top fuel drag racing

[AlexF]

I've just got one of those "did you know emails", but is this all true?!?!

* One Top Fuel dragster 500 cubic inch (that's 8.2 litres in new money) Hemi
engine makes more horsepower than the first 4 rows at the Daytona 500.

* Under full throttle, a dragster engine consumes 11/2 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 supercharger.

* With 3000 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 1.7:1 air/fuel mixture for nitromethane the
flame front temperature measures 7050 degrees F.

* 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 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 1/2
way, the engine is dieseling from compression plus the glow of
exhaust valves at 1400 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
at 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 9500rpm.

* The Bottom Line; Assuming all the equipment is paid off, the crew
worked for free, and for once NOTHING BLOWS UP, each run costs an
estimated US $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 1320 foot
long race course.

That, folks, is acceleration.

[Andrew Kitson]

Yes all totally true. If you have not seen them, they are astounding when the lights go green. The whole ground shakes and you 'feel' the noise as your whole body vibrates. If you stand by the finish line, it is difficult to focus on them. Not only are they going 300 mph + but the shock of the noise causes your eyeballs to vibrate! Ah the lovely smell of Nitro....can't wait to head to Santa Pod this coming summer.
The only downer is the fact that we have to cope with the unpredictable English weather - spent many hours waiting around at the Pod on a 'rain down' or even an 'oil down' as the aftermath of an expensive engine detonation is cleared up. Make sure you go on a guaranteed dry day.

Pity we do not have more of these cars. Usually there are 5 or 6 top fuellers at a meeting with many other lesser classes too (an entry of around 200 competitors, cars and bikes is the norm) There are normally 3 runs per top fueller per day. Will have to get to the States someday where there are 20+ cars.
All in all, an awesome spectacle!
www.santapod.com

[KC]

I have not seen an NHRA Top Fuel rail run in person, I have however, stood within reaching distance of many Top Fuel drag boats. With any kind of motor racing, being their in person makes all the difference in the world. When a top fuel engine is started it runs on straight alcohol until warmed up. The race engine at idle is very loud and has the characteristic supercharger lope sound. Very distinctive. At this point it is making between 1800 and 2200 horsepower. When the fuel is switched over to 90% nitromethane it will literally double in sound and it honestly sounds like a giant continuous explosion. The first time you hear one up close it will invoke the flee instinct in you. The engine does not lope at idle anymore, it just shakes and roars. A typical Top Fuel engine is louder than a 747 jet at takeoff. It is also producing between 6000 and 8000 horsepower.

During a single 5 second pass the following items are consumed. The spark plug electrodes will be consumed by the combustion including portions of the threaded body. Engine oil is contaminated by large quantites of alcohol being forced past the piston rings by the supercharger making it look like gray or tan goop. The long teflon seals on the supercharger vanes are destroyed by the insane backpressure against them and must be replaced.

If a spark plug fails to fire, the resulting solid mass of air and fuel cannot be adequately compressed and it will either blow out the burst panels on the supercharger, forcibly eject the offending spark plug to vent the pressure, or fold up the con rod. Since the compression level is so high, it is possible for the engine to backfire and actually try to run backwards causing all kinds of damage.

At a typical NHRA event, the team has 70 minutes between rounds to make the car ready for its next round if it won. One or two guys lie down under the car and remove the oil pan which is held on with safety catches and inspects the lower end for damage. They will replace the main engine bearings and rod bearings at this time. One guy will remove the supercharger and injector hat for rebuild. A rebuilt unit has already been made ready. The fuel system is setup on the rebuilt unit using the original hat and bypass valves. One guy on each side removes the heads and either replaces them with rebuilt units or will quickly replace all the valve springs and any burned or bent valves. Lean condition erosion is looked for and parts are replaced as needed. Another guy checks the top of the pistons for meltdown and checks to make sure the piston rings are still intact. Its not uncommon to find the top compression rings completely shattered. Rings are replaced as needed. As the engine is neing reassembled, another guy pulls the clutch from the back of the motor and replaces it with a new or rebuilt unit. All initial adjustments are made at this time based on what the crew chief thinks he can get away with. The clutch absorbs the initial burst of power so that the tires have a chance to keep up with the engine. All telemetry data is downloaded from the onboard computer. Engine temp, exhaust cylinder temps are checked to make sure the injetor is working correctly and no one cylinder is acting wrong. The car is started and the clutch is broken in and then they report for their next round. All done in 70 minutes or less.

[shiny side up!]

Even reading all of these descriptions, you cannot really understand a Top-Fuel dragster until you see one run live... it is a harrowing experience if you aren't prepared!!!

[tangoed sparky]

A fuelly will rattle you internal organs like a F1 car rattles your ear drums they are awesome. You need to see them at Santa Pod to understand.

[StephenRae]

The lengths drag racers go to are truely awesome the power outputs are amazing.
How do the tractor pullers link all those engines together? if you've got 56 cylinders how would you know if one is misfiring, and how could you find it?

[imull]

knock sensors stephen



i see that one of the fastest eropean top fuel bloke has been told to quit. He broke his sternum (?) when pulling the parachut. His body shot forward into the slightly loose harness...

[avsfan733]

imull, a similar thing happened to a US top FUeler, I believe it was detatched retinas though. Its really incredible to think about all that happens in those 4.5 or so seconds.

[KC]

Kenny Bernstein had his eyes surgically worked on 3 times during his career to correct distended retinas. The immense g-forces encountered when the chutes hit at 300+ mph puts too much strain on the human body. HANS devices are common among the top drivers and the NHRA may have made them mandatory to help drivers withstand the braking forces that are about the same as a crash.

[Bob Riebe]

Big Daddy Don Garlits, Mr. Top Feul, had to quit because of detached retinas.
He came back for a bit last year to be able to the 4 second range to his career.
Art Arfons gave up speed record racing because his eye balls bounced to much due to lack of practice, and he did not want to have to go through the ritual to once again adapt.
Bob

[dretceterini]

* With 3000 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.>

Part of the reason timing is critical and pistons often go BOOM!

[avsfan733]

Somebody a while back developed a turbo engine as opposed to a supercharged one...it was banned but before it was it developed and estimated (as are all figures at this level) 12000 BHP, no dyno could measure it or any engine run nowadays, the thing also ate driveline components as nothing could be designed then to hold the power

[noodles]

I recall reading somewhere that these engines run Ignition Adavnce of the order of 70 degrees BTDC, due to the extremely slow burn rate of 90% NitroMethane mixture. I believe the spark duration is also quite long as well.

Nitromethane is a very low on the flammability scale, less than say kerosene. For example, if 100 is the bottom limit and 0 the top limit on this scale, nitromethane rates around 98. Compare that to pump petrol or gasoline which rates around 30.

[Ralph Nader]

Presumably they only do about 300 actual revolutions between rebuilds!

[KC]

Noodles is right. The burn rate across the combustion chamber is so slow that the spark plug fires very early otherwise the combustion would occur while the cylinder is already down. At high rpm the engine will begin to compression combust and will destroy itself if allowed to continue much longer than about 8 seconds. Thats why the spark plugs get destroyed on every pass.

[StephenRae]

I am staggered by these power outputs. Have they been achieved over the years purely by (very expensive) trial and error and is there more to come?

[Andrew Kitson]

Perhaps we should consider a drag racing forum? We have forums for other non-car racing classes such as karts, rallying etc. There is a large following for the sport right across Europe, also Australia and it is massive in the USA of course. All of the drag race teams have websites.
What do you think Craig?

[GolddustMini]

the aim is to eek as much power as possible for only a few seconds under the load, its then a case of pull the engine to bits, replace the worn components (of which there are many!) and stick it all back together in time for the next run!

[listernoble]

A couple of years ago I went with some hillclimb friends to the European Finals at Santa Pod.
We thought maybe it would be a bit boring and we would only stay a couple of hours.
We could not have been more wrong!
Fantastic machinery,6000bhp and awesome noise, you can actually feel your body move as they go past.A jet propelled car was also there running on full afterburn.
Very friendly crowd and incredibly friendly drivers & crew etc. they were interested in our side of the sport and took time to talk to us.
Engines totally stripped betwwen runs and you can walk among them and watch while they are doing it.
Probably one of the best motorsport experiences I have had.
Lister

[avsfan733]

has anyone mentioned that they don't run coolant yet?

[GolddustMini]

i must attend a drag meeting (should i be ironic and go in drag???) this year

[dretceterini]

Computerized traction control and readouts have knocked times down almost half a second and added 20 mph to trap sppeds in the last few years. I think tire technology will knock ETs down to 4 seconds within 5 more years, with trap speeds around 350 mph.

[KC]

The NHRA and IHRa have moved to ban MSD 7AL Ignition control modules that can be programmed to act as traction control for the sportsman classes and they plan on taking steps to keep the fuel classes under control. About half of the tracks in NA cannot support a 350 mph machine. They do not have enough shut down area and have no way to extend their tracks. I expect the NHRA to reduce nitro percentage for fuel again and mandate a lower final drive ratio again shortly.

[StephenRae]

I read somewhere (no doubt by someone trying to denegrate the sport) that a computer could do a better job of driving the car. I can't believe it, but I do wonder how you steer,or do you just point it and hope. The front wheels are hardly on the ground so the torque must feed evenly to the driven wheels....awesome stuff!

[avsfan733]

Originally posted by dretceterini
Computerized traction control and readouts have knocked times down almost half a second and added 20 mph to trap sppeds in the last few years. I think tire technology will knock ETs down to 4 seconds within 5 more years, with trap speeds around 350 mph.

they don't run traction control...or anything computerized, the data aq is for data logging only can't change fuel air or anything. traction is controlled by a clutch pack with mechanical timers and air switches letting a certain amount of power reach the tires which slowly increases during a run