Acceleration

[Cobra #3170]

This may have been posted previously, if not very impressive


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 of a second for all 6,000+ horsepower of an NHRA Top Fuel dragster engine to reach the rear wheels.

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

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 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 4.428 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 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.

[RICK LAKE]

Cobra#3170 I would be more interested in the silver bullet against the ZR1, or twim turbo ZO6. I see top end as the only place you may get caught. Have to remember that you only have about 6-8 psi of boost with a stock bottom end LS block. Rods would give up first in the ZO6. Rick L.

[Chaplain]

I have taken my sons to NHRA Nationals and they were impressed. I took my teenage daughter last week to the TOYO Nationals Qualifications at Maple Grove Raceway here in PA. She was in shock for the top fuel runs. Couldn't believe the concussion felt from the runs. I've seen hundreds of runs and I'm still in awe as I was when I first experianced top fuel. Incredible machines whose technology we have all benefitted from.

[ERA Chas]

3170,
Thanks for great fun facts. Do you know the original source for the data? I don't think Johnson, Prock or Coil chat about this stuff.

[Cobra #3170]

Originally Posted by ERA Chas

3170,
Thanks for great fun facts. Do you know the original source for the data? I don't think Johnson, Prock or Coil chat about this stuff.

ERA Chas,

No, I don't know the original source, I got it from a good friend who is an engine builder but not Top Fuel engines. I had the opportunity to talk with Austin Coil about these engines several years ago and he said that the ignitions were so powerful that they could fire in liquid Nitro methane, he also said that they free rev at 50,000 RPM per second. They were taking enormous amounts of computer data and could monitor the firing voltage on each plug on every firing revolution through out the run along with all the other standard stuff like wheel speed, engine rpm, manifold pressure, oil pressure, fuel pressure, fuel flow, acceleration rates, chassis stress etc etc. They then use the data to get the right tune. It was very impressive, and indicated the depth of technical expertise in Drag Racing. They have to use all this data to adjust the air timers used to control the clutch and engine parameters which is very difficult since air timers are less than precise.

[rustyBob]

thats cool..........i think i will build a new motor for my Cobra now.......

[BDR298]

We sponsor Tim Wilkersons Fuel Funny Car. I have seen that data before , it has been around a long time. Pretty accurate.
We burn 14 gallons in Nitro per 1000 ft pass, price varies , right now around $33 a gallon. The engines with the 2009 rules are making 8000 hp. They only run 1000 ft in the fuel cars now because they were running out of shutdown space at some tracks and they are trying to slow them down. They still do 290mph to 300mph.
We do collect about 22 sensor in the car to use between run, It is use to set clutch, timimg things like that. The concisson felt is incredible. It is an experience to be in the shop and see multiple engines being built. They are works of art. We took 13 engines on the west coast swing of Denver Seattle and Sonoma and still sent some back to the machine shop for rebuild. In 13 years of prfessional racing Tim has only run 1 pass without rebuilding the engine. We have 50 to 90 minutes to completely rebuld the car between rounds. This year we run 5 cluthes in the clutch packs and they pretty much fall out after each run.

[ERA Chas]

Thanks 3170 and 298;

Been going to see fuel cars since age 16 and that was right after dirt was invented.

Had good chats with Dyno Don (Eliminator SOHC car), Dale Armstrong, Blaine Johnson and Eddie Thrill Hill (first in the 4's!)

Am suspicious of how 50,00 rpm/second is measured...