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-   -   This puts raw acceleration into perspective! (http://forums.pelicanparts.com/off-topic-discussions/380220-puts-raw-acceleration-into-perspective.html)

cnielsen 12-01-2007 10:24 AM

This puts raw acceleration into perspective!
 
Good read but the last paragraph is the best and one that some of us could slightly begin to comprehend the sheer power of these beasts...



REAL “ACCELERATION"

One top fuel dragster with 500 cubic inch Hemi engine makes more horsepower
than the first 4 rows of stock cars at the Daytona 500. (approx - 8000 hp)

Under full throttle, a dragster engine consumes 1-1/2 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.

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, (very rich) the flame front
temperature measures 7,050 deg F. (air/fuel stoichiometric is approx - 14.7:1 on a car)

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 peak amps to each spark plug. This is essentially 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.

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 4.441 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).

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 draster 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 you, but nearly
blasted you off the road when he passed you within a mere 1,320 foot
long race course.
That, folks, is acceleration :o)

'76 911S 3.0 12-01-2007 10:37 AM

Makes my 911 seem slow (not feel, just seem) :(

WI wide body 12-01-2007 10:54 AM

Yeah, but if those dragster guys have to turn left or right they crash!

So actually they couldn't beat me thru a sub-division if I was driving a Honda Civic. ;)

don911 12-01-2007 12:35 PM

The raw power of top fuel drag racing is so over the top that it's hard to believe that's it's even possible to harness that amount of energy. Technically, it's an interesting sport but watching is so boring in my opinion. I occationally can sit through short highlights but nothing more.

Mitch Leland 12-01-2007 01:10 PM

When I was in high school in the fifties dragsters were turning a 132 MPH, they said at that time 150 MPH was the mathematical maximum a car could accelerate in a quarter mile. I don't know if that is true or not, but they've sure beat that by a long ways. By any stretch of the imagination it's big business...

nut11 12-01-2007 01:12 PM

Great read. Just incredible. Thx.

87 blk coupe

Zeke 12-01-2007 01:20 PM

And that's on 90% nitro. They used to run 98%. Where's the limit now? When will they reach 350 MPH and that many more G's? Already one top fueler retired because of stress on the eyes due to the G's (Joe Amato with detached retinas). So far, he's the only one to admit physical problems.

Hugh R 12-01-2007 03:45 PM

Watching on TV is nothing compared to being there. If you've never been you should definitely go. The pressure wave that passes through you is like nothing you've ever experienced.

Cdnone1 12-01-2007 04:29 PM

I was at the season ending event in Fontana. I had a full media pass with the blue vest so I could go wherever I wanted.
I took my camera and set up on about eight feet from where the Top Fuel launched. On the first pass as the car left it scared me so much that i ducked behind the concrete wall and covered my head. When I finally looked up everyone in the stands as well as all the other Proffessional Photographers where laughing their a$$es off of at me.
I was quite an experience.
If I can get my other computer fixed I will post some pictures I took from the start line. Like so many things, TV can not do it justice.
Steve

Formerly Steve Wilkinson 12-01-2007 04:43 PM

That text has been around for years. It's a viral that I think originally appeared in a somewhat different form in Car and Driver about 10 years ago.

But have you seen the urban-legend e-mail about what your fuel-gauge pump icon _really_ means???

Eagledriver 12-01-2007 06:38 PM

Everything there looks correct except the 8 G accel number. The theoretical limit of 150 MPH was based on a friction coefficient of 1 I believe. Since modern tire technology can exceed that and since the car has a wing for downforce the limit is much higher. It's likely that the coefficient of friction is around 3 based on the performance of the car. This means at launch it can pull 3 G's. As the speed increases and the wing starts to push down on the car the G can increase. The max G is probably in the middle of the run somewhere and would be above the average of 4.5 G. A good guess would be around 6 G and would require the downforce to be twice the car weight at whatever speed this occurs.

-Andy

trekkor 12-01-2007 07:42 PM

When they run at Sonoma, I can hear them from my house in Napa, 15 miles away.


KT

HardDrive 12-01-2007 08:30 PM

They missed one:

Top fuel dragster = 8000HP
Combined tooth count of all drag racing fans in USA = 7325


.....just pulling your chain, good read! Some amazing engineering going on.

Won 12-01-2007 11:32 PM

Quote:

Originally Posted by cnielsen (Post 3619190)
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.

I like this part!:eek:

Jeff Higgins 12-02-2007 06:03 AM

They are impressive either way you add it up. Some of the numbers in this latest version do not add up, granted, and there are some other "enhancements" made as well. Still, the real numbers are impressive enough. No need to exagerate with these cars. "Naught to 330" in just over four and one half seconds ain't bad.

I actually had the chance to wrench a little bit on a funny car back in the early '80's, back when they still had the full class deignation of "AA/FC". Strictly "amateur hour", this was a group of knuckleheads off the shop floor that would run one whenever they could pull together enough spare change to make it run. They did manage the track record in Denver one year, but that was their only claim to fame. This was when the NHRA still had enough local yokels running these things to actually give divisional points in the fuel classes. Before it got "expensive", relatively speaking. Back when they sometimes still had 32 car fields at nationals. But I digress...

These cars won't "diesel". They were just starting to run dual mags and dual plugs back then, but for different reasons than we do. It was (still is) for the redundancy; just like an airplane. It's pretty common to lose a plug on a run, and the second one gives it a chance to keep firing on that cylinder. If you lose both plugs, it drops that cylinder. You can actually see when a car does this; the exhaust pipe on that cylinder starts looking like a sprinkler. It just keeps pumping the raw fuel through it.

The part about shutting off fuel flow to cut the engine is kinda sorta true. Problem is, the driver cannot do it. The NHRA does not allow fuel control valves, nor levers to control them, in the cockpit for safety reasons. The motors run on mags and again, there is no driver accesible shut off. A crew member has to shut the car off. In the case of an aborted run, keep your eyes on the guy that walks up and shuts it off. At the end of the run, it just runs out of fuel somewhere in the shutdown area. You will see these cars wreck sometimes and rather inexplicably (seemingly) just keep running. I saw a top fuel car flop on its side after getting crossed up right out of the hole one day; it kept spinning like a top around the rear tire that was on the ground. No way to stop it; the driver just had to wait for it to run out of gas.

These machines are just so over the top they defy belief. They are now running eight gallon tanks on these cars (the guys I hung out with ran five) and they run them dry in one burnout and a single pass. The burnout uses just about a gallon of it. With that in mind, try filling an 7 gallon container in 4.5 seconds. See how many garden hoses running at full blast it takes to do that. That is the fuel flow into a nitro burning motor. The NHRA has now bumped the percent down once again in an effort to somewhat control these cars. I believe it is down to 85% now, with the rest methanol.

Anyway, drag racing as a whole is pretty damn boring. I am, however, and will remain a lifelong fan of top fuel and funny car. If you have never seen one live, go do it. You owe it to yourself. Even if you hate drag racing and everything to do with it. You have my money back guarantee; you will never see anything else like it. TV does it no justice whatsoever.

Rick V 12-02-2007 06:45 AM

Quote:

Originally Posted by Hugh R (Post 3619664)
Watching on TV is nothing compared to being there. If you've never been you should definitely go. The pressure wave that passes through you is like nothing you've ever experienced.

This is the only way to put it in perspective.

BertBeagle 12-02-2007 07:03 AM

Quote:

Originally Posted by trekkor (Post 3620015)
When they run at Sonoma, I can hear them from my house in Napa, 15 miles away.


KT

Here in Charlotte Bruton Smith (owner of Lowe's Motor Speedway) just brought the city of Concord and its leaders to their knees by threating to move if they did not let him build a major NHRA track facility on his race track property. When the city got wind of his intentions (he was already grading for the track) they moved to cancel any permits and voted not to allow a drag racing track. In the span of a few weeks that changed to the city offering him 80M (believe the number is correct) in incentives to build a drag racing track when he threatened to close Lowe's and move to another city Your post above got me to thinking about the residents who's subdivision actually will border the track!

BertBeagle 12-02-2007 07:06 AM

Quote:

Originally Posted by Wayne at Pelican Parts (Post 3620218)
BOGUS! The numbers do not add up - the text is wrong in one or more places.

The corvette travelling 200 mph covers 1,056,000 feet per hour, or 293 feet per second. In a course of 1,320 feet, the vette will take 4.5 seconds to complete that 1/4 mile.



So, the world record holder will barely beat the vette by a mere .059 seconds under this circumstance.



Nope, not going to happen according to the actual numbers listed in the text. BOGUS.

-Wayne

Even with the numbers corrected it is no less spectacular.

mattdavis11 12-02-2007 07:06 AM

When Bernstein broke 300mph at the Gator nationals in March 1992, I was in Gainesville. It seemed as if everyone had a needle in their arm after that blast down the pavement. It was unreal.http://forums.pelicanparts.com/uploa...1196612054.jpg

9dreizig 12-02-2007 07:28 AM

Quote:

Originally Posted by Wayne at Pelican Parts (Post 3620218)
BOGUS! The numbers do not add up - the text is wrong in one or more places.
-Wayne

What are you an MIT grad ?? Oops ok sorry LOL

Damn it was fun believing it while we could..
What about the easter bunny Wayne?? real or urban myth ??


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