Acceleration Put Into Perspective

* One Top Fuel dragster 500 cubic-inch Hemi engine makes more horsepower than the first 4 rows at the Daytona 500.
* A stock Dodge Hemi V8 engine cannot produce enough power to merely drive the dragster's supercharger.
* 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. This is the output of an arc welder in each cylinder.

* Spark plug electrodes are totally consumed during a pass. After 1/2 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.

* Dragsters reach over 300 MPH before you have completed reading this sentence.

* In order to exceed 300 MPH in 4.5 seconds, dragsters must accelerate an average of over 4 G's. In order to reach 200 MPH well
before half-track, the launch 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 off, the crew worked for free, & for once, NOTHING BLOWS UP, each run
costs an estimated $1,000 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 333.00 MPH (533 km/h) as measured over the last 66' of the run (09/28/03, Doug Kalitta).

Putting this all into perspective:

You are driving the average $140,000 Lingenfelter twin-turbo powered Corvette Z06 (or a Fiero) . 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 and blast across the starting line & pass the dragster at an honest 200 MPH. The 'tree' goes green for both of you at that moment.

The dragster launches & starts after you. You keep your foot down hard, 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. Think about 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!

That's acceleration!
**********************************

Although I've seen this before, I thought it was interesting reading. I'm not into drag racing but, I have to respect the folks that can build a car (dragster) with that kind of power.
------------------
Ron

It's the Soldier, not the reporter
Who has given us the freedom of the press.
It's the Soldier, not the poet,
Who has given us the freedom of speech.
It's the Soldier, not the politicians
That ensures our right to Life, Liberty and the Pursuit of Happiness.
It's the Soldier who salutes the flag,
Who serves beneath the flag,
And whose coffin is draped by the flag.

[This message has been edited by blackrams (edited 01-27-2008).]

For a time one of the records was held by a funny car(I can't remember whether it was top speed or ET) even though the funny cars must weigh 200 lbs. more than a top fuel car and are no more than front engine dragsters(a disadvantage)and have to contend with wind drag because of that body.Why are alcohol cars (and that includes nitro cars that are naturally aspirated) considered sportsman classes and pro stock cars and motorcycles along with the blown fuel machines called pro classes?

quote Originally posted by blackrams: * Under full throttle, a dragster engine consumes 11.2 gallons of nitro methane per second; a fully loaded 747 consumes jet fuel at the same rate with 25% less energy being produced.

This sounded a little off to me. I did a little bit of research.

quote Wikipedia: Gasoline provides about 42-44 MJ/kg whereas nitromethane provides only 11.3 MJ/kg.

Jet fuel is closer to gasoline than nitromethane. Oxygenated fuels do consume less air and burn "cleaner" but they also have lower energy densities. That's one reason alcohol fuels haven't taken off in general automobile usage just yet.

I'd have to do the calculations to compare the energy created by a 747 to that of a dragster. But I will tell you that the comparison is misleading.

From AntiKev

"I'd have to do the calculations to compare the energy created by a 747 to that of a dragster. But I will tell you that the comparison is misleading".

Who cares?

I do :P.

quote Originally posted by hugh: From AntiKev "I'd have to do the calculations to compare the energy created by a 747 to that of a dragster. But I will tell you that the comparison is misleading". Who cares?

see that little button on the upper right that says "quote"?

To each his own !

quote Originally posted by blackrams: ... the fuel mixture is compressed into a near-solid form before ignition. Cylinders run on the verge of hydraulic lock at full throttle.

This blatant hyperbole destroys the credibility of the entire piece. (What is the triple-point of air? I don't know, but I highly doubt that it can be reached in a real-world dragster engine.)

quote Originally posted by hugh: Who cares?

Again, it brings into doubt the credibility of the entire piece. What a top-fuel dragster actually does is amazing enough in itself, without having to embellish it by introducing false information.

[This message has been edited by Marvin McInnis (edited 01-28-2008).]

OK, Sorry guys, I have removed the "questionable" parts and will delete the whole thing if you'd prefer. I accepted what I received as factual, never crossed my mind to check it all out. I reprinted this from another source and honestly found it to be entertaining and just pretty cool as to what they can do with those motors. Didn't think anyone was going to check out and verify the details or question them myself. Guess I was wrong on that one. Oh well, so much for what I thought.

------------------
Ron

It's the Soldier, not the reporter
Who has given us the freedom of the press.
It's the Soldier, not the poet,
Who has given us the freedom of speech.
It's the Soldier, not the politicians
That ensures our right to Life, Liberty and the Pursuit of Happiness.
It's the Soldier who salutes the flag,
Who serves beneath the flag,
And whose coffin is draped by the flag.

[This message has been edited by blackrams (edited 01-27-2008).]

quote Originally posted by Marvin McInnis: Again, it brings into doubt the credibility of the entire piece. What a top-fuel dragster actually does is amazing enough in itself, without having to embellish it by introducing false information.

Other than your obvious disbelief,what do you attribute your expertise to.Blackrams post was from a source of information that he considered accurate.Unless you can show his post to be inaccurate you should withhold comment.

quote Originally posted by hugh: Other than your obvious disbelief,what do you attribute your expertise to.Blackrams post was from a source of information that he considered accurate.Unless you can show his post to be inaccurate you should withhold comment.

Hugh,

If I wasn't so busy I'd do the calculations to prove it either way. I just don't have the time to.

dang ya'll is testy.

quote Originally posted by blackrams: OK, Sorry guys ...

My apologies. I did not intend to criticize or hijack your thread. The interesting piece you posted has been circulating around the Internet for a few years, and it has become "embellished" along the way. My problem is just that I find fact more impressive than fantasy.

quote Originally posted by hugh: Other than your obvious disbelief,what do you attribute your expertise to.Blackrams post was from a source of information that he considered accurate.Unless you can show his post to be inaccurate you should withhold comment.

I try never to confuse credentials with competence, so all I will say along those lines is that my formal education was in the physical sciences and engineering. I will accept your challenge to authoritatively refute the claims in the original piece that "the fuel mixture is compressed into a near-solid form before ignition. Cylinders run on the verge of hydraulic lock at full throttle," subject to two conditions:

1) that you agree to present technically sound information to support those claims, and

2) that if I am successful you do not respond with a dismissive, "Who cares?"

Fair enough?

Here's a background citation to get us started. My next (and final) challenge is to find and post the physical properties and a phase diagram for air (or for nitrogen and oxygen if can't find that information for air).

[This message has been edited by Marvin McInnis (edited 01-28-2008).]

Marvin,
No problem, I'm guilty of embleshing this one myself, as you can see in the quoted sentence. But in all honesty, I thought someone would catch it.

quote Originally posted by blackrams: You are driving the average $140,000 Lingenfelter twin-turbo powered Corvette Z06 (or a Fiero) .

Obviously, no one considered (or a Fiero) an emblishment. So, I am guilty of furthering the comparason between the obviously
comparable vehicles.

------------------
Ron

It's the Soldier, not the reporter
Who has given us the freedom of the press.
It's the Soldier, not the poet,
Who has given us the freedom of speech.
It's the Soldier, not the politicians
That ensures our right to Life, Liberty and the Pursuit of Happiness.
It's the Soldier who salutes the flag,
Who serves beneath the flag,
And whose coffin is draped by the flag.

[This message has been edited by blackrams (edited 01-28-2008).]

Marvin----Fair enough!

Except for the following:

#1 I am not technically competent ,so anything I might say can(and should be)considered hearsay.
#2 Whether or not you are successful,I will not say who cares.After all when someone puts effort into proving or disproving something ,who is anyone to say "who cares"?

Antikev You must have cared enough to comment.My "who cares"was wrong,and I apologize for poor wording.If you have ever gone to a national event where the big boys are running you want to believe anything that is said about them.I have been to a few events and believe me there is nothing compares to that experience.

quote Originally posted by blackrams: OK, Sorry guys, I have removed the "questionable" parts and will delete the whole thing if you'd prefer. I accepted what I received as factual, never crossed my mind to check it all out.

Unless every fact has been certified by an independant government laboratory, you'll need to delete the entire post to please some people.
It's obvious they're making claims they can't support. Turning water into a solid and finding the triple point, yet it refers to hydraulic lock. It's clearly an attempt to mislead the reader.

I thought it was an enjoyable read. Thanks for the post.

quote Originally posted by hugh: I have been to a few events and believe me there is nothing compares to that experience.

Wait!!! I know I'm getting old but I definately remember having sex and I'm thinking it was a better experience than drag racing. It also lasted longer.
ANYONE that thinks I'm wrong, please raise your hands and identify yourself.

------------------
Ron

It's the Soldier, not the reporter
Who has given us the freedom of the press.
It's the Soldier, not the poet,
Who has given us the freedom of speech.
It's the Soldier, not the politicians
That ensures our right to Life, Liberty and the Pursuit of Happiness.
It's the Soldier who salutes the flag,
Who serves beneath the flag,
And whose coffin is draped by the flag.

quote Originally posted by blackrams: I know I'm getting old but I definately remember having sex and I'm thinking it was a better experience than drag racing. It also lasted longer.

But have you ever tried sex in a top-fuel dragster? It would probably be even more physically challenging than in a Fiero, and I agree that the 4.441 second E.T. would definitely be a downer.

.

[This message has been edited by JazzMan (edited 12-08-2008).]

quote Originally posted by hugh: I have been to a few events and believe me there is nothing compares to that experience.

I should have said outside a bedroom or car.

OK ... here we go. First, here are the relevant physical properties of dry Air, conveniently posted on the Internet in both English and Metric/SI units. The most important property is the "Critical Point" (not the "Triple Point" I incorrectly referred to in an earlier post), at a Critical Temperature of -221 F (-141 C, or 132 K) and a Critical Pressure of 547 psia (3.77 MPa, or about 37.2 atmospheres). The Handbook of Chemistry and Physics gives similar values for Nitrogen and Oxygen, so we can conclude that these values for Air are accurate enough for our purposes.

The importance of the Critical Point is that at temperatures above the Critical Temperature air will exist either as an ordinary gas (when below the Critical Pressure) or as a "supercritical fluid" (when above the Critical Pressure), both of which phases are compressible. (It is possible for Air to go solid at extremely high pressures ... just as it's possible for ordinary carbon to be pressed into diamond ... but as we shall see the pressures required are much higher than achievable in even a dragster engine.)

Next, here is a phase diagram for Nitrogen (from the University of Washington). The black dot in the upper right quadrant of the diagram marks the Critical Point. As we have already seen, the physical properties of Air will be very similar:



Now, what will be the pre-combustion temperatures and pressures in a supercharged dragster engine? The temperature is easy; we don't have to know it exactly, just that it will clearly be higher than 100 F ... which is already more than 300 F above the Critical Temperature, and way off the right side of the phase diagram.

Estimating the pre-combustion pressure in a dragster engine requires a little more thought. A supercharged engine's compression ratio will almost certainly be 10:1 or less. But what about the supercharger itself? The highest boost pressures I'm familiar with were in WW-II combat aircraft, more than 75 inches of Mercury (or ~3 atmospheres), but dragsters certainly run higher than that ... so let's just triple it to 10:1 (10 atmospheres). That would yield a computed maximum cylinder pressure of 10:1 x 10:1, or 100 atmospheres (1470 psi) prior to combustion.

Finally, let's examine the two claims in question:

" ... the fuel mixture is compressed into a near-solid form before ignition." Referring to the phase diagram, you can see that even a pressure of 100 atmospheres is well below the solidus point of Nitrogen at any temperature above about 100 K (-280 F). Thus the air at an actual dragster's operating temperature will be nowhere close to "near-solid form."

"Cylinders run on the verge of hydraulic lock at full throttle." "Hydraulic lock" would require that the air be an incompressible fluid ... i.e. in liquid form. Again refer to the phase diagram. The actual dragster operating point is going to be well into the "Supercritical Fluid" range, where the air is still fully compressible.

Q.E.D.

As an afterthought, the more empirically inclined might want to consider this: Air cylinders used for underwater diving (e.g. "scuba") are typically pressurized to 2640 psi (187 atmospheres) at temperatures significantly below those inside a dragster engine, and they do not encounter "near-solid form" or "hydraulic lock."

And yes, the airplane will fly!

[This message has been edited by Marvin McInnis (edited 01-28-2008).]

quote Originally posted by JazzMan: Heh, I though hydrogen burned in the UV part of the spectrum? It's fairly invisible to the naked eye.

I think you're correct (no research, though) ... but I figured that I'd already picked enough nits for one thread.

[This message has been edited by Marvin McInnis (edited 01-28-2008).]

quote Originally posted by Marvin McInnis: I think you're correct (no research, though) ... but I figured that I'd already picked enough nits for one thread.

He is, that's why the main engine exhaust of the Space Shuttle is almost completely clear [ref: here].

Marvin, thanks for that, if I didn't have my head buried in HVAC, Ceramics and CFD books right now (I'm about a week behind already and the semester just started) I'd have dug up that info myself. I happen to have a thermodynamics textbook next to me collecting dust :P.

quote Originally posted by AntiKev: He is, that's why the main engine exhaust of the Space Shuttle is almost completely clear [ref: here]. Marvin, thanks for that, if I didn't have my head buried in HVAC, Ceramics and CFD books right now (I'm about a week behind already and the semester just started) I'd have dug up that info myself. I happen to have a thermodynamics textbook next to me collecting dust :P.

Yeah, but have you had sex in a Top Fuel Dragster while hurlting down the strip? That'll knock the dust off of yer Thermodynamics Text.
Waiting for the chute to pop?

------------------
Ron

It's the Soldier, not the reporter
Who has given us the freedom of the press.
It's the Soldier, not the poet,
Who has given us the freedom of speech.
It's the Soldier, not the politicians
That ensures our right to Life, Liberty and the Pursuit of Happiness.
It's the Soldier who salutes the flag,
Who serves beneath the flag,
And whose coffin is draped by the flag.

quote Originally posted by AntiKev: He is, that's why the main engine exhaust of the Space Shuttle is almost completely clear [ref: here].

That's a cool picture!

Know of any more like this?

.

[This message has been edited by JazzMan (edited 12-08-2008).]

My new favorite smiley

quote Originally posted by Jake_Dragon: My new favorite smiley

i knew it was gonna turn out like that when Hugh drew a gauntlet on Marvin

Originally posted by blackrams:

... the fuel mixture is compressed into a near-solid form before ignition. Cylinders run on the verge of hydraulic lock at full throttle.

quote Originally posted by Marvin McInnis: Again, it brings into doubt the credibility of the entire piece. What a top-fuel dragster actually does is amazing enough in itself, without having to embellish it by introducing false information.

they inject so much nitro into the motors that Cylinders run on the verge of hydraulic lock at full throttle. not the air being compressed to a solid/liquid form just there is so much fuel in there

------------------
Question wonder and be wierd
are you kind?

quote Originally posted by buddycraigg: i knew it was gonna turn out like that when Hugh drew a gauntlet on Marvin

As far as I am concerned, Hugh and I are straight now. Yea ... we old guys can get cranky sometimes.

here is the "top Fuel Numbers" from motortrend.

http://www.motortrend.com/f...502_top_fuel_numbers

------------------

My Photography
My Designs
87 Fiero GT 5-speed.
99 CSVT 5-speed.On life support, waiting its fate
99 Accord 5-speed (Annonomity)

29 Minutes it takes to tear down and rebuild a Top Fuel engine between rounds. Each engine is rebuilt 184 times a year (if the driver goes to the final round at every race).

takes me that long to change oil!

quote Originally posted by blackrams: * Top Fuel engines turn approximately 540 revolutions from light to light! * Including the burnout, the engine must only survive 900 revolutions under load.

You guys are arguing the complicated stuff, yet nobody questions this?

quote Originally posted by Patrick: You guys are arguing the complicated stuff, yet nobody questions this?

i thought that was in thousands

quote Originally posted by buddycraigg: i thought that was in thousands

Perhaps, but why wouldn't it simply be stated properly?

You think maybe there was a shortage of zeros when the original article was written?

from justa6's link:

569
Number of times the engine's crankshaft turns during the entire quarter mile. Each intake valve opens 284 times.

quote Originally posted by ray b: they inject so much nitro into the motors that Cylinders run on the verge of hydraulic lock at full throttle. not the air being compressed to a solid/liquid form just there is so much fuel in there

This is exactly what I thought when I read it the first time. So much liquid FUEL, near hydro lock.

Kevin

quote Originally posted by Patrick: You guys are arguing the complicated stuff, yet nobody questions this?

Elementary, my dear Patrick,
9000 rpm /60sec = 150 rev/sec
150 rps x 4.4 sec = 660 revolutions

I had to run the math myself to believe it.
Uh, no offense, Hugh, just looked odd.
PS. Lambo beat me to it, BTW.
Slow typists can't claim fame around here!

[This message has been edited by TennT (edited 01-29-2008).]

Testing, test, test, 1,2,3, (pop, pop, pop), is this thing turned on?

Kevin