You got good acclereration?
You got good acclereration?
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dbv8

Original Poster:

8,676 posts

249 months

Wednesday 18th January 2012
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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 (0.15) of a second for all 6,000+ horsepower (some believe 8,000 HP is more realistic - there are no dynamometers capable of measuring) 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. (Oxy-acetylene on "cut" is 6,300) 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 one 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 4.428 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 instant. 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!

Grey Ghost

4,610 posts

249 months

Wednesday 18th January 2012
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yikes

neal1980

2,584 posts

268 months

Wednesday 18th January 2012
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cut and paste....or you not doing much work today hehe

This will be the story of me and you when I blast past biglaugh

dbv8

Original Poster:

8,676 posts

249 months

Wednesday 18th January 2012
quotequote all
neal1980 said:
cut and paste....or you not doing much work today hehe

This will be the story of me and you when I blast past biglaugh
Yeah then the marshals wont be happy having to clean up all that schrapnel from your turbos. hehe

Sevenman

764 posts

221 months

Wednesday 18th January 2012
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Not to be pedantic, but..

dbv8 said:
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.
Under full throttle a 747 produces far more power than a dragster... I am unsure of its fuel efficiency, but modern jet engines are quite efficient (and dragsters are not).

From this link, it indicates that a 747 at high-altitude cruise (1/4 power) is doing work equivalent to 87,000 bhp.

Extrapolating that for the latest 747 engines, and full power then it is about 401,000 bhp.

Impressive as dragsters are, it isn't an ideal comparison.


For the flying start, if the Corvette is doing 200 mph, it will take 4.5 seconds to run the 1/4. Given the world record 1/4 mile is 4.428 seconds, it seems likely that, in most cases, the Corvette will win. Impressive as dragsters are, a speed of 180 mph would have been a safer bet.

Edited by Sevenman on Wednesday 18th January 14:32

dbv8

Original Poster:

8,676 posts

249 months

Wednesday 18th January 2012
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Sevenman said:
Not to be pedantic,
laugh

900T-R

20,406 posts

286 months

Wednesday 18th January 2012
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Could you try and insert some paragraph endings in there? My head hurts. headache

Yours,
Capitain Slow. smile

Sevenman

764 posts

221 months

Wednesday 18th January 2012
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dbv8 said:
laugh
Well, maybe a little, but it's what I do..

nelly1

5,665 posts

260 months

Wednesday 18th January 2012
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Sevenman said:
Not to be pedantic, but...

For the flying start, if the Corvette is doing 200 mph, it will take 4.5 seconds to run the 1/4. Given the world record 1/4 mile is 4.428 seconds, it seems likely that, in most cases, the Corvette will win. Impressive as dragsters are, a speed of 180 mph would have been a safer bet.
nono

3.752s @ 325mph...

eek

dbv8

Original Poster:

8,676 posts

249 months

Wednesday 18th January 2012
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It would be excellent to see such a race in practice.
I guess Top gear could do one on a smaller scale.
Some hot hatch at 120 constant versus Red Victor 3 scratchchin

Sevenman

764 posts

221 months

Wednesday 18th January 2012
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nelly1 said:
I was only quoting the original post for 4.4s - I can only be as good a pedant as the information I have to work with smile That is very quick.
Wikipedia is down today, and without that, I can't function.

There could be some interesting smaller-scale races, from dull cars vs sports cars to faster cars vs. Red Victor.

dbv8

Original Poster:

8,676 posts

249 months

Wednesday 18th January 2012
quotequote all
I ran a bracket race at York against a VW beetle (standard).
As he was dialled in at 21 seconds and i at 13 it meant i had to sit for 8 seconds after he set off before i got my green light. That (apart from some love making many moons ago) was the longest 8 seconds of my life.
I was at nearly double his speed as we crossed the finish line a 0.1 second apart. I won smile

I am going to enter 'Pro-ET' at York this year and the tables will be turned. I will be trying to run 11.9 @ 120 ish with some cars catching me @ 170+ in 8 seconds.

Slow M

2,901 posts

235 months

Thursday 19th January 2012
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Another superlative for dragsters is in the area of piston velocities, exceeding F1, and NASCAR on the order of 15%-20%.

dvs_dave

9,040 posts

254 months

Thursday 19th January 2012
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nelly1 said:
Since about '08 Top fuelers don't run a full 1/4 anymore but run 1000 ft instead, hence the seemingly much faster times of late.

Basically down to a nasty accident unfortunately involving the death of a driver, and the NHRA imposing knee jerk rule changes as a result. It'll be back to a full 1/4 soon once they've decided on how to safely handle tracks with shorter shutdown distances.

Chilliman

12,421 posts

190 months

Thursday 19th January 2012
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The world will be turned on its head when me and beastie hit the strips this year smokin

haircutmike

22,460 posts

233 months

Thursday 19th January 2012
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Chilliman said:
The world will be turned on its head when me and beastie hit the strips this year smokin
Richard, WAKE UP! It was all a dream.................

Sevenman

764 posts

221 months

Thursday 19th January 2012
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dvs_dave said:
Since about '08 Top fuelers don't run a full 1/4 anymore but run 1000 ft instead, hence the seemingly much faster times of late.
And the balance tips back to the Corvette, with a 3.41s 1000ft time wink

I'll admit, the 200mph starting advantage is fairly generous...

It would be interesting to see the acceleration vs. time and speed vs. time plots for a Top Fuel Dragster. Given the terminal speeds haven't changed that much given the reduction in distance, it must be at close to full speed after 3 seconds, with rapidly diminishing acceleration after 2. Maybe.

Chilliman

12,421 posts

190 months

Thursday 19th January 2012
quotequote all
haircutmike said:
Chilliman said:
The world will be turned on its head when me and beastie hit the strips this year smokin
Richard, WAKE UP! It was all a dream.................
Bugger getmecoat

dbv8

Original Poster:

8,676 posts

249 months

Thursday 19th January 2012
quotequote all
Sevenman said:
And the balance tips back to the Corvette, with a 3.41s 1000ft time wink

I'll admit, the 200mph starting advantage is fairly generous...

It would be interesting to see the acceleration vs. time and speed vs. time plots for a Top Fuel Dragster. Given the terminal speeds haven't changed that much given the reduction in distance, it must be at close to full speed after 3 seconds, with rapidly diminishing acceleration after 2. Maybe.
yes
I think they run 2 gears. Gearing is also greatly affected by tyre growth.

Some more interesting stuff here.... http://www.theaccelerationarchive.co.uk/features/a...

A top fuel can hit 100 in around 0.7 seconds in less than 60 feet says a lot i think.

Gazzab

21,633 posts

311 months

Thursday 19th January 2012
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I'll race one (around a track).