Thread: drag racing facts

Tweet

This was forwarded to me through the monte carlo list.



Top Fuel Dragster Facts...

ACCELERATION PUT INTO PERSPECTIVE
* One Top Fuel dragster 500 cubic-inch Hemi engine makes more horsepower
(8,000 HP) than the first 4 rows at the Daytona 500.

* Under full throttle, a dragster engine consumes 11.2 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 merely
drive the dragster's 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
nitro methane the flame front temperature measures 7050 degrees 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 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.

* Dragsters reach over 300 MPH before you have completed reading this
sentence.

* In order to exceed 300 MPH in 4.5 seconds,
dragsters must accelerate an average of over 4 G's. In order to reach
200 MPH well before half-track, the launch acce leration approaches 8
G's.

* 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 9500 RPM.

* THE BOTTOM LINE: Assuming all the equipment is paid off, the crew
worked for free, & for once, NOTHING BLOWS UP, each
run costs an estimated $1,000 per second.
0 to 100 MPH in .8 seconds (the first 60 feet of the run) 0 to 200 MPH
in 2.2 seconds (the first 350 feet of the run) 6 g-forces at the
starting line (nothing accelerates faster on land)
6 negative g-forces upon deployment of twin chutes at 300 MPH

An NHRA Top Fuel Dragster accelerates quicker than any other land
vehicle on earth . . quicker than a jet fighter plane . . . quicker than
the space shuttle.

The current Top Fuel dragster elapsed time record is 4.420 seconds for
the quarter-mile (2004, Doug Kalitta). The top speed record is 337.58
MPH as measured over the last 66'
of the run (2005, Tony Schumacher).

Putting this all 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 &
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 & pass the dragster at an
honest 200 MPH. The 'tree' goes green for both of you at that moment.
The dragster launches & starts after you. You keep your foot down hard,
but you hear an incredibly brutal whine that sears your eardrums &
within 3 seconds the dragster catches & 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 & not only cau ght, but nearly blasted you off the
road when he passed you within a mere 1320 foot long race!

THATS ACCELERATION!!!!

Theory only, a calculator was used in theory only. The nomenclacture used is from a college prof who wanted to show off for his students. Sorry, I have my old readouts from the computer and spent so many hours tearing them down, no way, no how is that accurate. I've seen it posted at least a dozen times in the past five years and I used to laugh, but now it's not as funny as it used to be. Sorry, it's time to open up and say something about the "theory" of the run.

sorry i did not know

Originally Posted by nitrowarrior

Theory only, a calculator was used in theory only. The nomenclacture used is from a college prof who wanted to show off for his students. Sorry, I have my old readouts from the computer and spent so many hours tearing them down, no way, no how is that accurate. I've seen it posted at least a dozen times in the past five years and I used to laugh, but now it's not as funny as it used to be. Sorry, it's time to open up and say something about the "theory" of the run.

please tell us what part is theory, i can clearly see the fuel consumpsion at 11.2 gallons per second wrong. its more like 11.2 to 13 galllons per pass. and also don garlits quoted a 7000 dolars per pass, but his figure was based on purchasing the equipment, hauler, car, parts and crew pay spread out over the entire year.

sorry i now am reading what you posted, at the same moment i posted mine, i clearly agree 100% with what you were getting at!

No need to be sorry, it's just a lot of misinformation gets out on the web and it sounds either phenomenal or simple. I am getting crotchety in my old age and get a wee bit tired of the mis-nomers about the sport I spent way too much time to have it belittled. I mean no offense to you or those whom wish to enjoy it. I wish that the truth come out and be presented properly. That's all, at least you're digging nto the research part of it. I wish more would be as diligent as you.

If you have it, would you share it, the truth that is? BTW, Schumacher owns both ends of the record, he set it last year at the finals to win the championship.

Tony has some great support and wonderful backing. Nobody here disputes that. All the participants are family and not in the ceremonial way. It truly is a "FAMILY". Data sheets are something that would take a week for me to post. I have to ask Denny for help in the little things to get them righ tto display here. Let me give a bit a info on a 540 RPM run. Driveline speed alone will achieve that in the first 1.1 to 1.2 seconds to try to get the tires to come up and stop the "shake" so they transition into n the stretch for full bite. Plugs don't react like the info states. Think about pulling them for the co-crew chief to read before the heads even come off. If they were that wasted, the heads would be replaced as new every pass. Hhhmmm, It's just a calculator from the soidelines that comes up with the "stats" on the run. 7000 degrees plus on fuel burn? Whether in the chamber or head, what material besides the space shuttle could withstand that? Can you spell disaster on the line? It's a lot of fun and speculation to toy with to entertain the brain. But, when you actually use the data from each run, it becomes a different ball game each pass. Wrinkles and grey hair are a common side effect and it's an addiction to be wary of.

On average, we always burned about 14 gallons per pass. Most of that was fire-up, burnout, and staging. per run? I gasp to factor the cost of operation of course, but if you didn't factor in the outside stuff and just the car moving, lean side would be 4000 a run (restrictively). I like peoples interest in how it actually works. I just don't like everybody feeling that it's an easy task to perform. Even the crew stands there and hold their breath hoping against hope to continue on. I feel for Don Schumacher, Don Prudohme and J Force, Connie Kalitta etc....what an ulcer causing career it is.

It was much simplerer when we only used one parachute and one fuel pump

Jerry Clayton
Keeling & Clayton California Charger

Originally Posted by jerry clayton

It was much simplerer when we only used one parachute and one fuel pump

Jerry Clayton
Keeling & Clayton California Charger

And Top Fuel dragsters were beautiful as well as fast!

The Keeling and Clayton cars were always some of the most stunning race cars ever.

Mick

I really think it's great we've got folks on here that do know the facts of top fuel racing and can put it in perspective. What can I say, CHR rocks!!!

On revs per pass, 540 doesn't seem too outlandish... back of the envelope ("theoretical"?), if you're at 9500rpm through the whole run (not likely?), the motor turns over 9500/60*4=633 times in four seconds... am I missing something? Anyways, thanks nitro for your insights

-Chris

they were some of the beaut's the sport had thats for dang sure. and the new re-creation is definatley stunning and beautiful. you can get info on it at www.nitrogeezers.com hope i dont get deleted for that !

AH ha....Tire and clutch slippage. You forgot to factor that part. I'ts a major part of why a crew chief gets his salary. Management of the clutches to slip enough to roll out and start to get a bite creates a revolution count higher than the theory indicates. Tires never do get a perfect bite throughout the run. Too much slippage, it takes the skins right off quickly. tires only good for a few passes. Too much bite, you either suffer "shake" or internally break the casing down to a point that no more than two runs per pair. The Engines turn on average of 7200 RPM. Fluctuating slighty(if it's a good run) a few hundred RPM. So let's say the geometry that the calculator was count for count. The car could have gears for wheels, the track would have a rack gear laid out to accomodate the wheel gears. Then according to the circumference of the Gear/Wheel it would only take so many revolutions to complete the run according to the gear ratio of the axle. Not everything is on the track as it is on paper. Fun stuff to ponder to figure how to get your car down the track.

Originally Posted by nitrowarrior

AH ha....Tire and clutch slippage. You forgot to factor that part. I'ts a major part of why a crew chief gets his salary. Management of the clutches to slip enough to roll out and start to get a bite creates a revolution count higher than the theory indicates. Tires never do get a perfect bite throughout the run. Too much slippage, it takes the skins right off quickly. tires only good for a few passes. Too much bite, you either suffer "shake" or internally break the casing down to a point that no more than two runs per pair. The Engines turn on average of 7200 RPM. Fluctuating slighty(if it's a good run) a few hundred RPM. So let's say the geometry that the calculator was count for count. The car could have gears for wheels, the track would have a rack gear laid out to accomodate the wheel gears. Then according to the circumference of the Gear/Wheel it would only take so many revolutions to complete the run according to the gear ratio of the axle. Not everything is on the track as it is on paper. Fun stuff to ponder to figure how to get your car down the track.

I understand there are drivetrain losses but the simple math of how engine rpm and the length of time from start to finish (not counting burnout and staging) add up really gives you very few revolutions down the quarter mile... for instance:

Lets say you average 7200 revolutions per minute 7200 / 60 (seconds per minute) makes 120 revolutions per second...

Now if it takes 5 seconds for 1/4 mile ET (a slow TFD), you end up with 120 *5 = 600 revolutions of the engine from starting line to finish line...

Same illustration with a 12 second bracket car:

Maybe 5000rpm average = 83.33 rps * 12seconds = 1000 revolutions from start to finish.

In the 12 second car, if there were no drivetrain losses, it would only take something around 850 revolutions to cover the distance (30" tire, 4.56:1 gear, discounting gear reduction in the transmission) but the math above only covers the engine rpm and the amount of time the run takes... no other drivetrain characteristics matter.

It is fun to figure this stuff out even if the particulars aren't particularly important


Edit: sorry... posted this without reading the rest of the thread... anyhow, I think Jerry and I are trying to say the same thing.