Cupcar

The following was sent to me by a friend and I thought this might be of interest to gearheads. I can't vouch for the facts, but if you have seen an American Top Fuel dragster in action, you have no doubt:

*One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows at the Nascar Daytona 500 grid.

* Under full throttle, a dragster engine consumes 11.2 gallons of nitromethane per second; a fully loaded 747 consumes jet fuel at the same rate with 25% less energy being produced.

* A stock Dodge Hemi V8 engine cannot produce enough power to drive the dragster's supercharger alone.

* 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 point of 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.

* Spark plug electrodes are totally consumed during a pass. After ½ way,
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.

* In order to exceed 300 mph in 4.5 seconds dragsters must accelerate an
average of over 4G's. They reach 200 mph well before half-track; initial 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 redline is actually quite high at 9500rpm.

*The Bottom Line; Assuming all the equipment is paid off, the crew worked for free, & for once, NOTHING BLOWS UP, each run costs an estimated US$1,000.00 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 333.00mph. (533 km/h) as measured over the last 66' of the run (09/28/03Doug Kalitta). 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 & 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 & blast across the starting line & past the dragster at an honest 200 mph. The 'tree' goes green for both of you at the moment you cross the starting line.

The dragster launches & starts after you. You keep your foot down hard, maintaining your 200 mph, but you hear an incredibly brutal whine that sears your eardrums & within 3 seconds the dragster catches & passes you. He beats you to the finish line, a quarter mile away from where you just passed him. Thinkabout it, from a standing start, the dragster had spotted you 200 mph & not only caught, but nearly blasted you off the road when he passed you within a mere 1320 foot long race course.

That's acceleration.......

tonytaylor

Interesting stuff, - I wonder if they are getting close to the theoretical maximium limits for internal combustion engines.
They have still some way to go to beat Sammy Miller, who went 386.26 mph in 3.583 seconds in 1994, in his rocket powered car.

RSAErick

That is freaking amazing!

I am also a big fan of live drag racing. Even moreso than F1 or CART racing, TV has no ability to do justice to what these machines are doing. You simply HAVE to see it (and hear it!!!!!!!!!!!!!!!!) to believe it.

In addition to the facts listed by Cupcar, there is one more that I had heard: Apparently the torque produced by these engines is so great, that the engine blocks twist severely during full-throttle accelation. As a result, Top-fuel dragster engines are tuned for these "load" conditions. The differences from the front of the engine to rear of the engine are supposedly quite great (valve clearance, ignition timing, etc.). Now THAT'S some torque.


Erick

Cupcar

I don't watch Nascar, are the grids 3 cars wide? If so, and the cars are at around 600-700 HP each, the first statement means around 7200 to 8400 HP!!!

Jeff Curtis

Nice fun "urban legend" of sort...do the math, the Dragster -VS.- the Vette formula doesn't add up.

Sorry to be such an egghead.

botoo

Actually the dragster, assuming the record time, will cross the finish line 17 feet ahead of the Corvette.

The grid in NASCAR is 2 cars wide, so 4,800 to 5,600 HP would be more like it.

I agree, however, you HAVE to BE THERE to appreciate it. It's worth every dollar to see it at least once....TV is nothing.

Jeff Curtis

Uh-oh...I've apparently done some mis-calculating.

I do agree with the fact that you have to be there...as I have been MANY times, it's just amazing to feel the heat from the bleachers as those funny cars launch - downright amazing.

RSAErick

I think that it goes something like this:

200 miles/hr = 200 miles/3600 seconds
200 miles/3600 seconds = 1 mile/18 seconds
1 mile/18 seconds = 0.25 mile/4.5 seconds.

It would be a good race. I'd pay money to see it!

Of course, at 964 top speed (~160 mph), it would take us a turtle-like 5.65 seconds. Only fast enough to take a Pro-stocker.

bj

I've read that the limits reached are now dependent on the tires both for dragsters and F1's. G forces experienced in a dragster surpass those in the shuttle!

Bill
90C2

Cupcar

The 8G start would have me at an 1880 pound seat weight. Now that must feel like something!!!

robmug

It is an amazing sight (and sound). They do produce in the region of 7000 hp. Stand too close and the nitro makes your eyes water!

RSAErick

Drivers have broken ribs at launch...

RSAErick

True. Not to mention your lungs burn. The stuff smells volatile.

Oddjob

>"* Under full throttle, a dragster engine consumes 11.2 gallons of nitromethane per second; a fully loaded 747 consumes jet fuel at the same rate with 25% less energy being produced. "

So thats a little over 50 gallons at the end of the 1/4 mile. How big are their fuel tanks? Same for question for the plane: say you fly non stop to China (14 hours = 50,400 seconds x 11.2 gal/sec = 564,480 gallons. Guess around 6lb/gal = 3,387,000 lbs = 1700 tons of fuel?

Most jet engines are rated in lbs of thrust, but I did see where a 747 engine is about 15000 bhp (?). So with 4 engines pushing 60,000 bhp Im not sure how that equates to 25% less energy. Hopefully they are waranteed for more more than 900 revolutions....

Interestingly, the plane weighs close to 700,000 lbs, so with 60k bhp, that is very similar to P-car power to weight: 11.7 lbs/bhp

botoo

11.2 gallons of fuel per second is too much. In 4.5 seconds that would be 50 gallons. I believe a top fuel dragster burns about 15 to 18 gallons per run.

>>Hopefully they are warranteed for more more than 900 revolutions....<<

Actually, they are not warranteed at all. They rebuild the engine, more or less, after every run.