The Amazing Engineering of Top Fuel Dragsters

top fuel dragsters are the fastest accelerating ground vehicles in the world and have power outputs of up to 12 000 horsepower but how do they do that and still stay in one piece and how do they put that amount of power down onto the ground without destroying the tyres in an instant this is the amazing engineering behind the top fuel dragsters this video is sponsored by brilliant if you ever wonder why top fuel is so called it's because of what's used to power these engines a mix of 90 nitro methane and 10 methanol and that's what gives these vehicles their huge amount of power the acceleration they achieve at launch is in the order of five g's for the driver and after just naught point eight seconds and at sixty feet or eighteen meters they're already doing a hundred miles an hour with two hundred miles an hour coming up at around two point two seconds or 350 feet or 106 meters the so far fastest 1 000 foot run was set by britney force in a 2019 car quest top fuel dragster when she ran a 3.659 second run at 338.17 miles an hour but all that power comes at a very high cost with the engines needing to be completely stripped down and rebuilt after every race and that's if you're lucky and it hasn't exploded going down the track and that's what gives top fuel its attraction it's not only the fastest loudest motor sport on earth you're never quite sure if the cars will even make it past burnout in a world where we think of production vehicles with engine outputs of up to 1500 horsepower like the bugatti chiron as being reliable and with correct servicing capable of tens of thousands of miles or more it's easy to forget that when you're really pushing the limits of the internal combustion engine things become a lot trickier but it's amazing to see what's possible with a basic engine design that dates back to the 1950s the fuel used is nitro methane which is widely used in industry as a reaction medium and solvent this is what's called a monofuel meaning that it carries its own oxygen with it unlike gasoline which needs to be mixed with air to combust but nitro has a much lower energy density than gasoline at 11.2 megajoules per kilogram to gasoline's 44 megajoules per kilogram however gasoline needs 14.7 kilograms of air with a 21 oxygen content to burn one kilogram of gasoline nitro on the other hand because it carries its own oxygen needs only 1.7 kilograms of air to burn one kilo of nitro the upshot of this is that you can get 8.6 times more nitro into the combustion chamber than gasoline and in general a supercharged top fuel engine makes about eight times more power than the equivalent supercharged gasoline-powered engine now you would think that to handle all that power you would need some super high-tech engine like they're having formula one cars but actually all top fuel engines are based on a chrysler v8 hemi engine design dating back to the early 1950s their size is limited to 500 cubic inch or 8.2 liters and they have a push rod operated two valve cross flow head driven from a single centrally mounted camshaft a far cry from modern five valve double overhead cam engines or even computer-controlled pneumatic valves in the latest race engines this engine architecture and the type of supercharger use is part of the nhra rules which might look arcane in this day and age but it keeps with the tradition of the sport it also keeps a more level playing field and the cost down with the typical complete top fuel engine including fueling and supercharger running at about a hundred thousand dollars and it sounds rather expensive but compared to the seven to ten million for an f1 engine it's a bargain by comparison whilst the engine format might be the same as the old hemis what they're made out of is very different the engine block is machined from a solid piece of aluminium as are the cylinder heads but there are no water cooling jackets in these engines the fuel itself provides for cooling for the valves and the pistons and don't forget they only run at full power for less than five seconds on a run the crankshaft is billet steel and the connecting rods are forged aluminium and not titanium because aluminium has greater shock absorbing qualities and lessens the combustion shock on the upper big end bearings crankshaft and the block itself these aluminium rods dwarf for steel rods of the normal engine the cylinder pressures in a top fuel engine can be over 13 000 psi and this compressive load physically shortens the rod length over several runs and decreases the compression ratio thus reducing the power output the life of the connecting rods is around about 10 to 12 runs or less but the bearings have changed after every run one of the main tuning devices in the engine is actually the copper head gasket depending upon the weather and track conditions a couple of hours before the race the crew will decide what thickness of copper head gasket they will use as this will affect the compression ratio and thus how much power the engine will make which is why the car arrives at the track with the heads off at launch the engine revs to about 8 500 rpm but once the car is traveling down the track this is limited to 7900 rpm and this is done to try and limit the top speed to about 330 miles an hour a couple of the main reasons why this is done is partly to keep the tyres in one piece but also for insurance purposes as insurance companies get rather panicky at speeds above this because most of the fatal crashes of the past have involved these very high speeds to take the extreme heat the exhaust valves are made from inconel the same super alloy used in the thrust chamber for rocketdyne f1 engines for the saturn v rockets the spark plugs on the other hand face a much shorter life with most of the electrodes being burned off during the run the twin msd 44 amp magnetos produce a 60 000 volt 1.2 amp spark to each of the twin sparks per cylinder but even that is not always enough to ensure combustion takes place the nitro fuel is pumped in via 34 injectors 16 in the heads 8 in the intake manifold and 10 in the blower hat at 500 psi from a 17 gallon fuel tank at the front of the vehicle via a two and a half inch or 63 millimeter pipe to the 100 gallon or 378 liter per minute rated fuel pump even the fuel tank has a vent pipe right at the front of the chassis where at high speed it has a ram air effect and helps pressurize the fuel before it enters the fuel pump in a typical run of under 4 seconds the engine will use about 20 gallons of nitro that's 5.5 gallons or 20 liters per second a 50 gallon or 190 liter drum of nitro costs about a thousand dollars all of this is then forced into the engine at a pressure of 65 psi by the 1471 root type supercharger these were originally developed for diesel truck engines but they are now the mandated supercharger type for top fuel the twisted load design requires about horsepower to drive them at full speed and via a very large kevlar toothed belt from the crank and they also have to be covered with a kevlar blanket to protect against shrapnel as blower explosions are not uncommon if there is a dropped valve and a backfire into the supercharger the charge in the combustion change is actually so dense that these engines run a very fine line between hydraulicing the cylinder on liquid fuel and the combustion of gas the exhaust from each cylinder then exits via open headers which are pointed up and backwards in fact the force of the exhaust exiting upwards adds about another thousand pounds or 4.5 kilonewtons of downforce and a bit of extra forward thrust too each of the headers has a thermocouple that records the temperature of the exhaust gas and can tell how lean or rich the engine is running because nitro is a slow burning fuel compared to gasoline some of it is still unburned it leaves the exhaust and due to its high temperature it reignites as it mixes with the atmospheric oxygen creating the huge rooster tails of yellow flames you see from the exhaust some top fuel engines run a very rich mixture to help cool the valves and pistons and lessen the detonation as this very rich air nitro mix combusts it breaks down into hydrogen and carbon monoxide which leaves by the exhaust this can be seen at night as the very bright white flame as the hydrogen burns off as it mixes with the atmospheric oxygen in the air the exhaust from a top fuel is also the loudest of any motor sport at about 160 decibels although the stated power of the most powerful fuel is around 11 or even 12 000 horsepower the actual outputs are not measured directly on a dyno but calculated from the run time weight of a vehicle and the track conditions on the run there are dinos out there that can handle this type of power but fueler engines can't run at full power for more than 10 seconds without overheating or destroying themselves making it a rather expensive exercise the amount of power the crew think is required to make the best run is dialed in on the start line just before each run and as such they can vary depending upon the conditions some of the fuel cars have torque sensors which have recorded peak torque figures of over twelve thousand feet pounds of torque or sixteen thousand two hundred newton meters roughly ten times that of a bugatti chiron getting that power to the ground is done by a multiple plate clutch in a titanium housing which is connected directly to the rear axle there is no gearbox here the engine is connected directly to the final drive through the clutch which slips in a timed manner from the launch up until about 280 miles an hour where it locks up and feeds the full power to the wheels and after each run the clutch plates are replaced the live rear axle uses a 12 and a quarter inch gear set with a 3.2 gear ratio and titanium axles carbon brakes with carbon pads provide the main stopping power and even though the parachutes are used for carbon carbon brakes must be capable of stopping the one-ton vehicle from 330 miles an hour without them and of course there are no front brakes on these super slim front wheels putting even a few thousand horsepower through the tires takes an enormous toll on them at launch and they mustn't fly apart through the centrifugal forces when they reach 330 miles an hour at the finish line they must then also start the job of slowing the one-ton vehicle to a halt by the end of a track assisted by the parachutes the tyres which are made by goodyear are called ripple wall slicks and have compounds which are very very soft much softer than f1 tyres this allows them to have an incredible amount of grip on the already very sticky track but they only last for about eight one thousand foot runs before they are replaced the tyres are clamped to the wheel rims with 24 bolts to stop the wheel from slipping in the tyre and the tires are inflated to between 7 and 10 psi this and the very tall but thin side walls allow the tyres to twist and bunch up on launch this lets the tyres squat down and increase the contact patch during launch to almost 250 square inches this also reduces the tyre's diameter and the effective gearing of a final drive the twisting of a sidewall also acts to moderate the vicious delivery of torque and the energy built up in the twisted tire then releases and helps propel the vehicle off a start line with a smoother acceleration and less wheel spin as the speeds build up the tyres grow through centrifugal force and become taller and thinner which decreases the rolling resistance and increases their diameter and the final gearing pushing up the speed even more towering above the rear tyres is the massive rear aerofoil which at 300 miles an hour can produce up to 12 000 pounds or 5.4 kilonewtons of downforce which is needed to keep the tyres firmly planted on the track and reduces wheel spin as the full power of the engine is applied once the clutch locks up meanwhile at the front end the tiny by comparison front wheels and tires which are inflated to 90 psi are held onto the track by the front aerofoil which produces up to 500 pounds or 1.3 kilonewtons of downforce at 300 miles an hour ensuring the steering works and stops the whole car from flipping up and over by the time you've added the cost of the chassis rear end engine clutch electronics and data logging you've got somewhere between 250 and 300 000 for a complete car and that's without transport and crew costs about five thousand dollars in parts for a normal run with no engine blow ups and 100 per second in fuel this sport is certainly not cheap but it's probably the biggest thrill any adrenaline junk you can have this side of a rocket launch and it's still a bargain compared to formula one as the driver of a top fuel car you are putting your life in the hands of the engineers that made the parts and the mechanics of fitted them so it's good to know that they know what they're doing and understand all the technical aspects of one of the most fearsome of all racing vehicles our sponsors for this video brilliant can help you understand the skills required for engineering whether you want to start in motorsports or aim for the stars as a rocket scientist brilliant is a fun problem-solving website and app so you're not tied to the desktop and you can help develop those learning skills anywhere research shows that doing problem solving is more effective than watching a lecture brilliance approach is based on this active problem solving and learning method it's about seeing concepts visually and interacting with them so that you remember them their courses are laid out like a story and broken down into pieces so you can tackle them a little bit at a time there's no big deal here there's no tests no grades if you make a mistake along the way you just need to check out the explanations to find out more brilliant has something for everybody whether you want to start with the basics of math science and computer science or 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Channel: Curious Droid

Views: 2,219,995

Keywords: top fuel, drag racing, drag car, nitromethane fuel, nitro, paul shillito, curious droid, hemi v8, supercharged, nhra, santa pod, clutch, drag slicks, goodyear tyres, msd magneto, 14-71 roots blower, strange axle

Id: g0KTGHGXqsQ

Length: 16min 12sec (972 seconds)

Published: Fri Apr 30 2021

Reddit Comments

[u/Unusual-Echo]

How are they steered? The front wheels are off the ground snd too small to do much anyway.

[u/[deleted]]

Whenever I see these do a run, I'm pretty sure my heart pauses for the length of the run. They legit scare the hell out of me. You haven't lived until you've seen one of these in person.

[u/JustThall]

I remember 10 years ago there were already no dyno-stand to measure the output and everybody was quoting theoretical "over 9000" hp. Why here it is already 12k hp?

[u/Dirtyace]

Top fuel is so amazing and I love that this exists. Good old supercharged pushrod American v8 putting in some work.

[u/itsDisgusting]

Here are some cool facts about top fuel dragsters.

I found this article on the internet a while ago and this seems like a good place to share it.

TOP FUEL DRAGSTER FAST FACTS:

ACCELERATION PUT INTO PERSPECTIVE

​

• One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows at the Daytona 500.
• Under full throttle, a dragster engine consumes 1-1/2 gallons of nitromethane per second; a fully loaded 747 consumes about the same amount of jet fuel with 25% less energy being produced.
• A stock Dodge Hemi V8 engine cannot produce enough power to merely drive the dragster's supercharger.
• With 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into a near-solid form before ignition. Cylinders run on the verge of hydraulic lock at full throttle.
• At the stoichiometric 1.7:1 air/fuel mixture for nitromethane, the flame front temperature measures 7050 degrees F.
• Nitro methane burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from atmospheric water vapor by the searing exhaust gases.
• Dual magnetos supply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.
• Spark plug electrodes are totally consumed during a pass. After halfway, the engine is dieseling from compression plus the glow of exhaust valves at 1400 degrees F. The engine can only be shut down by cutting the fuel flow.
• If spark momentarily fails early in the run, unburned nitro builds up in the affected cylinders and then explodes with sufficient force to blow cylinder heads off the block in pieces or split the block in half.
• Dragsters reach over 300 MPH before you have completed reading this sentence.
• In order to exceed 300 MPH in 4.5 seconds, dragsters must accelerate an average of over 4 G's. In order to reach 200 MPH well before half-track, the launch acceleration approaches 8 G's.
• Top Fuel engines turn approximately 540 revolutions from light to light!
• Including the burnout, the engine must only survive 900 revolutions under load.
• The redline is actually quite high at 9500 RPM.
• THE BOTTOM LINE: Assuming all the equipment is paid off, the crew worked for free, and for once, NOTHING BLOWS UP, each run costs an estimated $1,000 per second.

The current Top Fuel dragster elapsed time record is 4.441 seconds for the quarter-mile (10/05/03, Tony Schumacher). The top speed record is 333.00 MPH (533 km/h) as measured over the last 66' of the run (09/28/03, Doug Kalitta).

Putting this all into perspective:

Lets say the you are driving the average $140,000 Lingenfelter twin turbo-powered Corvette Z06.

Over a mile up the road, a Top Fuel dragster is staged & ready to launch down a quarter-mile strip as you pass by it. You have the advantage of a flying start. You run the 'Vette hard up through the gears and blast across the starting line & pass the dragster at an honest 200 MPH. Just as you pass the Top Fuel Dragster the 'tree' goes green for both of you.

The dragster launches and starts after you. You keep your foot down hard, but you hear an incredibly brutal whine that sears your eardrums and within three seconds the dragster catches and passes you. He beats you to the finish line, a quarter-mile away from where you just passed him. Think about it---from a standing start, the dragster had spotted you 200 MPH and not only caught you, but nearly blasted you off the road when he passed you within a mere 1,320-foot-long race!

That's acceleration!