Top Fuel dragsters is the fastest racing car in the world and the fastest drag racer category, with the fastest competitor reaching speeds of 335 miles per hour (539 km/h) and completing 1,000 feet (305 m) running in 3.64 seconds.
Due to its speed, this class almost exclusively ran only to a distance of 1,000 feet (300 m), and not 1,320 ft (400 m). The rules were amended in 2008 by the National Hot Rod Association after the fatal accident of driver Funny Car Scott Kalitta during a qualifying session at Old Bridge Township Raceway Park in Englishtown, New Jersey, USA. Shortening distance is used in the FIA ​​on multiple tracks, and by 2012 it is now the standard Fuel Top range by the FIA. The International Hot Rod Association, which now implements the Top Fuel in Australia, dropped the distance in September 2017 after Santo Rapisarda, the owner of a car that often runs NHRA races in the United States, pushed for the change.
A top fuel puller accelerates from rest to 100 mph (160 km/h) in just 0.8 seconds (less than a third of the time required by Porsche 911 Turbo production to reach 60 mph (100 km/h)) and can exceed 280 mph (450 km/h) in just 660 feet (200 m). This subject is the driver for an average acceleration of about 4.0 g 0 (39 m/s 2 ) for the duration of the race and with a peak of more than 5.6 < i> g 0 (55 m/s 2 ).
Video Top Fuel
Top Fuel Race
Before running, drivers often do
At maximum throttle and RPM, the exhaust gases that come out of the dragster open header produce about 900-1,100 pound-force (4.0-4.9 kN) downforce. Large airfoils above and behind the rear wheels generate more, peaking around £ 12,000 (53 kN) when the car reaches speeds of around 330 mph (530 km/h).
Top Fuel dragster engines produce about 150 dB of sound at full speed, enough to cause physical pain or even permanent damage. An intense voice is not only audible, but it is also felt as a thrill vibration throughout a person's body, which causes many people to compare the experience of watching Top Fuel dragsters making bait to 'feeling as though the whole drag strip is being bombed.' Before running, the race announcer usually advises the audience to cover or listen to their ears. Ear plugs and even earplugs are often given to fans at the entrance of the Top Fuel show.
Dragsters are limited to a maximum wheelbase of 300 inches (760 cm).
Currently, the most productive active driver in the Top Fuel is Tony Schumacher, and the most successful crew chief is Alan Johnson, who is the crew chief for six Schumacher championships, a back-to-back title won by racer Gary Scelzi and is the crew chief for his brother Blaine for his entire professional career. The first female rider in the Top Fuel category was also the most closely related drag racing woman, Shirley Muldowney, who won three championships during her career.
Maps Top Fuel
Fuel
Since 2015, NHRA regulations limit fuel composition to a maximum of 90% nitromethane; the rest is mostly methanol. However, this mixture is not mandatory, and fewer nitromethane can be used if desired.
While nitromethane has a much lower energy density (11.2 MJ/kg (1.21 Mcal th /lb)) compared to gasoline (44 MJ/kg (4.8 Mcal th /lb)) or methanol (22.7 MJ/kg (2.46Ã, Mcal th /lb)), the nitromethane burning engine can generate 2.3 times more power than gasoline which burned the machine. This is made possible by the fact that, in addition to fuel, the engine must burn oxygen to generate power: 14.7 kg (32 lb) of air (21% oxygen) is required to burn a kilo (2.2 lb) of gasoline, compared to just 1, 7 kg (3.7 pounds) of air for one kilogram of nitromethane, which, unlike gasoline, already contains oxygen in its molecular composition. For the given energy output, this means that the engine can burn 8.7 times more nitromethane than gasoline.
Nitromethane also has a high latent heat from evaporation, which means that it will absorb large engine heat as it evaporates, providing an invaluable cooling mechanism. The velocity of laminar flame and combustion temperature is higher than gasoline respectively at 0.5 m/s (1.6 ft/s) and 2,400 º C (4,350 Â ° F). The power output can be increased by using a very rich mixture of air fuel. It's also something that helps prevent pre-ignition, something that usually becomes a problem when using nitromethane.
Due to the relatively slow rate of burning of nitromethane, a very rich fuel mixture is often not completely ignited and some of the remaining nitromethane can exit the exhaust pipe and glow when in contact with atmospheric oxygen, burning with distinctive yellow flame. In addition, after sufficient fuel has been burned to consume all available oxygen, nitromethane can burn without atmospheric oxygen, producing hydrogen, which is often seen burning from the nighttime drain pipe as a bright white flame. In running the machine can usually consume between 12 gallons US (45Ã, L) and 22.75 US gallons (86.1Ã, L) of fuel during heating, exhaustion, staging, and a quarter mile run.
Top fuel engine
Rules
Like many other motor sport formulas coming from the United States, NHRA-supported drag racing supports weight restrictions on engine configuration, sometimes to the detriment of technological developments. In some cases, teams are required to use technology that may be decades old, resulting in a car that may appear to be much lower than the average family car. However, while some basic aspects of engine configuration are very limited, other technologies, such as fuel injection, clutch operation, ignition, and materials and car design, are under constant development.
The NHRA competition rules limit the movement of machinery to 500 cubic inches (8.190 cm 3 ). A 4.1875 inch (106 mm) hole with a 4.5 inch (114 mm) stroke is the usual dimension. Larger bores have been shown to weaken the cylinder block. The compression ratio is about 6.5: 1, as is common in machines with Roots-overdriven superchargers.
Engine
The engine used to drive the Fuel Top drag racing car follows the basic layout found in the second generation Chrysler 426 Hemi "Elephant Engine" made from 1964-1971. Although the Top Fuel engine is built exclusively from specialist parts, it retains the basic configuration with two valves per cylinder activated by pushrods from a centrally placed camshaft. The engine has a cleavage chamber, a 90-degree valve stem angle; Bore pitch 4.8 inches (120 mm). This configuration is identical to the overhead valve, the camshaft-in-block "Hemi" V-8 engine that became available for sale to the public at Chrysler Corporation (Chrysler brand) of certain automotive products in 1950 (1951 model).
This block is done from a piece of wrought aluminum. It has a ductile iron-press coating. There are no drains in the block, which add strength and stiffness. The engine is cooled by a mixture of air/incoming fuel and lubricating oil. Like the original Hemi, the racing cylinder block has a deep skirt for strength. There are five main bearing caps, which are tied with steel studs to standard aircraft, with main buttons and cross-bolting. There are three approved suppliers for this custom block.
The cylinder head is worked from an aluminum billet. Thus, they also lack a water jacket and rely entirely on the mixture of incoming air/fuel and lubricating oil for cooling. The original Chrysler design of two large valves per cylinder was used. The intake valves are made of solid titanium and the exhaust from Nimonic 80A is solid or similar. Chairs made of ductile iron. Beryllium copper has been tried but its use is limited due to its toxicity. The valve size is about 2.45 in (62.2 mm) for intake and 1.925 deep (48.9 mm) for the exhaust. In the port there is an integral tube for the thrust rod. Head sealed to block by copper gasket and o-ring stainless steel. Securing the head to the block is done with stud stud and stud bears assessed by the aircraft.
Camshaft is a billet steel, made of 8620 carbon or S7 through a hardened tool steel or the like. It runs on five pressure lubricating oil bearing pads and driven by gears on the front of the engine. The mechanical roller lifter (cam follower) rises above the cam lobe and pushes the steel thrust into the arm of the steel rocker that moves the valve. The rockers are a type of roller tip on the side of the intake and exhaust. Like the cam follower roll, the tip steel roll rolls on steel roller bearings and rotating steel swing arm on a pair of tool-mounted steel shafts hardened in bronze bushing. Rocker Intake and exhaust is billet. Double valve springs are coaxial and made of titanium. The valve regulator is also made of titanium, as does the rocker cover.
Steel billet crankshafts are used; they all have a cross plane configuration a.k.a. 90 degrees and run in five conventional bearing shells. 180 degree crankshafts have been tried and they can offer increased power. A 180-degree crankshaft is also about 10 kg (22 lb) lighter than 90 degrees crankshaft, but they create a lot of vibration. Such is the strength of the top fuel crankshaft that in one incident, the entire engine block is split and blown from the car during engine failure, and the crank, with all eight connecting rods and pistons, is left still shot to the clutch.
Piston made of fake aluminum. They have three rings and the aluminum key retains 1,156 in ÃÆ'-3,300 deep (29.4 mm × 83.8 mm) steel wrist pins. Pistons are anodized and Teflon coated to prevent painful during meetings of high load thrust load operations. The top ring is the L-shaped "Dykes" ring section that provides a good seal during combustion but a second ring should be used to prevent excessive oil entering the combustion chamber during the stroke intake as Dykes style rings offer less than optimal reverse sealing of gas/oil. The third ring is an oil dredging ring whose function is to scrape most of the oil film from the cylinder wall as the piston descends, to prevent oil from burning heat and contaminate the upcoming fuel/air rotation. This "oil erosion" also provides a major heat removal step for cylinder walls and piston skirts, the oil film is refurbished as the piston moves upward after the BDC.
The connecting rods are made of wrought aluminum and provide some shock attenuation, which is why aluminum is used instead of titanium, because the titanium connective rod sends too much impulse burning to the large rod bearings, endangering the bearings and thus the crankshaft and block. Each con rod has two bolts, a shell bearing for the big end while the pin goes directly on the rod.
Supercharger
Supercharger must be a Roots type 14-71. It has a twisting lobe and is propelled by a toothed belt. Supercharger slightly offset backwards to provide air distribution. The absolute manifold pressure is usually 56-66 pounds per square inch (390-460 kPa), but up to 74 pounds per square inch (510 kPa) is possible. Manifolds are equipped with exploded plates 200 pounds per square inch (1,400 kpa). Air is fed to a compressor from a throttle butterfly with a maximum area of ​​65 sq at (419 cm 2 ). At maximum pressure, it takes about 1,000 horsepower (750 kW) to drive the supercharger.
These superchargers are actually derivatives of General Motors who picked air blowers for their two-stroke diesel engine, adapted for automotive use in the early days of the sport. The model names of these superchargers illustrate their size - the commonly used 6-71 and 4-71 blowers designed for General Motors diesel engines that have six cylinders of 71 Â ° c at (1.160 cm 3 ) each , and four cylinders each 71 cm (1,160 cm). Thus, the current 14-71 design can be seen as a major improvement in power distribution over the initial design, tailored for the Detroit Gas Diesel power plant.
Security rules are required to require a safe Kevlar style blanket over the supercharger assembly as a "blower blast" not infrequently, from a volatile air/fuel mixture coming from a fuel injector drawn directly through it. The absence of a protective blanket exposes the driver, team and spectator to shrapnel at an event that is almost every irregularity in the air/fuel mixture induction, the conversion of the combustion into a rotating crankshaft movement, or in exhausting the spent gas is encountered..
Note that Detroit Diesel does not produce 14-71.
Oil and fuel system
The oil system has a wet tube containing 16 liters of US (15Ã, l) of SAE 70 mineral or synthetic racing oil. Pans made of titanium or aluminum. Titanium can be used to prevent oil spills in the event of blown stems. Oil pump pressure is about 160-170 psi (1,100-1,200 kPa) during run, 200 psi (1,400 kPa) at start up, but actual numbers differ between teams.
Fuel is injected by a constant flow injection system. There are mechanically driven fuel pumps and about 42 fuel nozzles. The pump can drain 100 gallons US (380 liters per minute at 7500 rpm and 500 psi (3,400 kpa) fuel pressure Generally 10 injectors are placed in the injector cap over the supercharger, 16 in the intake manifold and two per cylinder on the cylinder head. the race begins with a slimmer mix, then when the clutch begins to tighten as the engine speed increases, the air/fuel mixture is enriched.As the increase in engine speed increases the pump pressure, the mix is ​​made slimmer to maintain a predetermined ratio based on many factors, the friction of the surface of the racing track.The stoichiometry of both methanol and nitromethane is much larger than racing petrol, because they have oxygen atoms attached to their carbon chains and no gasoline.This means that the "fuel" engine will provide power over a very wide range of a very sleek mixture to very rich achieve maximum performance, before each race, by varying the fuel level supplied to the engine, the mechanical crew can choose the power output that is almost below the tire traction limit. The power output that makes the tire slip will be "tire smoke" and as a result races are often lost.
Ignition and timing
The air/fuel mixture is ignited by two 14 mm (0.55 inch) plugs per cylinder. This plug is fired by two 44 ampere magnets. The normal ignition timing is 58-65 degrees BTDC (This is a much larger spark advance than in gasoline engines like "nitro" and alcohol burning much more slowly). Immediately after the launch time usually decreases by about 25 degrees for a short time as this gives the tire time to reach the correct shape. The ignition system limits the engine speed to 8400 rpm. The ignition system provides 50,000 volts and an initial 1.2 amperes. Long spikes (up to 26 degrees) provide 950 millijoules of energy (0.23 calories th ). Plugs are placed in such a way that they are cooled by the incoming charge. Ignition systems are not allowed to respond to real-time information (no computer-based spark-stage alerts), so instead a time-based retard system is used.
Exhaust
The machine is equipped with eight individual open exhaust pipes, 2.75 in (69.8 mm) in diameter and 18 in (457 mm) in length. It is made of steel and is equipped with thermocouples to measure the temperature of the exhaust gases. They are called "zoomies" and the exhaust gases are directed up and back. The exhaust gas temperature is about 500 Â ° F (260 Â ° C) at idle and 1,796 Â ° F (980 Â ° C) at the end of the run. During nighttime events, slow-burning nitromethane can be seen to extend the fire a few feet from the exhaust pipe.
The engine is warmed for about 80 seconds. After heating the lid the valve is taken, the oil turns and the car is refilled. Running includes a 100-second tire heating that produces a "spin" of about three minutes. After each round, the entire engine is disassembled and checked, and worn or damaged components are replaced.
Performance
Measuring the power output of the top fuel engines directly is not always feasible. Certain models use torque sensors incorporated as part of the RacePak data system. Dynamometers that can measure the output of Top Fuel engines exist; however, the main limitation is that the Top Fuel engine can not run at its maximum power output for more than 10 seconds without overheating or possibly destroying itself explosively. Creating such high power levels from relatively limited displacements is the result of using a very high level of drive and running at a very high RPM; both emphasize internal components to a high level, meaning that peak forces can only be achieved safely for short periods of time, and even then simply deliberately sacrificing components. The engine power output can also be calculated based on the weight of the car and its performance. The calculated power output from this engine is likely to be between 8,500 and 10,000 hp (6,340 and 7,460 kW), which is about twice as powerful as those mounted on some modern diesel locomotives, with a torque output of about 7,400 pound -feet style (10,000 Ã, N? M) and effective pressure means brakes 1,160-1,450Ã, psi (8.0-10.0 MPa).
By the end of 2015, tests using sensors developed by AVL Racing show peak power of over 11,000 hp (8,200 kW).
For comparison purposes, the 2009 SSC Ultimate Aero TT, which at that time is among the world's most powerful production cars, generates 1,287 hp (960 kW) of power and 1,112 lbf? Ft (1.508 Nm) of torque.
Machine weight
- Block with 187 pounds (84.8 kg) liner
- Head 40 pounds (18.1 kg) each
- Crankshaft 81.5 pounds (37.0 kg)
- A complete 496 pound (225 kg) machine
Compulsory security equipment
Many organized drag racing are approved by the National Hot Rod Association. Since 1955, the association has held regional and national events (usually held as a single elimination tournament, with the winner of each of two advanced car races) and has set rules for safety, with stronger cars that require more safety equipment.
Typical security equipment for contemporary top fuel dragster: full face helmet with installed HANS device; multi-point, fast release fastener fastener; full body fire suits made of Nomex or similar materials, complete with face masks, gloves, socks, shoes and boots like shoes, all made of refractory material; on board fire extinguishers; kevlar or other synthetic "anti-bullet" blankets around the supercharger and the clutch assemblies contain damaged components in case of failure or explosion; fuel tanks, lines and fixtures that are resistant to damage; fuel and externally accessible ignition caps (constructed for access by rescue staff); parachute braking; and a host of other equipment, all built with very high manufacturing standards. Any breakthrough or discovery that may contribute to the driver, staff, and audience safety is likely to be adopted as a mandatory rule for competition. The 54-year history of NHRA has provided hundreds of examples of increased safety.
In 2000, NHRA mandated a maximum concentration of nitromethane in a car fuel of no more than 90%. In the wake of the death of Gateway International Raceway in 2004, involving racer Darrell Russell, the fuel ratio was reduced to 85%. The complaints from the team in terms of cost, however, have resulted in revoked rules beginning in 2008, when the fuel mix returned to 90%, as the NHRA team owner, crew chief, and supplier complained about mechanical failure that could lead to oildown or more accidents severe caused by a reduced mixture of nitromethane. They also entrust the enclosed roll cage.
NHRA also mandates that different rear tires are used to reduce failure, and that titanium "protective" is attached around the rear half of the frame-roll to prevent debris from entering the cockpit. This is also the result of a fatal accident at Gateway International Raceway. Rear tire pressure is also heavily regulated by Goodyear Tire and Rubber on behalf of NHRA, at 7Ã, psi (48 kPa), the absolute minimum pressure allowed.
Currently, the final drive ratio higher than 3.20 (3.2 rounds of engine to one rear axle rotation) is prohibited, in an attempt to limit the potential for the highest speed, thereby reducing the perceived hazard level.
Most NHRA Top Fuels win
References
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"The Top Fuel V8" (009). Race Engine Technology: 60-69. - "Running the Army Motor" (008). Racing Machine Technology: 60-69. Ã,
- Kiewicz, John. "Top Fuel by the Numbers" (February 2005). Motor Trends.
- Phillips, John. "Drag Racing: It's Like Throwing Your Toilet with Claymore Mine" (August 2002). Car and Driver.
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Szabo, Bob. "Blown Nitro Racing on a Budget" (January 2013). Szabo Publishing.
External links
- Top Fired Fuel Boats from the '60s & amp; 70s
- NHRA National Rod Association website
- WSID Website
- IHRA International Hot Rod Association Web site
- Santa Pod Raceway - home of the European Drag Racing
Source of the article : Wikipedia
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