how much nitro does a top fuel car use?

FOURTOGO said:
What about 16gal's per run from start to finish
Click to expand...

16 gallons, and the majority of it is wasted fuel. Roughly 70%, is used to cool the motor and control detonation.

Not sure if it is proper to use the word detonation when talking about Top Fuel, lol.
 
Acceleration explained.

* One Top Fuel dragster outfitted with a 500
cubic-inch replica Dodge (actually Keith Black,
etc) Hemi engine makes more horsepower (8,000
HP) than the first 4 rows at NASCAR's Daytona
500.

* Under full throttle, a dragster engine will
consume 11.2 gallons of nitro methane per
second; a fully loaded Boeing 747 consumes jet
fuel at the same rate but 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 lockup at full throttle.

* At the stoichio metric 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. Which is typically the output of an
electric arc welder in each cylinder.

* Spark plug electrodes are totally consumed
during a pass. After 1/2 way thru the run, the
engine is 'dieseling' from compression and the
glow of the 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 enough
sufficient force to blow the 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, a
dragster must accelerate an average of over 4
G's. In order to reach 200 MPH well before
reaching half-track, at launch the acceleration
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 for, the pit crew is working for free,
& NOTHING BLOWS UP, each run will cost an
estimated $1,000 per second.

0 to 100 MPH in .8 seconds (the first 60 feet
of t he 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....or snapping your
fingers !!

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).

Let's now put this all into perspective:

Imagine this...........You are driving a new
$140,000 Lingenfelter twin-turbo powered
Corvette Z-06. Over a mile up the road, a Top
Fuel dragster is staged & ready to 'launch'
down a quarter-mile s trip as you pass. You
have the advantage of a flying start. You run
the 'Vette hard, on 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 exact
moment.

The dragster departs & starts after you. You
keep your foot buried hard to the floor, and
suddenly you hear an incredibly brutally
screaming whine that seares and pummels your
eardrums & within a mere 3 seconds the dragster
effortlessly 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.....and it not only caught,
but nearly blasted you off the planet when he
passed you within a mere 1320 foot long race
!!!!

That, my friends.....is acceleration
 
And rebuilding the engine after every run is why I never crewed much in Top Fuel, lol. I used to marvel at what went on in the pits with the AA Fuel dragsters and funny cars in between rounds at NHRA regional and nationals as we made our way back to the pits with our 9.42 second big block gas burning door slammer. When I crewed on one briefly, they only made about 3300hp....
 
harrym....Great rendition! I've never seen that before....'Well Done'! The saddest thing of all is that the Only 'Glory' it this level is in "Winning"! From a 'crew-members' point of view....He has too LOVE it, cuz he is NOT getting rich and there is no long-term employment/benefits. When I was a LOT younger....I wanted too do the 'tour' for Just 1yr! (never happened)
 
When I was coming through airport security at LAX yesterday right behind me was John & Laurie Force, Ashly Force with kids, and Robert Height. The Force's were pretty occupied with the two small kids but were friendly. I said hi to Robert and mentioned I was a fan of both drag racing and the Force team and he started talking to me like someone he had known forever. He seemed like a truly down to earth and nice guy, I was impressed. After we all made it through security Robert even took me over and introduced me to John and Ashley who were both very friendly. If I hadn't already been a fan they certainly would have made one out of me.
 
I was just at the Joliet NHRA Nationals. So, Harry has a couple facts that are a little off. Spark plugs are not thrown away after every run, where they would have to be if the ground electrode was gone. They have a rev limiter ( built in the Mags/ignition system ) set at somewhere around 8000rpm. While it is true if you hit the Mag kill switches, the engine will not shut off, the fuel must be shut off to stop the engine. Also, 11.2 gallons per second has to be incorrect. The cars don't hold 40 gallons of fuel. A lot of the fuel is tossed out the pipes at idle, but if they are all lit, there is little fuel wasted IMO as you cannot see anything but FIRE coming out the pipes. The "fast" guys with unlimited $ run around 55 - 60 degrees timing, with the mags being split a couple degrees. They run 50# boost. The "spec" gear ratio is 3.00 to 1.

Dave E.
 
I'm sure it has changed. The info I posted is probably a few years old. I was impressed at the PRI show when I asked a guy what the 2, 4" braided steel lines were, and he said they were fuel lines.
 
DGE53 said:
I was just at the Joliet NHRA Nationals. So, Harry has a couple facts that are a little off. Spark plugs are not thrown away after every run, where they would have to be if the ground electrode was gone. They have a rev limiter ( built in the Mags/ignition system ) set at somewhere around 8000rpm. While it is true if you hit the Mag kill switches, the engine will not shut off, the fuel must be shut off to stop the engine. Also, 11.2 gallons per second has to be incorrect. The cars don't hold 40 gallons of fuel. A lot of the fuel is tossed out the pipes at idle, but if they are all lit, there is little fuel wasted IMO as you cannot see anything but FIRE coming out the pipes. The "fast" guys with unlimited $ run around 55 - 60 degrees timing, with the mags being split a couple degrees. They run 50# boost. The "spec" gear ratio is 3.00 to 1.

Dave E.
Click to expand...

The only thing that may be slightly out of date in post #5 is the national record, which is under 4 seconds now for AA Fuel dragsters, but even that may not have changed, as for safety reasons due to the super high top speeds, the length of the Top Fuel run was reduced, I believe to 1000 feet, in about 2008, and the current 3.7 second record is for 1000', not 1320'. Nothing else has changed significantly since then as far as that description of what goes on inside a AA Fuel dragster engine was developed. And the fire you see coming out of the pipes at full tilt IS there because of unburned fuel, as stated - they use huge amounts of fuel, partly to make horsepower and lots more simply to cool the valves and piston crown, especially the exhaust valves; overfueling is the simplest way to cool within the combustion chamber, which has been true for decades in Top Fuel. That was and remains the reason for all that fire coming out of the pipes. As an aside, all that energy coming out of the pipes also contributes to downforce, helping rear traction, though not as much as the rear wing. If they don't destroy spark plugs in one run now, it's either primarly because of a rule change I have heard about but never bothered to verify, or improved plugs. When I was associated with AA Fuel class efforts years ago, the basic recipe (for both motorcycles and 4 wheel dragsters), which you modified slightly to suit conditions, was 92% nitromethane and the remainder propolyene oxide and up to 5% water (to cool the exhaust valves, primarily) to make up the other 8%. I heard, a number of years ago, that the NHRA invoked a rule limiting nitro to a lower figure and they are using more methanol now, instead of or in addition to propolyene oxide. The 11.2gps figure is quite correct also, but it is not the average figure, it is peak flow. Total fuel consumption for one run (burnout to shutting down) is between 22.5 and 23 gallons with the 1000 foot distance. Nothing wrong with Harry's facts.
 
Spark plugs are never reused. The spark plug companies give us cases of plugs.
A top fueler does not burn 11 gal of nitro per second, under full power.
The percentage of nitro allowed has been changed a couple of times.
It was lowered to (according to my faulty memory) 80% several years ago.
About a year later, thanks to the intervention of the fueler owners, it was boosted back up, to I believe.....90%.
At no time was 100% ever run....and in fact, the per cent used was and is a tuning factor.

The speed and ET records for the 1320 feet, are permanently held as a separate record. The 1000 ft. record is it's own.
 
At one time not too long ago, all the Nitro in the USA was imported from China. It still may be, I am not sure. It was a Synthetic Nitro, made from ???? Don Schumacher ( yes, the "Don" ) had exclusive Import rights to the stuff, if you wanted any, you had to get it thru him, Or I guess one of his "distributors". Paul, the percentage has bounced around the past few years, seems it is 80 or 85% maybe 90 I don't remember for sure.

One dragster that was really neat was Bruno Massell's I/D. It has a 4 cylinder Ecotech GM motor, with a BIG turbo on gas. It ran 6.64 at over 207 mph in the 1/4 mile, qualified 2nd in Comp Elim. Neat little dragster.
 
harrym said:
Paul....maybe you should re-write how it is, that way we will all be up to date.
Click to expand...
What is it you want to be rewritten?

Also.....for years Don Schumacher sold nitro to racers. He was never a sole supplier.
His came in drums, 50 at a time, from China. He actually uses nitro in one of his factories in a manner unrelated to racing.
(In fact, while I worked for DSR, a plant manager almost went to jail for improper storage of nitro, at the plant where it was stored.)
Then NHRA gave VP a contract to supply all NHRA fuel racers with their product.

At that time DSR was no longer allowed to supply anyone fuel, was not allowed to run his own fuel, and the price of fuel, promptly tripled. Obviously VP being allowed to charge whatever....NHRA benefited greatly by this policy.

About 5 years ago, the price of fuel had gotten so out of hand......55 gallon drums were now 43 gallons. The price went from a few hundred dollars for a true 55 gal. drum to $2300 for the "new" 55 gal drums.

The cost of everything was up...of course...and the price of fuel had gotten to the point where it was becoming a factor in whether or not some of the less funded teams could remain in NHRA fuel racing.
This included all vehicles using nitro for fuel.

At one point Schumacher began to press his desire to supply fuel for the lesser funded teams.....and was flatly turned down by NHRA.
I personally attended a meeting (one of several) in which this subject was thoroughly aired.
Schumacher, being the businessman that he is, gave compelling facts and financials as to how the
cost of fuel was driving certain teams out of the racing business. The NHRA, having it's per cent from VP being threatened flatly refused to allow Schumacher to supply fuel, or even to have it in his possession at the race facilities.

The reasons the NHRA brought to that meeting were beyond basic untruth and foolishness.
They were protecting their own income stream from the sale of fuel, and did not have the
guts to bring that up in the meeting.
Like as if Schumacher didn't know how such things worked.
If there is anyone in racing who knows "how it works" in the boardroom....and instantly gets the
economic ramifications of all decisions....it is the Don........Schumacher.

Despite that, he brought along a supply of fuel, to use it himself for practice on the day after one of NHRA's scheduled races. Note: It is common for several teams to stay at a track for a day or two after a scheduled race, in order to "test and tune." Nearly every year the Monday after the Gator Nat'ls for example, MANY teams stay to practice.
This is a work day, but is also a LOT of fun/socializing/camaraderie (and occasionally even a job search ;)).

Anyway, after the NHRA handed down their self serving edict, and Schu brought some fuel strictly for his own use......NHRA got wind of this and fined Schumacher $100,000.00 for the offense.

Much to my surprise Don paid the fine......probably out of his petty cash.
 
Thanks for the update Paul; I knew that the price of nitro had gotten beyond way out of hand, but I've been out of drag racing so long that I didn't know that most of the cost increase was both directly and indirectly hitched to NHRA political games.

Don Schumacher always was a gentleman and a scholar of the first order; drag racing is lucky to have him. Were it me hit with that fine on Practice day after the Gator Nationals, I would have told them to go pound sand and found another form of racing to support with my machinery, my presence and my $$$. And the AHRA, if it still exists, probably would have welcomed him with open arms if he left but wanted to stay in drag racing....

Captain11, oil, as you surmised is one-and-done. The only one I ever changed oil for had an 8 quart sump, but that was back in the days when they only made about 3300hp. Even then, the sump comes off the bottom, the supercharger, injection and heads come off the top, and the entire engine is essentially rebuilt in between rounds with the short block sitting there in the chassis. The better funded teams even had boxes of sets of 8 pistons with rods, rings and rod bearings all set to go with + or - labels marked on the end of the box. The rods used had an oval shaped small end so the center to center distance between the rod bearing journal and the wrist pin journal could be varied for more or less popup of the piston out of the block. Since you often replaced all 8 pistons and rods between each round, this offered a quick way to increase or decrease compression to adjust hp for track conditions if traction was down (less popup or even negative piston crown to deck measurement), or more height if there was enough traction to allow more hp - more height from the "0" rod length.
 
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