Top Fuel facts

[Ian]

- The motor only turns between 600 to 700 RPM's during the quarter mile

- They burn a mixture of 85% nitromethane & 15% alcohol

- 7-8 gallons of fuel is consumed per run

- 0-100 mph in 0.75 seconds

- 0-300 mph in 3.00 seconds

- A top fuel dragster's 500 cu.in. Hemi makes more horsepower than the nine cars in the first three rows at the Indy 500

- Under full throttle, the motor consumes 1.5 gallons of nitromethane per second, the same as a fully loaded 747, but with 4x the energy volume.

- The supercharger takes more horsepower to drive than a stock production Hemi makes.

- With over 3000 CFM of air being rammed in by the overdriven supercharger, the nitromethane is compressed into nearly solid form before ignition. The eight cylinders run on the verge of hydraulic lock.

- Dual magnetos apply 44 amps to the spark plugs that fire each cylinder, the equivalent of an arc welder.

- At stoichiometric (exact) 1.7:1 air/fuel mixture, the flame front of nitromethane measures a scorching 7,050*F.

- Nitromethane burns yellow. The spectacular white flame seen above the exhaust stacks at night is raw burning hydrogen, disassociated from atmospheric water vapor by the searing exhaust gasses.

- Spark plug electrodes are totally consumed during each pass. About halfway through the 1/4-mile run, the engine is dieseling from the extreme compression, plus the glow of exhause valves at 1400*F. the engine can only be shut down by cutting off fuel flow.

- If spark momentarily fails early in a run, the unburned nitromethane that builds up in the affected cylinder(s) can explode, blowing the heads to pieces and splitting the block in half.

- Top fuelers twist the crank (torsionally) so far (20* in the big end of the track), that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.

- To exceed 325 mph in 4.5 seconds, the driver must accelerate at an average of more than 4G's. In reaching 200 mph well before half track, the forces are closer to 8G's.

- Drivers shut down before the finish line, or even dual parachutes wont stop the car.

- If the car and equipment are paid off and the crew worked for free, each run still costs more than $1,000 per second

- NHRA top fuel dragsters exceed 300 mph before you have read this sentence.

[Rob WS6]

Damn where did you dig that up? Interesting none the less.

[79CamaroDiva]

Only one that isn't true as far as i know is the drivers shutting down before the finish line. They pull the chute before the finishline, and prepare to shut down prior to it, but if they shut down before, how the hell could they win a race? Maybe the pullt he fuel shut off early, but that wouldn't make sense to lean out the engine fully at a full load. There'd be more damage each run then there already is.


BTW..

rrrrrrrrepost

[Ian]

I got all the facts out of Tech magazine. its the magazine that Snap-On puts out. You can't get it unless you're a tech though, thats how I got mine.

And as far as it not being true, I just typed what I read in the magazine....word for word.

[Tru2Chevy]

Originally Posted by Ian

I got all the facts out of Tech magazine. its the magazine that Snap-On puts out. You can't get it unless you're a tech though, thats how I got mine.

And as far as it not being true, I just typed what I read in the magazine....word for word.

I knew I had read that before somewhere....

I agree with Melissa though (she would know), they yank chutes before they cross the line, but there's no way they would shut them off then.

- Justin

[12secondv6]

Those are facts about driving a neon!

[badzracing]

Those are facts about driving a neon......of a cliff in a fiery display of destruction

[jims69camaro]

Originally Posted by Ian

And as far as it not being true, I just typed what I read in the magazine....word for word.

you saw it in a magazine? then it MUST be true!!!11!

j/k the list is still damn interesting.

[79CamaroDiva]

Originally Posted by Tru2Chevy

I knew I had read that before somewhere....

I agree with Melissa though (she would know), they yank chutes before they cross the line, but there's no way they would shut them off then.

- Justin

dont be so quick to agree with me, I know about as much about how to run a top fueler as how to work on a rotory. I just dont see how or why they would kill it prior to the finish line. Makes no sense, and if it doesn't make sense, it probably isnt true. Further research might need to be made

[Injuneer]

Originally Posted by Ian

- The motor only turns between 600 to 700 RPM's during the quarter mile

Just to nit-pick..... the motor only turns between 600 to 700 revolutions during the quarter mile.

[foff667]

Originally Posted by Injuneer

Just to nit-pick..... the motor only turns between 600 to 700 revolutions during the quarter mile.

thats not nitpicking i was going to question that actually...didnt make sense they only spin it to where normal cars idle but that explains it much better considering lets say it takes 4.5 seconds in the 1/4 mile...that would mean ~12000rpms

[Pampered-Z]

The reasoning for shutting down early is because of the time it takes to actually shutdown the motor ( only way is to kill the fuel flow - noted elsewhere) )and distance a topfueler is traveling. Remember the motor is igniting the fuel by the compression and heat, much like a diesel engine, so it takes time before the fuel lines empty and the engine to shutdown. Think about it, if you pull the fuse to your fuel pump the car will run for some time until the pressure drops, it is not like turning off the ignition.

And remember at 300+ MPH your covering allot of ground VERY quickly. The engine is turning at 9,000+ RPMs and the clutch is locked in so you have an engine you can't turn off that is direct drive to the tires. Momentum is going to keep the engine turning over too.

So, if the driver shuts off the fuel and pops the chutes at say 1,100' (the footage is just my guess for this example, I don't think they are trying to say this happens at 1/2 track, just that the driver does wait until he crosses the finish line before he starts the shutdown).

By the time the chutes deploy and the engine stops firing they have crossed the finish line. They are still 'running it out the back door'.

Doesn't matter if they hurt parts, they expect to hurt it and besides, they're tearing it completely down between rounds anyway!

[BigAls87Z28]

Originally Posted by Injuneer

Just to nit-pick..... the motor only turns between 600 to 700 revolutions during the quarter mile.

Damn...you beat me to it.

[SteveR]

They used to run 90% nitro until this past season. The reason was because of two crashes last year, one was Tony Schumacher in St. Louis. The only place they still run where they lighten the restrictions is Denver, where they can still run 90% and as much overdrive on the supercharger that they want. I hear that they will be lowering the rev limit on the Top Fuel cars next year too.