Ever wonder about the physics of a Top Fuel dragster?

[FastDoc]

I cut and pasted this off of another website but find it very interesting for all of us motorheads here. Well written little article and worth the read.

I was especially shocked to hear that the fuel/air mixture is so compressed it is on the edge of changing states of matter from gas to liquid, and when this happens it hydraulically locks the motor, which then explodes.



Ever wonder why a Top Fuel dragster gets a rebuilt engine after each run?

Stay with this - even if you aren't a 'car nut', this is stunning.


* One Top Fuel dragster outfitted with a 500 cubic-inch replica Dodge (actually Keith Black, etc) Hemi engine makes more horsepower (8,000 HP) than the first 4 rows of cars at NASCAR's Daytona 500.

* Under full throttle, a dragster engine will consume 11.2 gallons of nitro methane per second; a fully loaded Boeing 747 consumes jet fuel at the same rate but 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 lockup at full throttle.

* At the stoichiometric 1.7:1 air/fuel mixture for nitro methane 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. Which is typically the output of a small electric arc welder in each cylinder.

* Spark plug electrodes are totally consumed during a pass. After 1/2 way thru the run, the engine is 'dieseling' from compression and the glow of the 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 enough force to blow the 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, a dragster must accelerate an average of over 4 G's. In order to reach 200 MPH well before reaching half-track, at launch the 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 for, the pit crew is working for free. & NOTHING BLOWS UP, each run will cost an estimated $1,000 per second.

0 to 100 MPH in .8 seconds (the first 60 feet of the run)

0 to 200 MPH in 2.2 seconds (the first 350 feet of the run)

6 g-forces at the starting line (nothing accelerates faster on land)

6 negative g-forces upon deployment of twin 'chutes at 300

An NHRA Top Fuel Dragster accelerates quicker than any other land vehicle on earth… quicker than a jet fighter plane… quicker than the space shuttle… or snapping your fingers!!

The current Top Fuel dragster elapsed time record is 4.420 seconds for the quarter-mile (2004, Doug Kalitta). (I think the time is now closer to 4 seconds, M.)

The top speed record is 337.58 MPH as measured over the last 66' of the run (2005, Tony Schumacher).

Let's now put this all into perspective:

Imagine this...........You are driving a new $140,000 Lingenfelter twin-turbo powered Corvette Z-06. Over a mile up the road, a Top Fuel dragster is staged & ready to 'launch' down a quarter-mile s trip as you pass. You have the advantage of a flying start. You run the 'Vette hard, on up through the gears and blast across the starting line & pass the dragster at an honest 200 MPH.... The 'tree' goes green for both of you at that exact moment. The dragster departs & starts after you. You keep your foot buried hard to the floor, and suddenly you hear an incredibly brutally screaming whine that seares and pummels your eardrums & within a mere 3 seconds the dragster effortlessly catches & 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 it not only caught, but nearly blasted you off the planet when he passed you within a mere 1320 foot long race !!!!

That, my friends.....is acceleration.

[FastDoc]

But a 747 makes about 125,000 HP so I'm not sure about that comparison.

[FastDoc]

I also don't understand what is meant by this, and a related, statement:

"Top Fuel engines turn approximately 540 revolutions from light to light!"

[cheesy]

Originally Posted by FastDoc

I also don't understand what is meant by this, anda related, statement:

"Top Fuel engines turn approximately 540 revolutions from light to light!"

It might possibly mean as the 'tree' counts down.

[kelvinator]

Each revolution is the full turn of engine components between the change of lights on the tree

I love cars have a 02 Camaro 950hp. . TO much free time and a steady paycheck.

[FastDoc]

Originally Posted by kelvinator

Each revolution is the full turn of engine components between the change of lights on the tree

I love cars have a 02 Camaro 950hp. . TO much free time and a steady paycheck.

I'll bet you're single... LOL!

Marriage will consume any paycheck, especially if there are kids involved.

My poor Corvette limps along with 'only' 350 HP. Even so it has been awarded Citations Of Velocity Confirmation many times by law enforcement, ironically mostly in Idaho :-(

[SpudRider]

Thank you for contributing to the government funding for the State of Idaho, Doc.

[FastDoc]

That was a costly trip.

They should name a rest stop after me.

[SpudRider]

I agree. I think the 'FastDoc Rest Stop' is a fitting memorial.

[Weldangrind]

44 amps per spark plug! The way to win a million dollars in Top Fuel racing is to spend two million.

[katoranger]

One second of fuel is about 2 weeks in the toyota.