one sanctioning body or the other. The NHRA boasts over 200 classes, while the IHRA has fewer. There is even a class for aspiring youngsters - Junior Dragster.

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Top Fuel dragster. King of the Hill in drag racing. Get too close without ear protection and your ears will ring for days.

However, there are only 5 "professional" classes (4 NHRA, 4 IHRA), which are:

  • Top Fuel The rail dragsters, the fastest class. (NHRA and IHRA both)
  • Funny Car Nearly as fast as the rails, resemble actual cars. In the early nineties, IHRA got rid of the Top Fuel Funny Car category, making Top Alcohol Funny Cars the only funny car class in the IHRA. (NHRA and IHRA both)
  • Pro Modified Some engine restrictions, very high power. Cars can run superchargers or nitrous oxide. Cars running blowers are limited to 527 cubic inches (8.6 L) while cars with nitrous oxide can run up to 740 cubic inches (12.1 L). (IHRA only)
  • Pro Stock Must maintain stock appearance. NHRA cars can run no more than 500 cubic inches (8.2 L) while IHRA cars can run upwards of 800 cubic inches (13.1 L). (NHRA and IHRA both)
  • Pro Stock Bikes Heavily modified motorcycles. (NHRA only)

In addition to the above professional classes, these are some other popular classes:

A complete listing of all classes can be found on the respective NHRA and IHRA official websites (see external links).

To allow different cars to compete against each other, some competitions are raced on a handicap basis, with faster cars delayed on the start line enough to theoretically even things up with the slower car. This may be based on rule differences between the cars in stock, super stock, and modified classes, or on a competitor chosen "dial-in time" in bracket racing.

A "dial-in" is a time the driver estimates it will take his or her car to cross the finish line, and is generally displayed on one or more windows so the starter can adjust the "christmas tree" starting lights accordingly. The slower car will then get a head start equal to the difference in the two dial-ins, so that if both cars perform perfectly, they would cross the finish line dead even. If either car goes faster than its dial-in (called running out or breaking out), it is disqualified regardless of who has the lowest elapsed time; if both cars break out, the one who breaks out by the smallest amount wins. This eliminates any advantage from putting a slower time on the windshield to get a head start. The effect of the bracket racing rules is to place a premium on consistency of performance of the driver and car rather than on raw speed, in that victory goes to the car and driver which can precisely predict their elapsed time, whether it is fast or slow. This in turn makes victory much less dependent on large infusions of money, and more dependent on mechanical and driving skill. Therefore, bracket racing (using the aforementioned handicapping system) is popular with casual weekend racers. Many of these recreational racers will drive their vehicles to the track, race them, and then simply drive them home. Most tracks do not host national events every week, and on the interim weekends host local casual and weekend racers. Organizationally, however, the tracks are run according to the rules of either the NHRA or the IHRA (for the most part). Even street vehicles must pass a safety inspection prior to being allowed to race.

There is even an organization called the National Electric Drag Racing Association, (NEDRA), which races electric vehicles against high performance gasoline-powered vehicles such as Dodge Vipers or classic muscle cars in 1/4 and 1/8 mile races.

Drag racing performance facts

The fastest top fuelers can attain terminal speeds of over 330 mph (530 km/h) while covering the quarter mile (402 m) distance in roughly 4.5 seconds. It is often related that Top Fuel dragsters are the fastest accelerating vehicles on Earth; quicker even than the space shuttle launch vehicle or catapult-assisted jet fighter (however this ignores the rocket dragsters). In fact, if you take a vehicle traveling at a steady 200 mph (322 km/h) as it is crossing the start line, a top fuel dragster starting from a dead stop at the same moment will beat it to the finish line one quarter of a mile (402 m) away. Additionally, through the use of large multiple braking parachutes, the astounding performance of 0 to 330 mph (531 km/h) and then back to 0 in 20 seconds can be obtained.

The faster categories of drag racing are an impressive spectacle, with engines of over 6000 horsepower (4.5 MW) and noise outputs to match, cars that look like bizarre parodies of standard street cars (funny cars), and the ritual of burnouts where, prior to the actual timed run, the competitors cause their wheels to spin while stationary or moving slowly, thus heating up the tires and laying down a sticky coat of rubber on the track surface ( which may have been coated with VHT Trackbite or similar to increase traction) to get optimum grip on the all-important initial launch.

Drag-racing has traditionally been the domain of big - usually American - cars with high-capacity engines. However, the power to weight ratio of lighter, usually imported, cars has allowed them to be successful when their engines are modified and bodies lightened. The Volkswagen Beetle was one of the first to be exploited this way. Recently there has been an increase in what has been called (outside of Japan) "import drag racing", where smaller Japanese cars are raced. The somewhat derogatory term for these cars is "rice rockets". Use of a turbocharger or supercharger is very common, and often necessary to break through the 12-second quarter-mile barrier.

One of the negative side-effects of import drag-racing is that the cheaper cars involved are often raced (illegally) on the street, where they cause trouble, with many drivers making a public nuisance of themselves. Illegal import street-racing was glamorised in the movie The Fast and the Furious. This phenomenon is just a resurgence of the problem, which has existed ever since there have been cars and "hot-rodders" (cf. American Graffiti, Rebel Without a Cause, etc.).

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.

The burnout

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Example of a burn-out before staging. Note the amount of smoke.

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.


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.

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 produces a white puff of steam. This shows that the cars are ready for action. Purging the nitrous oxide also decreases the chance of a nitrous backfire.

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 orange, 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. These orange 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 bottom orange light (or sometimes all the orange 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.

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 the car is immediately disqualified (known as "red-lighting"). 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.

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.

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 four 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. Finally, 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.

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. 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.

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.

An amateur "Day at the races"

While the professional and other faster classes get all the attention on tv and in the press, there are far more casual and weekend racers for whom it's just an enjoyable hobby. Many potential first-time amateur drag racers are put off by their lack of knowledge as to what to do. Assuming a 13.0 second or slower car (most unmodified street cars other than Corvettes, Vipers, and certain Mustangs), it is relatively easy to have an enjoyable Friday night, Saturday, or Sunday afternoon (differs by track).

Getting ready

The first requirement is locating a nearby drag strip. Whether it's NHRA or IHRA is unimportant in the beginning, any track will do. Web searches, going to the NHRA/IHRA sites, asking friends, or even the yellow pages should locate one reasonably close. They will be able to tell you on the phone what dates/times they have races for street cars, and the cost to race (watching is cheaper, be sure to mention you'd like to race your vehicle). Also be sure to get the two most important times - the time they open, and the time actual racing starts (usually 2-3 hours later). The difference is so amateurs can have "practise runs" to determine what kinds of times their cars will achieve. Street classes are always bracket racing (see above). There are two reasons to try to arrive right as the track is opening. First, the "pit area", where all cars that will race initially congregate offers better spots (closer to the track) early on, and secondly, there is the opportunity to get more practise runs in.

What to bring

A helmet, motorcycle-style, preferably DOT (Department of Transportation) approved, since some stricter tracks will insist on this, and white shoe polish in an applicator-type container (discussed later). Alcoholic beverages are not allowed. Snacks and other beverages are acceptable. Some people enjoy using a digital camera to capture the action. Many amateur enthusiasts enjoy bringing friends, especially in another vehicle, to enjoy the racing with and to assist with picture-taking. Earplugs are also a wise choice, as is windex and paper towels.

When you first arrive

Depending on the track, you may need to have the car "teched", which means inspected. Gate attendants (where you enter and pay) are used to this question, and know whether a street car needs to be teched or not. Two things can happen here. First, you need to have the car teched and should go to this area. Second, there is no tech requirement for street classes (mostly IHRA tracks), and so you simply head for the pit area. In the case of a tech requirement, you will have to have an official look over the car and be sure there are things such as seat belts, a correct helmet (if required), street-legal tires, a correct exhaust, and other street-legal items. The tech official (assuming the vehicle passes) will then use his white shoe-polish (or other substance) to paint an identifying number on your upper-passenger windshield, and possibly on a side window as well. The official will then give you a slip verifying you have been teched and you may then proceed to the pit area. In the case of no tech requirements, be sure to save the stub you got at the gate, since you will be asked for it before being allowed to race.

The pit area

Unlike NASCAR, the pit area in amateur drag racing is basically a huge parking lot. If your car didn't need to be teched, you will need a number on your windshield. Although most tracks have an official who will supply the number, not all do. Use the shoe polish up high on the passenger side, then draw a line under it (explained later). The pit area is where everyone in amateur drag racing walks around and enjoys talking to other people, seeing cars that are similar, and generally just "talking trash" with others over performance. Arriving early, as mentioned, means you can get in line to do a few practise runs down the track. During these runs, it's only practise so you could conceivably be paired up with a much faster car. The object here is not to win, but to simply get a feel for how your car performs. All tracks have a place back around the pits where you can get a "timeslip" after a run.

The timeslip

Years ago, timeslips were written out by hand, but now they are computerized. A quarter mile is a fair amount of distance, and after slowing down the car will need to turn around (not on the track - there are roads leading back to the pit area). There will be a small building or other place (just ask) where you will get a slip of paper with your number at the top (and the one you raced against as well). Aside from winning or losing, practise runs are the same as the real thing. You'll get your ET (elapsed time), your speed through the traps (MPH at finish), and your reaction time. Most tracks also include your time at various intervals on the way down the track. One of the most common is known as the "60 foot" time. The 60 foot time is a good indication of how quickly you got off the line. Of course, the reaction time is very important. Drag racers who fall asleep at the line when the light turns green rarely win.

Dialing in

Before actual racing begins, drag racers will need to dial-in, or put their estimated time on their windshield underneath the ID number. The time is to the hundredth, as in "14.55". After a couple of practise runs most racers have an idea of how their vehicle is going to perform. It is worth noting that the time you put up there is an estimate of the fastest time your car will go, since going faster than your dial-in will result in disqualification. You are allowed to change this number as many times as you like, right up until you actually stage for the race. Shoe polish is easily removed with windex and a few paper towels. A common ego trip for many weekend drag racers is to paint a ridiculous dial-in (say, 8.45) on a slow car that can barely do 17s and watch as people walk by and wonder what you have under the hood.

Time to race

Missing image
These cars are running 12s. The Viper is stock, right off the showroom floor.

Eventually, the loudspeakers will begin calling various classes to line up for the race. There will likely be 3 or 4 lanes to line up in. Be sure to know what class you are running in. For example, it is unwise to drive a stock Dodge Neon into a Top Fuel lineup. As a rule, one class at a time is called. Everyone else comes to watch, take pictures, or tweak their cars until it is their turn. When your turn comes to get in line, the adrenalin starts. A track official will point to the two cars he or she wants on the line, and the racing process (see above) begins. One or two lanes are kept empty for winners to re-line up in. After the first round, the winners race again. This goes on until someone wins the class and gets either a trophy or some money. Some tracks are generous and award trophies to anyone who simply wins a single race. Other tracks require the racer to win it all before getting anything. Most fall in between.

After the race

If you wait until the very end, the pit area will likely be almost empty, since most people just leave after they lose. Many ego types will re-paint a wild time on their cars and head for the local 7-11 to brag. Others will simply go home. Either way, casual drag racing is fun and millions do it each and every weekend.

A few all-time stars of drag racing

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