subota, 3. studenoga 2007.

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.

Top Fuel dragster
Top Fuel dragster

Basics of drag racing

A drag race is 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 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 (e.t.), 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).

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.

[edit] Racing organization

The elapsed time from the light turning green to the car's front end passing through the "traps" at the other end ("far end") of the track determines the winner; this is the elapsed time. 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.

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 are associated with one sanctioning body or the other. The NHRA is more popular with large, ¼ 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. 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.

In 1997, the FIA began sanctioning drag racing in Europe with a fully established European Drag Racing Championship, in cooperation (and rules compliance) with NHRA. The major European drag strips include Santa Pod Raceway in Podington, England, Alastaro Circuit, Finland, Mantorp Park, Sweden, Gardermoen Raceway, Norway and the Hockenheimring in Germany.

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

  • Top Fuel Dragster (TF/D) (NHRA and IHRA). The rail dragsters, or "diggers", the fastest class--85% nitromethane fuel is used. There are also a Top Alcohol--100% methanol or ethanol is used (TA/D) and Top Gas Dragster--gasoline only, is used (TG/D).
  • Top Fuel Funny Car (TF/FC) (NHRA and IHRA) Nearly as fast as the diggers, the "floppers" (marginally) resemble actual cars. IHRA will be bringing back Top Fuel Funny Car in 2006, and Alcohol Funny Car (A/FC) is already a pro category in IHRA.
  • Pro Modified (Pro Mod) Some engine restrictions, very high power. Cars can run superchargers or nitrous oxide. Cars running blowers are limited to 8.6 L (527 cubic inches) while cars with nitrous oxide can run up to 12.1 L (740 cubic inches).
  • Pro Stock (NHRA and IHRA) Must maintain stock appearance. NHRA cars can run no more than 8.2 L (500 cubic inches) while IHRA cars can run a maximum of 13.4 L (820 cubic inches) ("Mountain Motors").
  • Pro Stock Bike (NHRA only) Heavily modified motorcycles.

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's chosen "dial-in" 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 starting lights on the "Christmas tree" (commonly just "tree") 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 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 driver able to precisely predict 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 skill. Therefore, bracket racing 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.

Besides NHRA and IHRA, there are niche organizations for muscle cars and nostalgia vehicles. The National Electric Drag Racing Association (NEDRA) races electric vehicles against high performance gasoline-powered vehicles such as Dodge Vipers or classic muscle cars in ¼ and 1/8 mile races. The current electric drag racing record is 8.801s for a quarter mile.

[edit] Drag racing performance facts

The fastest top fuelers can attain terminal speeds of over 530 km/h (330 mph) while covering the quarter mile (402 m) distance in roughly 4.45 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 hydrogen peroxide rocket dragsters such as Sammy Miller and Kitty O'Neil's 3.22 ET and 663 km/h (412 mph) quarter mile world records set in 1977). In fact, a vehicle traveling at a steady 200 mph (322 km/h) as it crosses the starting line will be beaten to the finish line by a top fuel dragster starting from a dead stop at the same moment. Additionally, through the use of large multiple braking parachutes, the astounding performance of 0 to 531 km/h (0 to 330 mph) and then back to 0 in 20 seconds can be obtained. Using twin drag parachutes, deceleration of up to 5 G can be attained, enough to cause detached retinae[1]. The legendary Don Garlits, holder of multiple records (first 200 mph run, first 270 mph run...) had to retire because of a detached retina.

The faster categories of drag racing are an impressive spectacle, with engines of over 5 MW (6700 horsepower) and noise outputs to match (measured at 3.9 on the Richter Scale by seismologist Dr. Doug Brittsan), 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 car's driving wheels to spin while stationary or moving forward slowly, thus heating up the tires to proper working temperature 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 launch.

The Blown Alcohol and Nitrous Oxide injected Pro Modifieds with their 1500 kW (2012 hp) motors are capable of running in the low six second range at over 370 km/h (230 mph). The IHRA Pro Stocks are just behind, running in the 6.3 second range at over 346 km/h (215 mph), while the NHRA Pro Stocks run in the high sixes at over 322 km/h (200 mph). Top Sportsman and Top Dragster, the two fastest sportsman classes, run a bracket style race and can range from high sevens at over 274 km/h (170 mph) to 6.4s at 210 mph (340 km/h). Super Comp/Quick Rod are either dragsters or doorslammers, but run with a throttle stop. Some cars can run as low as a 7.50 at around 180 mph (290 km/h) without a throttle stop, but use it in order to hit an 8.900 index. Super Gas/Super Rod and Super Street/Hot Rod run with a 9.900 and 10.900 index respectfully, but both run with a throttle stop.

Another class of car is the Sport Compact class. Compacts use their power to weight ratio to get performance. The FIAT Topolino was the first to be exploited this way, in the notorious AA/FA, or Fuel Altered, followed by the more conventional modified VW Beetle. A turbocharger or supercharger is very common, and often necessary to break the 12-second barrier. Cars have progressed rapidly though and can now even run 7 second quarter miles.

In 2001, the NHRA bought out NIRA and renamed it the Sport Compact category featuring such cars, and while Toyota, Honda, Nissan, and Subaru are very popular, the NHRA has also permitted General Motors, Ford, and DaimlerChrysler cars to participate in Sport Compact.

With NHRA rule changes in recent years making Pro Stock cars more compact, a change from an 8.2 L (500 cubic inch) V-8 engine to a modified factory four or six cylinder double overhead camshaft engine can easily convert a Pro Stock car to Sport Compact Pro Rear Wheel Drive car. The cars are separated by performance, and since 2003 categories have been split based on the car's drive wheels. Ironically, almost all NHRA Sport Compact records for elapsed time and speed are held by General Motors and Ford cars, rather than the imports.

[edit] 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 turbochargers, superchargers, and nitrous oxide (N2O), specialized fuels (higher octane gas, methanol, etc...), improved suspensions, and a multitude of others.

[edit] The burnout

Example of a burn-out before staging at Hockenheimring, Germany. Note the amount of smoke.
Example of a burn-out before staging at Hockenheimring, Germany. Note the amount of smoke.

When approaching the starting line (also known as the staging area), most racers will apply water (formerly bleach) to the driven tires either by backing into a small puddle (the "water box") or having it sprayed on. The car then exits the water and does a burnout to heat the tires, making them even stickier. Some cars have a mandatory "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 burnout. 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.

[edit] Staging

After the burn-out comes the "staging phase", where the cars pull up to the starting line. Each lane has its own string of lights on the "Christmas tree", with two small orange lights on top. These are 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 starting line. When both cars have lit both bulbs, the starter will engage the Christmas tree. If the racer moves too far the top bulb will go out and the driver is said to have "deep staged". While some drivers prefer this technique, some tracks and classes prohibit it. An advantage can be had, by deepstaging, in gaining a quicker reaction time (RT) but at the expense of the elapsed time (ET) and MPH achieved at the top end of the track; there is also a higher risk of "red lighting" (the act of crossing the light beam before the green light has been lit)

[edit] The tree

Once the competitors have both staged, the starter presses a button to start the race. There are two types of tree used. A sportsman tree, used for bracket and handicap racing, consists of each yellow lighting 0.5 seconds after the one above it. The green comes on 0.5 seconds after the last yellow is lit. If the race is a handicap race each side of the tree will have its own timing. A pro tree consists of all three yellows being illuminated at the same time, followed by the green 0.4 seconds later. This type of tree is used for professional and heads-up racing. It should be noted that some tracks run a Pro-style tree for bracket racing during special "Street Racing" bracket events.

[edit] 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. 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 to judge shift points. In Fuel classes especially, "pedalling" the car (adjusting the throttle) to prevent loss of traction is often important and one measure of how good a driver is.

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 prevent a breakout. Especially in bracket racing, it is not uncommon to see the leading vehicle's brake lights come on briefly before the finish line. The term "sandbagging" is used in races where the driver in a bracket race puts a slower "dial in" (the predicted E.T.) that he/she could run and then at the finish line tap the brakes lightly or lift of the gas pedal to reduce the E.T. to run as close as possible to the dial in.

If both cars break out, 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 permissible time is ejected from the entire race. This is faster than the official break out elapsed time.

[edit] Glossary

  • Beam—starting line electric eye controlling "pre-staged" and "staged" lights
  • Blow—supercharge; wreck. Said of an engine.
  • Blower—supercharger (occasionally turbocharger); in '90s, generally grouped as "power adder" with turbocharger and nitrous
  • Blown—supercharged; wrecked. Said of an engine.
  • Blowover—flipping of a car, due to air under car lifting front wheels. Commonly suffered by dragsters
  • Breakout—running quicker than dial-in; also "breaking out". Grounds for disqualification if opponent does not commit a foul start or cross boundary lines.
  • Christmas Tree (or tree) —the Chrondek timing lights
  • Dial-in—when bracket racing, drivers must estimate or 'dial in' the time in which they expect to run. Therefore two unmatched cars in weight and power can compete, by a handicap system. If one runs a faster time than dialed in, it is a breakout.
  • Digger—dragster (as distinct from a bodied car or flopper)
  • Doorslammer—Pro Stock, Pro Mod, or other car with doors, from the requirement to have working doors.
  • Flopper—Funny Car, short for "fender flopper." Coined by dragster crews in the late 1960s to separate Funny Cars, which had fiberglass bodies with fenders, from dragsters. Erroneously attributed to flip-top bodies of Funny Cars.
  • Fuel—mix of methanol and nitromethane ("pop", nitro); race class using it
  • Fueler—any car running fuel or in Fuel class (most often, TFD or TF/FC)
  • Holeshot—getting a significant advantage off the starting line. The other driver gets "holeshotted" or "left at the tree". A "holeshot win" is any win in a heads-up class where a slower car beats a faster car because of better reaction time.
  • Hook Up—Good traction between tires and track resulting in increased acceleration and reduced slipping or smoking of tires.
  • Grenade—wreck an engine (the engine "grenaded") due to internal failure. Distinct from "popping a blower".
  • Lit the tires—lost traction, causing smoke
  • Nitro—nitromethane (sometimes incorrectly used to refer to nitrous oxide)
  • Overdrive-The ratio between the revolutions of the supercharger to the revolutions of the engine, controlling amount of boost; see underdrive
  • Oil Down-When a car's engine or lubrication breaks during a run, leaving a streak of oil and other fluids on the track. This is punishable by fines, point penalties, and / or suspension.
  • Pedalling—working the throttle to avoid lighting the tires; "pedalled" it, had to "pedal" it
  • Pro tree—timing lights which flash all three yellow lights simultaneously, and after four tenths of a second, turn green.
  • Put on the trailer—lost (got "put on the trailer") or won (put the other driver on the trailer). From the obvious, losing drivers trailer their cars home.
  • Quick 8 (Q8) Quickest eight cars in a defined race. Rules appear to can differ per location/race. Search for "Quick 8 rules" for more.
  • Rail—dragster (as distinct from bodied car or flopper). From the exposed frame rails of early cars.
  • Redlight(ed) a.k.a. bulb(ed)—jump(ed) the start, left before tree turned green. This is a loss unless a more serious (opponent crossing the center boundary line) foul occurs.
  • Slapper bar-traction bar
  • Slicks—rear tires with no tread pattern and softer rubber compound, for increased traction
  • Slingshot—early front-engined dragster, named for the driving position behind the rear wheels (erroneously attributed to launch speed)
  • Standard tree—timing lights which flash in sequence five tenths of a second between each yellow light before turning green. Traditional form, before introduction of Pro tree.
  • Throw a belt-losing the drive belt connecting the engine's crankshaft to the supercharger
  • Top end—finish line of strip; high part of engine's rev band.
  • Traction bars—rear struts fixed to rear axle to keep rear axle from twisting, causing wheel hop and loss of traction; also called slapper bars.
  • Trap(s)—the 20 meter (66 ft) timing lights at top end of race track to measure speed & E.T.
  • Tire shake-violent shaking of the car as the tires lose and regain traction in quick succession.
  • Wheelie bars—rear struts fixed to rear axle, which protrude out to rear of car to help prevent car's front from rasing too high or flipping over on launch.

[edit] References

  1. ^ The History of Fuel Dragsters

[edit]

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