Top Fuel
Top Fuel is a type of drag racing whose dragsters are the quickest accelerating racing cars in the world and the fastest sanctioned category of drag racing, with the fastest competitors reaching speeds of 338 miles per hour (544.0 km/h) and finishing the 1,000 foot (304.8 m) runs in 3.62 seconds.
A top fuel dragster accelerates from a standstill to 100 mph (160.9 km/h) in as little as 0.8 seconds (less than one third the time required by a production
Because of the speeds, this class races a 1,000 foot (304.8 m) distance, not the traditional drag-race length of one-fourth of a statute mile, or 1,320 feet (402.3 m). The rule was introduced in 2008 by the
Top Fuel racing
Before their run, racers often perform a burnout to clean and heat tires. The burnout also applies a layer of fresh rubber to the track surface, improving traction during launch.
At maximum throttle and RPM, the exhaust gases escaping from a dragster's open headers produce about 900–1,100 pounds-force (4.0–4.9 kN) of downforce. The massive airfoil over and behind the rear wheels produces much more, peaking at around 12,000 pounds-force (53.4 kN) when the car reaches about 330 mph (531.1 km/h).
The engine of a Top Fuel dragster generates around 150 dB[2] of sound at full throttle, enough to cause physical pain or even permanent damage. Before a run, race announcers usually advise spectators to cover or plug their ears. Ear plugs and even earmuffs are often handed out to fans at the entrance of a Top Fuel event.
Dragsters are limited to a wheelbase of 300 inches (7.6 m).
The most prolific active driver in Top Fuel is Tony Schumacher and the most successful crew chief is Alan Johnson, who was the crew chief for six of Schumacher's championships, the back-to-back titles won by driver Gary Scelzi and was the crew chief for his brother Blaine for his entire professional career.[citation needed] The first female driver in the Top Fuel category is also the most associated female in the drag racing world, Shirley Muldowney, who won three championships during her career.[citation needed]
Fuel
Since 2015,
Nitromethane also has a high latent
Due to the relatively slow burn rate of nitromethane, very rich fuel mixtures are often not fully ignited and some remaining nitromethane can escape from the exhaust pipe and ignite on contact with atmospheric oxygen, burning with a characteristic yellow flame. Additionally, after sufficient fuel has been combusted to consume all available oxygen, nitromethane can combust in the absence of atmospheric oxygen, producing hydrogen, which can often be seen burning from the exhaust pipes at night as a bright white flame. In a typical run the engine can consume between 12 US gallons (45.42 L) and 22.75 US gallons (86.12 L) of fuel during warmup, burnout, staging, and the quarter-mile run.[3][4][5]
Top fuel engines
Rules
Like many other motor sport formulas originating in the United States,
NHRA competition rules limit the
Engine
The engine used to power a Top Fuel drag racing car is based on a second generation Chrysler RB Hemi, but is built exclusively of specialized parts. It retains the basic configuration with two valves per cylinder activated by
The
The
The camshaft is billet steel, made from 8620 carbon or S7 through-hardened tool steel or similar. It runs in five oil pressure lubricated bearing shells and is driven by gears in the front of the engine. Mechanical roller lifters (cam followers) ride atop the cam lobes and drive the steel push rods up into the steel rocker arms that actuate the valves. The rockers are of roller tip type on the intake and exhaust sides. Like the cam follower rollers, the steel tip roller rotates on a steel roller bearing and the steel rocker arms rotate on a pair of through-hardened tool steel shafts within bronze bushings. Intake and exhaust rockers are billet. The dual valve springs are of coaxial type and made out of titanium. Valve retainers are also made of titanium, as are the rocker covers.
Billet steel crankshafts are used; they all have a cross plane a.k.a. 90 degree configuration and run in five conventional bearing shells. 180 degree crankshafts have been tried. Due to ease of laying out an exhaust system with even pulsation, the 180 degree crankshaft can offer increased power in engines with interacting exhaust. However this does not concern Top Fuel engines with separate exhaust pipes for each cylinder. A 180 degree crankshaft is about 10 kg (22 lb) lighter than 90 degree crankshaft, but they create a lot of vibration. Such is the strength of a top fuel crankshaft that in one incident, the entire engine block was split open and blown off the car during an engine failure, and the crank, with all eight connecting rods and pistons, was left still bolted to the clutch.
during the high thrust load operation encountered. The top ring is an L-shaped section "Dykes" ring that provides the best seal during combustion, but a second ring must be used to prevent excessive oil from entering the combustion chamber during intake strokes, as the Dykes-style ring offers less than optimal reverse gas/oil sealing. The third ring is an oil scraper ring whose function is to scrape the majority of the oil film off the cylinder wall as the piston descends from top dead center (TDC), to prevent oil being exposed to combustion heat and contaminating the upcoming round of fuel/air. This "oil scraping" also provides a key heat removal step for the cylinder walls and piston skirts, the oil film is renewed as the piston moves upward after reaching bottom dead center (BDC).The connecting rods are of forged aluminum and do provide some shock damping, which is why aluminum is used in place of titanium, because titanium connecting rods transmit too much of the combustion impulse to the big-end rod bearings,[citation needed] endangering the bearings and thus the crankshaft and block. Each con rod has two bolts, shell bearings for the big end while the pin runs directly in the rod.[citation needed]
Superchargers
The
These superchargers are in fact derivatives of General Motors scavenging-air blowers for their two-stroke diesel engines, which were adapted for automotive use in the early days of the sport. The model name of these superchargers delineates their size – the once commonly used 6-71 and 4-71 blowers were designed for General Motors diesels having six cylinders of 71 cu in (1.16 L) each, and four cylinders of 71 cu in (1.16 L) each, respectively. Thus, the currently used 14-71 design can be seen to be a huge increase in power delivery over the early designs, purpose-built for the GM Detroit Diesel truck powerplants.
Mandatory safety rules require a secured Kevlar-style blanket over the supercharger assembly as "blower explosions" are not uncommon, from the volatile air/fuel mixture coming from the
Oil and fuel systems
The oil system has a wet sump which contains 16 US quarts (15.1 L) of SAE 70 mineral or synthetic racing oil. The pan is made of titanium or aluminum. Titanium can be used to prevent oil spills in the event of a blown rod. Teams are fined and points are lost if oil is spilled on the track surface, so all teams make provision for absorbent blankets/diapers below the engine. Oil pump pressure is somewhere around 160–170 psi (1,100–1,170 kPa) during the run, 200 psi (1,380 kPa) at start up, but actual figures differ between teams.
Fuel is injected by a constant flow injection system. There is an engine driven mechanical fuel pump and about 42 fuel nozzles. The pump can flow 100 US gallons (380 L) per minute at 7500 rpm and 500 psi (3,450 kPa) fuel pressure. In general 10 injectors are placed in the injector hat above the supercharger, 16 in the intake manifold and two per cylinder in the cylinder head. Usually a race is started with a leaner mixture, then as the clutch begins to tighten as the engine speed builds, the air/fuel mixture is enriched. As the increased engine speed builds up pump pressure, the mixture is made leaner to maintain a predetermined ratio that is based on many factors, especially race track surface friction. The stoichiometry of both methanol and nitromethane is considerably greater than that of racing gasoline, as they have oxygen atoms attached to their carbon chains and gasoline does not. This means that a "fueler" engine will provide power over a very broad range from very lean to very rich mixtures. Thus, to attain maximum performance, before each race, by varying the level of fuel supplied to the engine, the mechanical crew may select power outputs barely below the limits of tire traction. Power outputs which create tire slippage will "smoke the tires" and as a result the race is often lost.
Ignition and timing
The air/fuel mixture is ignited by two 14 mm (0.55 in)
Exhaust
The engine is fitted with eight individual open exhaust pipes, 2.75 in (69.85 mm) in diameter and 18 in (457.20 mm) long. These are made of
The engine is warmed up for about 80 seconds. After the warm up the
Performance
Measuring the power output of a top fuel engine directly is not always feasible. Certain models use a torque sensor incorporated as part of the RacePak data system. Dynamometers that can measure the output of a Top Fuel engine exist; however, the main limitation is that a Top Fuel engine cannot be run at its maximum power output for more than 10 seconds without overheating or possibly destroying itself explosively. Making such high power levels from such relatively limited displacement is a result of using very high boost levels and running at extremely high RPMs; both of these stress the internal components to a high degree, meaning that the peak power can only safely be achieved for brief periods of time, and even then only by intentionally sacrificing components. The engine power output can also be calculated based upon the car's weight and its performance. The calculated power output of these engines is most likely somewhere between 8,500 and 10,000 hp (6,340 and 7,460 kW),[7] which is about twice as powerful as the engines installed on some modern diesel locomotives, with a torque output of approximately 7,400 pound force-feet (10,030 N⋅m)[8] and a brake mean effective pressure of 1,160–1,450 psi (8–10 MPa).
In late 2015, tests using sensors developed by AVL Racing showed peak power of over 11,000 hp (8,200 kW).[9]
For the purposes of comparison, a 2009
From start to finish the engine will turn 240 revolutions. Including start up, burnout, staging and the race, the engine must survive just 500 revolutions before being rebuilt.[citation needed] This calculation assumes an average racing engine speed of roughly 3,800 revolutions per minute over a period of 3.8 seconds.
Engine weight
- Block with liners 187 lb (84.8 kg)
- Heads 40 lb (18.1 kg) each
- Crankshaft 81.5 lb (37.0 kg)
- Complete engine 496 lb (225 kg)
Mandatory safety equipment
Much of organized drag-racing is sanctioned by the National Hot Rod Association. Since 1955, the association has held regional and national events (typically organized as single elimination tournaments, with the winner of each two car race advancing) and has set rules for safety, with the more powerful cars requiring ever more safety equipment.
Typical safety equipment for contemporary top fuel dragsters: full face helmets with fitted
In 2000, the NHRA mandated the maximum concentration of nitromethane in a car's fuel be no more than 90%. In the wake of a
The NHRA also mandated that different rear tires be used to reduce failure, and that a titanium "shield" be attached around the back-half of the roll-cage to prevent any debris from entering the cockpit. This also was the result of the fatal crash at Gateway International Raceway. The rear tire pressure is also heavily regulated by
At present, final drive ratios higher than 3.20 (3.2 engine rotations to one rear axle rotation) are prohibited, in an effort to limit top speed potential, thus reducing the level of danger.
History
In 1958, NHRA banned nitro in all categories; the American Hot Rod Association (AHRA) still allowed it, and Fuel Dragsters (FD), Hot Roadsters (HR), and Fuel Coupés (FC): this led to Fuel Altereds (AA/FAs), Factory Experimentals (A/FXs), and (ultimately) Funny Cars (TF/FCs).[11]
Independent drag strips, not NHRA sanctioned, offered venues for the fuel racers.[12] Smokers Car Club hosted the first U.S. Fuel and Gas Championship at Famoso Raceway in March 1959.[13] Bob Hansen won Top Fuel Eliminator (TFE) in his A/HR, with a speed of 136 mph (218.9 km/h).[14]
Jimmy Nix, who previously ran a Top Gas dragster; Jim Johnson, who ran a Dodge Polara stocker, and who had won the B/SA title in 1963; Jim Nelson; and Dode Martin pioneered TF/FC.[15] (Nix tried to persuade Chrisman to get Mercury Racing Director Fran Hernandez to allow him to run his Comet's 427 on nitro, as a way to gain leverage on NHRA, so Nix could use nitro himself).[16] These cars ran in NHRA's S/FX class, variously defined as "Super Factory Experimental" or "Supercharged Factory Experimental".[17]
They were shortly turning in E.T.s in the low 11s and trap speeds of over 140 mph (225.3 km/h); at Long Beach on 21 March, an 11.49 pass at 141.66 mph (228.0 km/h) was recorded.[18]
Bob Sullivan's Pandemonium (a '65 Plymouth Barracuda) joined about six other nitro-fuelled early funny cars facing fuel dragsters in the 1965 season.[19]
In 1971, Don Garlits introduced the Swamp Rat XIV, a rear-engined Top Fuel dragster. While others had been developed in the previous decade, it was the first successful one, winning the 1971 NHRA Winternationals.[20][21]
In 1984, Top Fuel was at a low point. It was having trouble attracting full sixteen-car fields, leading to cutting back to eight-car rosters, while the International Hot Rod Association dropped Top Fuel entirely.[22] The same year, Joe Hrudka offered a major purse, the Cragar-Weld Top Fuel Classic and "Big Daddy" Don Garlits returned to Top Fuel full-time.[23] By 1987, NHRA Top Fuel Funny Car was drawing twice as many entrants as positions available.[24]
In 2012 enclosed cockpits were allowed to be used regularly used in top fuel by the NHRA.[25]
Most NHRA Top Fuel wins
Driver | Wins |
---|---|
Tony Schumacher | 87 |
Larry Dixon | 62 |
Antron Brown | 59 |
Steve Torrence | 54 |
Doug Kalitta | 54 |
Joe Amato | 52 |
Kenny Bernstein | 39 |
Don Garlits | 35 |
Cory McClenathan | 34 |
Gary Scelzi | 29 |
Gary Beck | 19 |
Darrell Gwynn | 18 |
Brandon Bernstein | 18 |
Spencer Massey | 18 |
Shirley Muldowney | 18 |
Scott Kalitta | 17 |
Shawn Langdon | 17 |
Brittany Force | 16 |
Dick Lahaie | 15 |
Gary Ormsby | 14 |
Don Prudhomme | 14 |
Eddie Hill | 13 |
Justin Ashley | 13 |
Mike Dunn | 12 |
Morgan Lucas | 12 |
Leah Pruett | 12 |
Doug Herbert | 10 |
Connie Kalitta | 10 |
Richie Crampton | 10 |
J.R. Todd | 9 |
Mike Salinas | 9 |
Del Worsham | 8 |
Billy Torrence | 8 |
Rod Fuller | 7 |
Darrell Russell | 6 |
Clay Millican | 6 |
Pat Austin | 5 |
Austin Prock | 4 |
Blaine Johnson | 4 |
Khalid alBalooshi | 4 |
David Grubnic | 4 |
Melanie Troxel | 4 |
Lori Johns | 4 |
Shelly Anderson Payne | 4 |
Gene Snow | 3 |
Bob Vandergriff Jr. | 3 |
Jim Head | 3 |
Pat Dakin | 2 |
Tommy Johnson Jr | 2 |
Frank Hawley | 2 |
Terry McMillen | 2 |
Blake Alexander | 2 |
Josh Hart | 2 |
Mark Oswald | 2 |
Tripp Tatum | 1 |
Hillary Will | 1 |
Cristen Powell | 1 |
Lucille Lee | 1 |
Ron Capps | 1 |
Tom McEwen | 1 |
Ed McCulloch | 1 |
See also
References
- ^ Clarke, John. "Just how fast is a Top Fuel drag car?". NobbyVille.com. John Clarke. Retrieved 8 November 2015.
- ^ "The Mag: Drag racing, the loudest sport". ESPN.com. 2010-11-05. Retrieved 2016-07-24.
- ^ "NHRA 101". NHRA.com. National Hot Rod Association. Retrieved 21 March 2017.
- ^ Smith, Jeff; Asher, Jon (1 September 2010). "8,000HP Top Fuel Engine". Hot Rod Network. Hot Rod Network. TEN: The Enthusiast Network. Retrieved 7 September 2015.
- ^ "Top Fuel by the Numbers". MotorTrend Magazine. TEN: The Enthusiast Network. February 2005. Retrieved 7 September 2015.
- ^ Jodauga, John. "Top 10 Top Fuel Innovations" (PDF). Archived from the original (PDF) on 6 September 2015. Retrieved 5 September 2015.
- ^ "FORGET 8,000 HORSEPOWER ... TOP FUEL IS NOW OVER 10,000 HORSEPOWER!". TMC News. Retrieved 24 June 2015.
- ^ "FORGET 8,000 HORSEPOWER ... TOP FUEL IS NOW OVER 10,000 HORSEPOWER! [National Dragster]". www.nfvzone.com. Retrieved 2016-07-24.
- ^ Magda, Mike (8 December 2015). "Test Shows Top Fuel Nitro Engine Makes Over 11,000 Horsepower". Engine Labs. Retrieved 2 May 2016.
- ^ NHRA News: Nitro percentage to be raised to 90 in Top Fuel, Funny Car in 2008 (9/15/2007)[permanent dead link]
- ^ McClurg, Bob. Diggers, Funnies, Gassers and Altereds: Drag Racing's Golden Age. (CarTech Inc, 2013), p.46.
- ^ McClurg, Diggers, p.46.
- ^ McClurg, Diggers, p.46.
- ^ McClurg, Diggers, p. 46. McClurg does not mention his e.t.
- ^ McClurg, Bob. "50 Years of Funny Cars: Part 2" in Drag Racer, November 2016, p.35; Burgess, Phil National Dragster Editor. "Early Funny Car History 101", written 22 January 2016, at NHRA.com (retrieved 23 May 2017)
- ^ Burgess, Phil National Dragster Editor. "Early Funny Car History 101", written 22 January 2016, at NHRA.com (retrieved 23 May 2017)
- ^ Burgess, Phil National Dragster Editor. "Early Funny Car History 101", written 22 January 2016, at NHRA.com (retrieved 23 May 2017)
- ^ Wallace, Dave. "50 Years of Funny Cars" in Drag Racer, November 2016, p.22 and caption.
- ^ Wallace, p.30 caption.
- ^ Hot Rod. Dec 1986. p. 28.
{{cite magazine}}
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(help) - ^ Front to back: The rear-engine transition (Part 1, Part 2) - Phil Burgess, NHRA, February 2015
- ^ Ganahl, Pat. "Winter Heat: '87 NHRA Wnternationals", in Hot Rod, May 1987, p.88.
- ^ Ganahl, Pat. "Winter Heat: '87 NHRA Wnternationals", in Hot Rod, May 1987, p.88.
- ^ Ganahl, Pat. "Winter Heat: '87 NHRA Wnternationals", in Hot Rod, May 1987, p.88.
- ^ "NHRA approves enclosed cockpit for Top Fuel dragster use". sports.yahoo.com. Retrieved 2023-01-05.
- "The Top Fuel V8" (9). Race Engine Technology: 60–69.
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(help) - "Running the Army Motor" (8). Race Engine Technology: 60–69.
{{cite journal}}
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(help) - Kiewicz, John. "Top Fuel by the Numbers". Motor Trend. No. February 2005.
- Phillips, John. "Drag Racing: It's Like Plunging Your Toilet with a Claymore Mine". Car and Driver. No. August 2002.
- Szabo, Bob. "Blown Nitro Racing on a Budget" (January 2013). Szabo Publishing.
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External links
- Restored Top Fuel Dragsters from the 60s & 70s
- NHRA National Hot Rod Association Website
- WSID Website Archived 2013-07-23 at the Wayback Machine
- IHRA International Hot Rod Association Website
- Santa Pod Raceway - the home of European Drag Racing