Read this through slowly and try to comprehend the amount of force produced in just under 4 seconds!
There are no rockets or airplanes built by any government in the world that can accelerate from a standing start as fast as a Top Fuel Dragster or Funny Car!
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DEFINITION OF ACCELERATION
One top fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows of stock cars at the Daytona 500.
It takes just 15/100ths of a second for all 6,000+ horsepower of an NHRA Top Fuel dragster engine to reach the rear wheels.
Under full throttle, a dragster engine consumes 1-1/2 gallons of nitro methane 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.
With 3,000 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 (stoichiometry: methodology and technology by which quantities of reactants and products in chemical reactions are determined) 1.7:1 air/fuel mixture of nitro methane, the flame front temperature measures 7,050 deg 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 1,400 deg 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. 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. (I question this statement)
The redline is actually quite high at 9,500 rpm.
Assuming all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs an estimate $1,000.00 per second.
The current top fuel dragster elapsed time record is 4.428 seconds for the quarter mile (11/12/06, Tony Schumacher, at Pomona , CA ). The top speed record is 336.15 mph as measured over the last 66' of the run (05/25/05 Tony Schumacher, at Hebron , OH ).
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 pass 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 1,320 foot long race course.
...... and that my friend, is ACCELERATION!
[Reply]
Originally Posted by GTsetGO:
Top fuel engines turn approximately 540 revolutions from light to light! Including the burnout, the engine must only survive 900 revolutions under load. (I question this statement)
The first part of that is actually pretty close to accurate. At 9,000 RPM the engine makes 150 full revolutions per second. Now you have to remember that in a traditional 4-stroke internal combustion engine each cylinder only has 1 combustion event every 2 revolutions. In a V8 a cylinder fires every 90 degrees of crank rotation, 720 degrees for all 8 cylinders to fire. So to make numbers easy, lets just say that the engine is at 9,000 RPM for a 4.00 sec pass.
9000/60 = 150 revolutions per second
150*4 = 600 engine revolutions if the engine is at 9,000 RPM for a 4.00 sec pass
Now for fun, the engine needs to spin 720 degrees for all 8 cylinders to fire, so from 600 revolutions there are 300 complete engine cycles (all 8 cylinders through all 4 strokes)
300 cycles/8 cylinders = 37.5 complete 4 stroke cycles per cylinder per pass
37.5 cycles at 4 sec is 9.375 complete 4 stroke cycles per cylinder per SECOND
If a 4 stroke cycle is finished at just about 100 milliseconds, that means the crank is spinning TWICE that since it take 2 full turns for 1 cycle. You are looking somewhere around the 50-75 milliseconds for the crank to make one complete revolution.
[Reply]
Those are amazing stats.
I was working at the Seattle Int. Raceway during the NW Nationals in the late nineties and found myself in a disscussion with a NHRA Official. We were walking along and I was intent on the conversation, not looking where We were. He turns to me and say's (Yells) "Can You Hold on for 4 and a half seconds?" I nodded and looked around. We were inbetween Cruz Pedregon and another Racer AT THE LINE! All I saw was the tree go Green and The World went white and
Fell In on Me!
:-)
I've been to Space Shuttle Launches before, But
NOTHING Was Ever THAT LOUD!! Then Guy just turned around and looked back in my direction and just Laughed at me.
The Ground Shook and it just Hammered your Entire Body! I was deaf for damn near a half hour. That was
with Two Levels of hearing protection! All I could smell for the rest of the day, was the fuel that
Didn't burn that was all over me and my uniform.
:-)
I'll always remember that.
:-)
Cheers!
:-)
slack
:-)
[Reply]