a lesson in acceleration

warwgn

Explorer
A Lesson In AccelerationFirst, some useful info:*

* 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 Top Fuel dragster engine consumes 1 gallon 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 426 Hemi V8 engine cannot produce enough power to drive the dragster's super-charger.*

* 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.

** Nitromethane bums 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! This one confused Stan, but stop & ponder the fact that the engine is only used for appoximately 4 to 5 seconds.*

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

* The red-line is actually 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 $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 riding the average $250,000 Honda Moto GP bike. 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 RC211V hard up through the gears and blast across the starting line and past the dragster at an honest 200 mph (293 ft/sec). The 'tree' goes green for both of you at that moment. The dragster launches and starts after you. You keep your wrist cranked hard, but you hear an incredibly brutal whine that sears your eardrums and within 3 seconds the dragster catch-es 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.
 

Sangster

Adventurer
Lol, I was impressed with my almost stock 4.0L V6 the other day when the air was cool outside and it felt like an extra 20 HP.

Sent from my Nexus 10 using Tapatalk 4
 

Buliwyf

Viking with a Hammer
And Top Fuel dragsters are still just using olde 1960's technology and extremely technology limiting rules to keep them safe. No such thing as the quarter mile anymore. They're only racing 1000 feet.
-
500mph would be easy with modern tech in the 1/4, but not very sporting.
-
I talked to a racer that pretty much kept the NHRA going in it's weaker years. He actually did build a "cheater car" with modern FI just to see what would happen. Needless to say, it was a failure. Waay too much power and speed to race safely.
 

Saiyan66

Adventurer
Another couple cool factoids:

Top Fuel cars run 1 speed transmissions. Technically its just a gearset with a clutch that continually tightens up as the car reaches top speed.

The tires used are designed to "grow" with rpm which does two things. One, it allows the tire to not explode due to the forces applied to it. Two, it actually changes the final drive ratio as the car goes down the track.

Only one bit of false information in there that I have to point out. The four stroke Honda RC series GP bikes (211V, 212V, 213V) cost roughly $1M per bike to manufacture. And I would still take one over a top fuel dragster even though it gets monkey stomped in the 1/4 mile.
 
Last edited:

graynomad

Photographer, traveller
Yikes, of course we all know they are fast but that really puts things in perspective. I never knew how close to the edge they ran.
 

oldblue

New member
A Lesson In AccelerationFirst, some useful info:*

* Under full throttle, a Top Fuel dragster engine consumes 1 gallon of nitro methane per second; a fully loaded 747 consumes jet fuel at the same rate with 25 less energy being produced.*

While top fuel dragsters are impressive, this statement seems to be incorrect. The engines used on a 747 are vastly more powerful than those used in a dragster. A 747 at altitude and cruising thrust (not full throttle) still produces much more power than a dragster while still consuming around a gallon/second. The numbers seem to vary but I can't find anything that suggests that the stated proposition is even close to correct.
 

Buliwyf

Viking with a Hammer
I was spinning wrenches on a generator next to a Rolls Royce Turbine from a 737. That engine was a 16+ megawatt engine, a dragster doesn't stand a chance against #'s like that. Jets can make a ton of power if you have the fuel.
 

warwgn

Explorer
6000 ft lb of torque is a whole lot, not sure how to conert to watts but would bet it is close or more.
 

Buliwyf

Viking with a Hammer
Found it dragster at 6000 ftlb and 8500 rpm would be around 7.4 megawatts. I stand corrected.

But the turbine makes an honest 16+megawatts for hours. The dragster engine would likely fail to make more than 1meg if we bolted a gen to it. Only 5 seconds of run time before grenading doesn't exactly count either.

It's kinda like saying the I can move faster than a Formula 1 car. Because I sneeze at 200mph. LOLz.
 

DDW

New member
Impressive for an over the road car, but not in comparison with really powerful vehicles. The Saturn V rocket used in the Apollo missions puts it to shame: 1st stage engines generate a combined 150 GW power (150,000 MW), while burning 15 tons of fuel a second to generate 7.5 millions pounds of thrust. The fuel pumps alone consumed 55,000 hp.
 

Forum statistics

Threads
185,896
Messages
2,879,317
Members
225,497
Latest member
WonaWarrior
Top