ENGINES THAT MAKE 7,000 HORSEPOWER

We take a close look into the technology involved in Top Fuel racing, revealing some incredible
performances, facts and figures – powered by major sponsors’ money, and computers


Today’s Top fuel dragster can be the deepest money pit of all times or the most exhilarating drive you could ever experience 

We explain some of the facts and figures that will blow your mind and the three hundred
and seventy five thousand or so bucks in that account to purchase your weekend car

A spare engine complete with blower and  goodies can set you back in the region of $75,000

 Typical running costs, allowing for fuel and wear and tear on the tyres, clutch parts and engine innards such as valves, pistons and bearings, will work out at approx $11,000 per run!

The mighty slicks, costing a thousand bucks apiece, are good for maybe five hard passes.
Fuel costs are around $20 per gallon -15 gallons a round all to give that 7000 hp


Top Fuel racing is rocket science

Space – Launch = G-Forces
Did you know a Top Fuel Dragster will have a hit 300mph before you finish reading this sentence?

Imagine you’re racing your ‘06 C6 corvette against a Top Fuel car over the quarter mile. You have the advantage of a flying start and after shifting up through the gears you’re able to blast across the start line, past the stationary fueler, at 200mph, at this moment; the dragster launches and comes after you. Your foot is hard to the floor, you hear an incredible brutal whine searing your eardrums and within seconds the dragster has caught and passed you. No contest. You’ve lost.

From a standing start, the fueler has covered the quarter mile in 4.5 seconds, with a terminal speed in excess of 300mph.
It reached 100mph in less than one second and by the eighth mile, or 660ft, the dragster was doing around 270mph. Its average acceleration was about 3,4 g, though in reaching 200mph well before half track, the initial figure was closer to 5.5g. This is greater than a space –shuttle launch at 3g. On the subject of G-forces, typical deceleration at the top end, courtesy of twin chutes, is a retina -detaching 5g, the condition that led to the retirement of the legendary “Big Daddy” Don Garlits from Top Fuel racing.

The current (backed up) NHRA Top Fuel elapsed time record for the quarter mile is 4.428-seconds, set by Tony Schumacher at the Auto Club Finals in 2006. A year earlier he attained the fastest-ever Top Fuel terminal speed at 337.58mph. To achieve these figures the engine has to peak at around 8,500rpm – a figure which comes from post-run data readouts because the cars have no rev counters.

THOUSANDS OF HORSES  seven to eight thousand horsepower
Top Fuel dragsters no longer run the likes of ex-truck Dodge hemi engines rebuilt to racing spec.
Todays engines have  500 cubic-inches of scientifically-designed, aluminum-encased energy that will kick-out more horsepower than can be mustered in total by the first eight rows of NASCAR stockers at Daytona.

At seven to eight thousand horsepower = One thousand horses per cylinder. Wow, that’s a whole prairie of Mustangs!
It’s said that a stock hemi engine would not produce sufficient power to drive the fueler’s supercharger, which requires around 1,100hp, depending on the setup.

TWO GALLONS A SECOND? GULP!
Fuel consumption. Thought you wouldn’t ask. Under full throttle, a Top Fuel car consumes two imperial gallons of 90 per cent nitro-methane per second. This is comparable with the fuel burn of a fully loaded Boeing 747, which with its four turbofan engines on take-off power will gulp a couple of (imperial) gallons of Jet- A-1 every one and half seconds. Incidentally, jet fuel creates about four times the energy of nitro-methane, so that Jumbo’s “power pods” are pushing-out something in the region of 32,000 shaft horsepower all together.

AN EAR BASHING UNEQUALLED
Don Garlits knows the score. He says real fans don’t hear the fuelers with their ears,
they hear them with their bones. “And their bones will still be shakin’ when their six feet under!”

Talking about shaking, the NHRA once had seismologists out on the start line to record the effect of a pair of Top Fuelers launching. Did the earth move for them? How about a measurement of 2.3 on the Richter scale? So, not only can you hear those ground-pounding missiles with your bones, you can feel them with the soles of your feet.

TYRES THAT GROW, AND CHANGE GEAR 
A dragsters 17 inch wide, 36 inch diameter, rear slicks grow taller by as much as 4½inches during a run due to centrifugal force, hardly surprising since they operate with a pressure of just 4-5psi, have to absorb around 4,500ft–lb of torque and will reach around 133 revolutions per second by the time the car goes through the timing traps at the end of the strip. The tyres’ growth also acts as a constantly-changing final drive ratio, in other words providing a higher ratio at the end of the run.

 The “rotational inertia” of the tyres delivers an enormous amount of down force on to the car. Because the wheel rim spins faster that the tyre, this causes the sidewall to wrinkle at the bottom. Once the slick “tread” reaches the rear part of the contact patch on the track, it speeds up to catch up with the rest of the wheel rim. This momentum causes great forces that are hugely responsible for the incredible launch-acceleration times. After that, acceleration is down to engine torque. All very complex to the uninitiated, but at least we can now understand why the slicks are screwed to the wheel rims.

WINGS AND THINGS




  Three wings
are better than one!

Just ask the Red Baron. He got there  first, and that’s what counts in drag racing too. We know dragster rear wings are there to keep the driving wheels in contact with the track, but the primary purpose of  a front wing is to keep the car from pitching up and flipping over. Because rear wings are mounted as far aft as possible, there is a tendency for the front wheels to be lifted off the track surface due to weight transfer and the drag of the wing. The front wing’s down force enables the driver to retain directional control. However, its not just a matter of adding wings and saying a prayer, the shape and structure of rear wings in particular…now mostly made of carbon fibre or Kevlar… is a result of some very sophisticated scientific calculation and research, including the involvement of NASA.


Experiments on
multi-element wings

by the aviation industry many years ago….. including the UK’s Handley Page Company….. proved they were more efficient at providing lift than single-element wings. Aircraft, of course, need lift to fly, but dragsters want to hug the track, or dig in. For this reason the dragster wing is mounted upside, creating down force or “negative lift” The governing National Hot Rod Association has set rules and limitations that must be met with regard to the type, size and position of rear wings,
 

which also must be locked in place so as to prevent any potentially-dangerous adjustments during a run. In simple terms, aerodynamics call for a wing providing maximum down force to be perhaps three feet wider than used, but the NHRA limits the permitted surface area. The main reason the span is kept to the width of the car or less is because id any part of the car crosses the centerline, the driver is disqualified.


Eight tons of down force

state-of-the-art Top Fuel dragster wings produce some eight tons of down force 330mph, which means in theory you could run the car upside down in a tunnel… assuming you could get it up there in the first place!! In the same way “winglets” on modern passenger airliners enable them to improve fuel economy  and extend their range by tidying-up the disruptive airflow found at the end of a conventional wing, the addition of endplates on dragster rear wings produces vast improvements in the down-force-to-drag-ratio. Perfecting the exact shape of the endplates came about largely due to the involvement and very serious analysis by a NASA flight institute.


 

In conclusion, Top Fuel racing obviously cannot be described as  “Brute force and bloody ignorance” In truth, it’s almost rocket science.

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