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Definition of Acceleration
Hellfire - 30/8/07 at 02:30 PM

One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows of NASCARS at the Daytona 500.

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 for 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 vapour 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 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.

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 estimated $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).

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 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 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!

Phil

[Edited on 30-8-07 by Hellfire]


locoboy - 30/8/07 at 02:42 PM

Quite staggering,

I Still think they should go BEC though LOL


cadebytiger - 30/8/07 at 02:54 PM

i have no words!


David Jenkins - 30/8/07 at 03:00 PM

I'd seen the first bit before, but this one doesn't mention the bit about how much the crankshaft twists up when the engine revs are raised...

I hadn't seen the second part, about a car passing at 200mph.


02GF74 - 30/8/07 at 03:07 PM

yeah, but let's face it, the are sh%t going round corners.

(BTW it would take you 4.5 sec to cover 1/4 mile at 200 mph)

slightly off topic. how fast do passenger planes accelerate prior to take off?


Incidentaly, that ^^^ is not a definition of acceleration but an example of acceleration

[Edited on 30/8/07 by 02GF74]


nick205 - 30/8/07 at 03:12 PM


MikeR - 30/8/07 at 03:13 PM

Just proves to me a properly sorted car engine is far superior to a bike engine.


nib1980 - 30/8/07 at 03:16 PM

thats odd because i was always taught that it was, The rate at which an object's velocity changes with time.

maybe i'm just being picky


smart51 - 30/8/07 at 03:17 PM

quote:
Originally posted by MikeR
Just proves to me a properly sorted car engine is far superior to a bike engine.


Your idea of properly sorted is an engine whose life expectancy is 900 revolutions?


dan__wright - 30/8/07 at 03:17 PM

quote:
Originally posted by MikeR
Just proves to me a properly sorted car engine is far superior to a bike engine.




depends what you class as superior, you have cost, reliability, lifespan etc to take into consideration.

also, with the amount of money that goes into them, if you were to spend that much money on a bike engine im sure you would come away with something pretty special.


clutch_kick - 30/8/07 at 03:24 PM

quote:
slightly off topic. how fast do passenger planes accelerate prior to take off?



I'll time it this evening and try to work it out ... but the take off speed for a loaded A320 would be close to about 160Knots , that is about 184mph

[Edited on 30/8/07 by clutch_kick]


02GF74 - 30/8/07 at 03:25 PM

quote:
Originally posted by nib1980
thats odd because i was always taught that it was, The rate at which an object's velocity changes with time.




where does ^^^^ say that?


David Jenkins - 30/8/07 at 03:29 PM

Even the cold facts are astonishing...

Wikipedia


skydivepaul - 30/8/07 at 03:39 PM

if you ever get the chance to watch the top fuellers at santa pod - (next weekend) - they are absolutley awesome.

well worth a trip down there
linky

I went to see them at Easter this year and this was my favourite

Competitor: Urs Erbacher
Class & Race Number: TF 111
Home Town / Country: Switzerland
Vehicle: Dragster
Vehicle Name: Midland
Engine Size: 498ci



[Edited on 30/8/07 by skydivepaul]


ditchlewis - 30/8/07 at 04:06 PM



just a bit to fast for me. i'd loose the little hair i have left very fast

ditch


pajsh - 30/8/07 at 04:16 PM

Pro Mods are my favourite although the Top Fuel bikes and Twins are impressive too.

Any one fancy lying on top of a supercharged V twin producing over 1000 BHP and then doing a 1/4 mile wheelie in around 6.5 seconds with a termial speed in the mid 200's.

Mad as a box of frogs!


[img][/img]


russbost - 30/8/07 at 04:51 PM

It's just a "Death Wish" thing really isn't it.


RazMan - 30/8/07 at 05:38 PM

Guys, please remember your pets before you put your foot down.... Rescued attachment Fast acceleration.jpg
Rescued attachment Fast acceleration.jpg


flak monkey - 30/8/07 at 05:45 PM

I am sure I posted that collection of gems a year or 2 ago. Its been around a long time.

Heres a pic i took at the finals last year




The top fuellers are amazing bits of machinery. Really the pinnacle of internal combustion engines. 8000bhp

I know a gent who ran a 2000bhp Ford Pop in the 90's. A complete nutter.


Confused but excited. - 30/8/07 at 06:20 PM

"Including the burnout, the engine must only survive 900 revolutions under load."

Not much use as a donor then.


iank - 30/8/07 at 06:52 PM

quote:
Originally posted by Confused but excited.
"Including the burnout, the engine must only survive 900 revolutions under load."

Not much use as a donor then.


Think you'd need a McSorley +28 to fit one anyway

I didn't realise the amount of downforce the open exhausts generate (on the wikipedia entry)

Top fuel is a weird mix of high technology and ancient design. 2 valves per cylinder pushrod engine, but using exotic materials all over the place and a billet CNC machined block+heads.


Simon - 30/8/07 at 08:43 PM

I agree with skydivepaul - I went about 20 years ago and have been saying I'll go back ever since.

Next year maybe. Stuff on for next couple of weekends.
ATB

Just a thought - how do you time and fuel an engine in about 6 revs. After all, you don't want to use to many of your 900


Simon

[Edited on 30/8/07 by Simon]

[Edited on 30/8/07 by Simon]


gazza285 - 30/8/07 at 09:18 PM

Me father rebuilt the fastest Triumph drag bike made for the National Motorcycle Museum after the owner was killed riding it. It was all going well until we found half a plate of false teeth embedded in the fairing. The cat enjoyed playing with them though.


akrallysport - 30/8/07 at 10:23 PM

The definition of accelertion actually a = F/m.


procomp - 31/8/07 at 07:15 AM

Hi Had a good friend who was once involved with drag racing as well as many other classes of motorsport.

And built what was once the world's fastest road registered road car.
I think after it was decided to build a better one it was sold to some guy in london who had no wish to use it as a dragster. Just as a road car.

Tom Laffey's capri dragster. Once recorded as the world fastest road legal car.
Tom Laffey's capri dragster. Once recorded as the world fastest road legal car.
[/img]

cheers matt