I saw this on another forum. I think it might be copied from a magazine article. Good stuff.

Top Fuel Facts

Top-Fuel Racing refers to a class of drag racing in which the cars are run on 85% nitromethane and about 15% methanol also known as racing alcohol, instead of gasoline. The nitromethane used to power the engines of top fuel dragsters costs about US$30 per U.S. gallon (US$8/L). Top Fuel dragsters use between 10 and 12 U.S. gallons (38 to 45 L) of fuel for a complete pass, including the burnout, backup to the starting line, and quarter-mile run. The engine makes about 3.4 times as much power as a similar displacement engine running gasoline.

* The engines are purpose-designed V8 engines, whose basic design is descended from the Chrysler Hemi engine. The engines can typically produce at least 8,000 horsepower (6 MW). The supercharger alone requires 1500 horsepower (1.1 MW) to turn it to generate the great intake manifold pressures for the engines. While going down the track the engines run on the verge of hydraulic lock (that is, the air-fuel mixture is compressed so much it is almost a liquid). Two spark plugs per cylinder are the rule, with some teams experimenting with three. The spark plug electrodes are completely consumed during a run, but spark ignition is not necessary after the first half of the pass, since the motor is dieseling (igniting the air-fuel mixture without the help of a spark) because of the compression and extremely hot exhaust valves. After each pass, the whole engine is taken apart and gone through, and much of it is replaced. The engine is therefore designed for quick and easy disassembly and reassembly. On average, each run costs about $2,000 - $3,000.

* These cars compete in a 1/4 mile (0.4 km) race and complete it in less than 4.5 seconds at upwards of 330 MPH (530 km/h). Top Fuel dragsters are the fastest linear accelerating vehicles in the world. A Top Fuel dragster accelerates from 0 to 100 mph (160 km/h) in less than 0.8 second, almost 11 seconds quicker than it takes a production Porsche 911 Turbo to reach the same speed. They can exceed 280 mph (450 km/h) in just 660 feet (0.2 km).

* Before their run, they do a burn-out A burn-out is done for two reasons. First, after applying some water, it heats the tires up, and secondly, it removes foreign debris from the tires. A top fueler's burnout alone can travel halfway down the track.

* At top engine speed, the exhaust gases escaping from the open headers produce about 800 pounds-force (3.6 kilonewtons) of downforce (although much more downforce is produced by the massive foil sitting over the rear wheels).

* 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 jet fuel at the same rate with 25% less energy being produced.

* At the stoichiometric (stoichiometry: methodology and technology by which quantities of reactants and products in chemical reactions are determined) 1.7:1 air/fuel mixture for nitromethane the flame front temperature measures 7050 degrees F.

* Nitromethane 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.

* 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.

* In order to exceed 300 mph in 4.5 seconds dragsters must accelerate an average of over 4G's. In order to reach 200 mph well before half-track, the launch acceleration approaches 8G's.

* Dragsters reach over 300 miles per hour before you have completed reading this sentence.

* Top Fuel Engines turn approximately 540 revolutions from light to light!

* Including the burnout the engine must only survive 900 revolutions under load.

* The red line 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 $1,000.00 per second.

* The current Top Fuel dragster elapsed time record is 4.420 seconds for the quarter mile (Doug Kalitta). The top speed record is 336.15 mph. (540.98 km/h) as measured over the last 66' of the run (Tony Schumacher).

 

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Putting all of this into perspective:

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 and ready to launch down a quarter mile strip as you pass. You have the advantage of a flying start. You run the 'Vette hard up through the gears and blast across the starting line and past the dragster at an honest 200 mph. The 'tree' goes green for both of you at that moment.

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 3 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, but nearly blasted you off the road when he passed you within a mere 1320 foot long race course.

 

 

I've always thought that was a really cool fact. One of the reasons I like drag racing so much.

NHRA has since imposed a rev limiter to slow the cars down a bit. The limiter is supposed to kick in if the motor revs over 8100 rpm after 3.5 secs I believe and it will take timing out of the engine at 50 degrees per second for the first 1/4 second or so then drop back to a rate of 25 degrees per second. They changed to add the second rate because imagine what would happen if you started retarding the timing at a rate of 50 / sec at 3.5 seconds.... and there is still another second left.... well most of the time the supercharger backfires and you get one heck of a fire.

I can't say I agree with the rev limiter because it's TOP fuel which should be an unlimited class. But I guess Goodyear is having trouble keeping up with the tire tech so that the tires will hold together for 340 mph.

Oh well......

WV

 

I really believe that standing on the side of the track for a top fuel drag is one of the most incredible things I have ever seen, heard, smelt and felt. Espescially, a night race. You really cant consider youself a true gearhead unless you have done it.

Absolutely amazing!!!

 

amen to that!!
last time i was at a drag i was like 7 or 8 that was ten years ago i still remember it like yesterday i watch a nova rip its back bumper off and a hemi challenger brake an engine mount and still make descent time.

 

I went to the Gator Nationals when I was about 9 or 10, and my most vivid memory was that during the top fuel runs, I wasn't paying attention to the cars and taking a drink of coke. When they took off, I ended up wearing that coke...