Acceleration!

One top fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows at the Daytona 500.

Under full throttle, a dragster engine consumes 1.5 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 drive the supercharger.

With 3000cfm 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 burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from the 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 ½ way, the engine is dieseling from compression plus the glow of exhaust valves at 1400 degree F. The engine can only be shut down by turning off the fuel.

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 300mph in 4.5 seconds dragsters must accelerate at an average of over 4G’s. In order to reach 200mph 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 approx. 540 revolutions from light to light(start to finsish).

Including the burnout the engine must only survive 900 revolutions under load.

The redline is quite high at 9500 rpm.

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 $1000(usd) per second.

Putting all of this into perspective:

You are driving the average $140,000 Lingenfelter TWIN TURBO Z06 Corvette. Over a mile up the road, a Top Fuel dragster is staged and ready to launch down the quarter mile strip as you pass. You have the advantage of a flying start. You run the Vette up through the gears and blast across the starting line and past the dragster at an honest 200mph. 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 200mph and not only caught you, but nearly blasted you off the road when he passed you within a mere 1320 foot long race track.

That folks, is ACCELERATION!

Info provided by Blue Bars

Funny cars are great. Whenever we used to go to the NHRA drags in high school we'd stand by the lanes as they made their passes. You can pretty much feel the flames shooting out from the sides when they pass. I remember watching my cellphone vibrate off the bleachers when one was making a pass. Its awesome stuff.

Top Fuel Dragsters & Funny cars are unreal in person. I haven't been to a NHRA event in 10yrs or so, but I am this weekend at RT. 66

Nothing beats jet cars when they do burner pops. Standing near them feels like some one hitting you in the chest.

National Geographic did some tests a few yrs ago & 2 nitro cars(dragsters/funny cars) hit 2.5 on the richter scale - small earth quake.

and why doesnt top fuel allow turbos?

I'm supposing that its not so much that they don't allow it. Its more how are they gonna put it to use without having the engine explode.

I'm pretty sure if they even made a turbo for those cars, it would need to be about the size of a beach ball, and when a pass is finished the remaining pressure would probably grenade the whole intake assembly. Besides, they're all standard with superchargers.

and why doesnt top fuel allow turbos?

plus the nitro methane takes so long to burn, it would still be burning inside the turbo, as jackasssi say, at over 7000F

plus turbos have a bit of a lag time, not very helpful when you have 4.5 seconds to work with...

If they were allowed to turbo I'm sure they would. Turbos are just too big of an advantage.
Turbos are more efficient than roots blowers and don't take away crank hp - as jackasssi said, it takes an awful lot of hp to turn that supercharger.
However, they may have to run a sequential system to build enough boost. With a roots blower, turning up the boost is as simple as changing the pulley sizes. I think the best system would be a turbo feeding a roots supercharger.

oh and check out my avatar if you're wondering if someone makes a turbo big enough.

oh they deffinately make a turbo big enough and turbos love that heat produced, that is what makes a turbo work. im pretty sure it is the advantage over the roots blower that makes them outlawed in top fuel.

This text contains several errors. For example:

Nitromethane burns with a flame temperature of 2400 degC (4350 degF), methanol reduces this. Nitromethane does also burn fast, it has a flame speed of .5 m/s, the rich mixture used in Top Fuel makes it burn slow.

44 amps is the primary current, the secondary current which is what the sparkplug sees is about 1.2 amps.

The cylinders does not run close to hydraulic lock, nor is the fuel almost compressed into solid. The top fuel doesn't consume fuel in the rate a 747 with full throttle do either, also while the 747 engine is very efficient and runs on a fuel with no oxygen content the top fuel engine is very inefficient and runs on a fuel with about 50% oxygen by weight. The 747 can outaccelerate the Top Fuel from standstill, but on the other hand it can break the sound barrier (yep, the big 747 can do that in the case you didn't know that) or blow the whole Top Fuel car off the track before it even can start.

The compressor consumes about 1000 hp from the engine, but roots blowers are very inefficient. This power could probably be gained with turbocharging.

In case of hydro lock, if the ignition would be cut off during a run the head gasket is what usually goes. That usually gives a green flame (copper burns green).

quotes

"There are tradeoffs in both systems. In theory, a turbocharger is more efficient because it is using the "wasted" energy in the exhaust stream for its power source. On the other hand, a turbocharger causes some amount of back pressure in the exhaust system and tends to provide less boost until the engine is running at higher RPMs"

http://auto.howstuffworks.com/question122.htm

"An interesting thing about nitromethane is that it does not burn as quickly as gasoline. In fact, there is not enough time to burn all of the nitromethane between when the spark plug fires and when the exhaust valve opens. So the engine is pumping still-burning nitromethane into the exhaust pipe. That's why you see flames shooting out of the exhaust of a drag-racing car."

http://auto.howstuffworks.com/question642.htm

"To get the largest possible amount of air, for the oxygen, into the engine it is force fed by a blower. The blower is similar to a turbo but it’s mechanically turned directly from the crankshaft and revolves about 30-40% faster than the engine. The compression is done by means of two spiral twisted rotors going in opposite directions. Screwtype blowers are not permitted in the regulations"

"Since nitromethane burns slowly the timing is set to 50-60 degrees before TDC. The nitromethanes long burntime is what’s responsible for the high flames coming out of the exhaust pipes when driving. The fuel hasn’t finished burning and is pumped out flaming."

http://www.topfueltour.com/english/teknik.htm

"Look at Top Fuel dragsters.. you know.. the 6000HP Monsters, what they running? S/C's. In MANY drag leauges it takes a Twin Turbo HIGH boost setup to match one well done S/C setup in a 1/4 Mile.

Also S/C boost is NOT always dependant on RPM. a Roots style S/C has Full boost at 1600 - 2000 RPM and holds at that same boost level though the entire RPM range. If you were going with an autoroto system yes the boost would be dynamic to the RPM. But this is why most people run a Roots system. S/C will ALWAYS deliver more power, faster and higher torque at lower RPM's than a turbo. Which means while you are banging off the rev limiter to get yer turbo running to its top performance, the S/C doesnt need that as there is NO spool up time."

http://forums.nasioc.com/forums/archive/index.php/t-80752.html

"The supercharger's mechanical link to the engine means it is an "instant-on" device. As soon as the engine is turning over, the supercharger is working. The turbocharger, on the other hand, requires a build-up of exhaust gas pressure to spool up, so there can be a lag between the application of throttle and the boost in power.

So, the basic advantage of supercharging over turbocharging is that you get power increases right off idle with no waiting for turbo lag. Those in the pro-turbo camp will be quick to point out, though, that there is a certain parasitic loss of power from the crank having to drive the blower. So when choosing a forced-induction system, here's your first decision: Do you want instant, off-idle response? Or are you willing to trade a little low-end grunt for every last ounce of horsepower your engine can create?"

http://www.eurotuner.com/techarticles/23618/

I don't want this to become a supercharger vs. turbo thread, there are already about 3,000 of those on automotive forums, go find one of em and talk there.

a turbo is not used in top fules because of many reasons.
1.) Nitro Methane is ran so rich that the nitro is still burning long after it leaves the exaust pipes. nitro also burns so hot, no it does not burn yellow...it burns an extremely pale blue, nitro methane is so effecient that nearly all of its stored energy is released as infared radiation (heat) and not color in the light spectrum....nitro fires are extremely dangerous because they cannot be seen in daylight...anyways that heat goinf through a turbo would blow bearings and cause fire in the dry sump system....
2.) The turbos needed to create that sort of boost would have to be turbos as large as used on 16.0 litre diesels...of which would over rev with so much exaust flow... lag has nothing to do wiht it since dragsters launch at high enough RPM's to where the turbo would already be nearing peak boost..
3.)turbos would free up hundreds of more HP...more HP=more stress=need of even stronger parts and tires with even more surface area

Top fules are kool, yes, i like jackassi said...each cylender makes more HP than one Nascar engine...but there are no gears to change...so driver basicly gets a good reaction time..gets and adreneline rush line none other...and goes for a ride hopeing and praying that nothing starts a nitro fire and he doesnt wreck...basicly a good reaction time and worlds largest balls is what you need to race top fule or funny car...racing 9 seond cars take a tad more skill and a lot less balls... to me drag racing is an mechanics competition...not a driver competition...besides reaction time...as for you blowing off the 190,000 vett...the vett wasnt made to go in a straight line...though it does well in the 1/4 mile..any one who buys a vett to take it to the strip deserves to be murdered and the car donated to me so i can put it to use for what it was designed for (road racing/autocross type driving)

There have been quite a few posts here that have less accurate information.

Turbochargers aren't used in Top Fuel for one simple reason; the regulations clearly state that only roots superchargers is allowed. The supercharger allowed have its orgin from a diesel engine.

In racing lag isn't a problem with the turbocharger, the turbocharger can be run basicly as a gas turbine before boost is needed. The temperature of the exhaust isn't a problem either, especially since we talk about a such short time. When using nitromethane with turbocharging the turbine section must be larger than with gasoline engines. By using turbocharging you also free up power the engine is already producing, but that is otherwise consumed by the supercharger. The backpressure the turbocharger cause will, if a efficient setup is used, be lower than the boost pressure.

The laminar flame speed at stoichiometric for nitromethane is .5 m/s, normal gasoline is about .35 m/s.

There are dangers with using nitromethane, it do indeed burn yellowish (methanol burns invisible at daylight, blue when dark), and when using more than 20% nitromethane there is always a danger for a sump fire. Nitromethane can also react with other fuels, and its exhausts contain nitric acids.

At which spectrum heat radiation is released at depends on the temperature, at low temperatures it's never visible. You need to reach temperatures similar to the sun if you want visible heat radiation. As with most combustions a small portion of the energy is released as light (photons).

In Top Fuel today, much of the secret to fast times is in the clutch, the engine is basicly operate on a constant rpm.

Nitromethane does have a high heat of vaporisation, in a Top Fuel engine some of the fuel is injected before the supercharger. The high heat of vaporisation with the high fuel flow cools the intake air and reduces the combustion and exhaust temperature.

all heat felt by us is infared radiation.

all heat felt by us is infared radiation.
No, there are several ways to transfer heat.

There are:

1. Heat transport through kinetic energy in the molecules. This is heat is transfered in for example a piece of copper. The copper can also transfer the kinetic energy better than for example iron. Typically measured in W/(m*K), for example copper 380 and iron 71 W(m*K). If you put your hand on a hot piece of metal I can guarantee you that you will feel that it's hot!

2. Convection is the heat transfer between a fluid and a solid wall. If the wall is warmer than the fluid the wall will heat the fluid through transfer of kinectic energy like in 1, however when the fluid is heated it density drop and the particles will flow upwards. This is how the cylinderwalls in an piston engine transfer heat to the coolant. And once again I can guarantee you that if you toch the hot coolant you will feel how hot it is.

3. Heat transfer through radiation. Radiation through electromagnetic waves can occur even in vacuum, which isn't the case with the two above. All objects at a temperature above 0 K emitts heat radiation, how much it emitts depends on a coefficient for the material and surface, and when the radiation hits and object some of it is taken up, the other is reflected. Some materials are very good to reflect, gold is one of them, and that is why whe can find gold in the engine bay of McLaren F1 as well as on some satellites. On the other hand, if the object is "black" it will emitt all radiation that fells on it, but note that "black" isn't the colour black, snow is for example excellent in absorbing infrared radiation. The frequency of radiation depends on the temperature of the emitting object, the sun does for example emitt at such high temperature that the heat radiation is on the visible spectrum, this is why a black car exposed to sunlight gets hotter than a white one, black is here "black".

Just some thermodynamics 101...

^^ heat felt form a radiation source (ie the sun or a light bulb etc.) , my bad.

^^ heat felt form a radiation source (ie the sun or a light bulb etc.) , my bad.
Heat radiation felt from a light bulb is infrared, the heat radiation from the sun is not infrared, it's visible. This since the sun is so hot.