OT - Drag Racing - Unimaginable Acceleration

With the NHRA Winternationals in my backyard, I thought I'd pass this along.

Dave

Unimaginable Acceleration

a.. One Top Fuel dragster's 500-cubic-inch Hemi engine makes more horsepower than the first four rows of the Daytona 500. b.. A stock Dodge Hemi V-8 engine cannot produce enough power to drive the dragster's supercharger. c.. 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. d.. At the stoichiometric 1.7:1 air-fuel mixture for nitromethane, the flame front temperature measures about 7000 degrees Fahrenheit. e.. Nitromethane burn yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, separated from atmospheric water vapor by the searing heat of the exhaust gases. f.. The dual magnetos supply 44 amps to each spark plug. This output is the equivalent of an arc welder in each cylinder. g.. Spark plug electrodes can he totally consumed during a single pass. After half-distance, the engine is dieseling from compression plus the glow of exhaust valves at 1400 degrees Fahrenheit. The engine is shut down by cutting the fuel flow. h.. If a spark plug fails early in the run, unburned nitro can build up in the affected cylinder and explode with sufficient force to blow the cylinder head off in pieces or split the cylinder block in half. i.. In order to exceed 300 mph in 4.5 seconds, Top Fuel dragsters must accelerate at an average of more than 4 g's. In order to reach 200 mph before half-distance, the launch acceleration approaches 8 g's. A Top Fuel dragster reaches more than 300 mph before you have completed reading this sentence. j.. With a redline that can be as high as 9500 rpm, Top Fuel engines turn approximately 510 revolutions from light to light. Including the burnout, the engine needs to survive only 900 revolutions under load. k.. Assuming that oil of the equipment is paid off, the crew works gratis, and nothing breaks, each run costs an estimated $1000 per second. l.. The current Top Fuel dragster elapsed time record is 4.441 seconds for the quarter-mile. (October 5, 2003, Tony Schumacher). The top speed record is 333.25 mph as measured over the last 66 feet of the quarter mile November

9, 2003, Doug Kalitta).

a.. Putting all of this into perspective: you are driving the average $140,000 Lingenfelter twin-turbo Corvette Z06. More than a mile up the road, a Top Fuel dragster is staged and ready to launch down a measured quarter-mile as you pass. You have the advantage of a flying start. You run the Vette 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, but you hear a brutal whine that sears your ear drums, and within three seconds, the dragster catches you and beats you to the finish line, a quarter-mile from where you just passed him. From a standing start, the top fueler spotted you 200 mph and not only caught you but nearly blasted you off the road when he passed you within a mere 1320 feet.

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Reply to
TeamCasa
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Holy Crap. :)

Reply to
Fly-by-Night CC

The lateral thinker in me is saying "don't do this activity with false teeth or you'll choke to death". While you're at it, toss the wig and tape the glasses on; also, anyone with a butt plug gets to clean their own car.

Reply to
Groggy

On Mon, 23 Feb 2004 21:29:07 -0800, "TeamCasa" wrote: [snip]

| You have the advantage of a flying start. You run |the Vette 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, but you hear a brutal whine that sears your ear drums, and within |three seconds, the dragster catches you and beats you to the finish line, a |quarter-mile from where you just passed him. From a standing start, the top |fueler spotted you 200 mph and not only caught you but nearly blasted you |off the road when he passed you within a mere 1320 feet.

Not the same numbers, but I recall a race here in Tucson (DMAFB) about

1960 when one of my dirt track buddies brought his super-modified dirt track car to the drag strip and ran a similar race with the Speed Sport Roadster.

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course the dirt car had the wrong rear end gear for this and only ran about 100 mph flat out but the roadster reeled him in about midtrack. Lyle and Red where way ahead of their time. Never will forget the sound of that car and the tears running down my cheeks from the nitro fumes.

Reply to
Wes Stewart

Hey, the Winternationals are in my back yard too!! I can almost throw rocks at those rails from where I'm at. Heard 'em running on Thursday. Too bad they were rained out.

Reply to
Mark and Kim Smith

Not quite.

v = a * t

300mph = 440 fps 440 fps / 4.5s = 100 feet/sec/sec approx, slightly over 3 g. Still impressive, though.

Not even close.

s = a * (t^2) = v * t half-distance = 660 feet

200 mph = 293 feet/sec 660 feet = 293 feet/sec * t t = 2.25 sec t^2 = 5.07 sec^2 660 feet / 5.07 sec^2 = 130 feet/sec^2 = 4g approx

-- Regards, Doug Miller (alphageek-at-milmac-dot-com)

For a copy of my TrollFilter for NewsProxy/Nfilter, send email to autoresponder at filterinfo-at-milmac-dot-com

Reply to
Doug Miller

The real human cannonballs!

Barry

Reply to
B a r r y

Now this is why I love drag racing over any other motor sport! Thats some amazing stuff Casa, thanks for sharing it with us.

Jim

Reply to
James D. Kountz

Geezus...................................................................... .............

Reply to
Larry C in Auburn, WA

While googling around for a confirmation of the acceleration, I came across a Popular Science article where they talk about the load at launch being about 4.5 g.

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article goes on to say that they don't really know how much horsepower the nitro engines produce. They've never put a top fuel nitro engine on a dyno. The best estimate from extrapolations of dyna tests on alcohol are

6000-7000HP.

todd

Reply to
todd

ayup. 4g's for 4.5 seconds gives an end speed of just under 400 mph.

WUPS! have to disagree

That's an _average_ acceleration.

Which assumes constant acceleration.

Real-world, the acceleration is _not_ constant.

It decreases with time.

If one assumes 8g at 'launch', decreasing linearly to 3+ g by the end of the first second, and constant 3+ g to the end of the quarter-mile, the elapsed time is approx. 4.5 seconds, and final velocity is approx 330MPH.

This is consistent with documented hardware performance.

It doesn't precisely match the stated conditions, in that one is past the halfway mark at 2.2 sec, with a speed of 242 mph. This is _not_ unexpected, because the rate of decrease of acceleration (hows that for confusing? :) is not constant; at high acceleration, the acceleration bleeds off faster than when it's lower.

8+ g _initially_ (i.e., 'at launch') *is* believable. It's a 'peak' value, not a 'sustained' one.
Reply to
Robert Bonomi

Doug, Your calculations remind me of the time when my Caltech (applied physics) professor determined that no matter how much horsepower a top fuel vehicle produced, it was mathematically impossible to cover the 1/4 mile any faster than 6.2 seconds. (1974)

Dave

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Reply to
TeamCasa

Mark and Kim, I have been doing some work at Brackett Airport lately. I hope Saturday and Sunday Sunday Sunday will be dry! Dave

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Reply to
TeamCasa

"todd" wrote in news:XN-dnTBDF snipped-for-privacy@comcast.com:

Note that to get a dyno value requires that the engine remain running for several seconds, considerably longer than a top fuel engine is able to run (the average life of such an engine is less than 1000 revolutions).

John

Reply to
John McCoy

Ahhh, no sweat. My '50 Chevvy coupe/220 cu in Jimmy could've beat it. Off a cliff. With a 20 ft head start. NO prob. twitch, jo4hn

Reply to
jo4hn

I finally got it! Now I know why sex is dangerous and racing is safe! (it used to be the other way around)

Reply to
Mark Hopkins

Knew a family that had a semi-pro track near/behind his house. Said he wondered why the property was so cheap. Didn't take long for him to figure it out the first fri. night. Just saw History Channel's take on Drag racing wow stuff. Concluded that the allowance of straight NO system along with computer controlled fuel/booster injection the current speed record could be blown out of the water.

Reply to
Young_carpenter

For those following this thread that have never seen the Top Fuels cars run in person, I heartily encourage you to take any opportunity to do so.

Anyone with any interest in technology or "neat stuff" in general MUST witness this spectacle at least once in your life. Even if you don't care for racing in general, you will be amazed at what you see.

There are few things in life that will truly make you "not believe your eyes", but this is one of them. My first time, I felt like I was watching a cartoon.

The whole sport is a testimony to what can be achieved when technology, creativity and LOTS and LOTS of money are focused on a singular goal. Your beer dollars at work...

Waaaaayyyy Coooooolllllll!!

Reply to
Tom

I recall an article--vaguely, mind you--in Hot Rod Magazine back when it was a couple, three years old that made the point that, IIRC, anything over 140 or

150 mph in the quarter mile was impossible. That was shredded within a year, I think. We're kicking around somewhere in the early '50s here, so figure most running was done with flathead V8s and OHV straight 6s at the time. It was also done with stock tires, since gluey slicks holding almost no air were a long way from being developed. I remember dragging with snow tires we buffed down to near blad states to get a wider profile and that was several years later.

I see now the big deal in motorcycles is the "naked" look. No fairing. Jeez, how things do change. That's the way they ALL came when I was younger.

Charlie Self "Health food makes me sick." Calvin Trillin

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Reply to
Charlie Self

I agree, it's truely amazing in person! I went to high school in West Covina and it was a rite of spring time to hear the cars running for the Winter Nationals. By junior year we started making it a tradition do ditch school on qualifying day and go over and watch. Somehow we got pit passes on time and got within 30 feet of the burn out area. The sound these things produce is increadable! With full hearing protection on, you still hear it through the vibration of your skelatal system. Your head vibrates at the sound frequency, it's wild!

Bernie Trying to get back from memory lane and return to adulthood in NY.

Reply to
Bernie Hunt

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