Ford Power Stroke Nation banner

Acceleration Facts

4447 Views 30 Replies 17 Participants Last post by  smorris
A Lesson in Acceleration:

First, some useful info:

* One NHRA Top Fuel dragster 500 cubic inch Hemi
engine makes more horsepower than all the cars in
the first four 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 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

* 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

* 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, and if,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 for you
bikers: You are riding the average $250,000 Honda
MotoGP 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 catches and passes you. He
beats you to the finish line, a quarter mile away=20
from where you just passed him.

Think about it, from a standing start, the
dragster had spotted you 200 mph and not only
caught you, but nearly blasted you off the road when
he passed you within a mere 1320 foot long race course.

That, folks, is acceleration .
See less See more
21 - 31 of 31 Posts
Really?? I wonder what kind of Dyno could handle that kind of engine. That would be something to see, a top fueler on a dyno.
If I remmember right it was an old arse stuska water brake dyno not real sure it was back when they estimated a fuel engine cranked out some serious 4 digit hp #'s tho.
The cool thing about an AA Fuel motor...they burn the tips of the plugs off as the run starts and DIESEL the rest of the way.
And they say real diesels don't need spark plugs. LOL
Could you explain what is is ment by when you say that the engine is only supposed to last or live 900 revolutions under full load.

I guess I am confused as to what that means.
Top Fuel - one run - one engine. They do a complete rebuild after each run. I have seen them pull and engine/trans and drop in a new one in about 20 minutes. Looked in the trailer and there was a line of them in there. Big budget racing!!
They used to rebuild the engine that was in the car right there on the spot. Complete teardown, inspection, rebuild.

I guess with the money they have now tho, they can afford to just swap the entire engine in one go.
I got into a slight argument with a pilot on the USS Nimitz years ago when I was in Highschool and we got a tour of the air craft carrier.

The pilot was explaining the catapult system on the ship, and how the steam catapults launch the aircraft into the air at about 4 G's.

I replied "Is that all?", and and he goes on about how its the hardest acceleration etc etc and I proceeded to give him the heads up about 6-8 G launchs that top fuel cars do.
10-4, one of the top guys had to retire becuase of detached retinas. (may be wrong..It might have been John Force) Anyway, the doctors told him one more time and he'd be blind. Thats some real acceleration!

Also, you know how they balance the load from cyl. to cyl on those motors?? Rod length.
Pretty high tech crap.

Me likes.:redspotdance:.
I saw an "updated" one of these top fuel facts sheets the other day, and it stated that in order to compensate for the amount of twist in the crankshaft, they grind the cams with a progressive twist towards the back of the block.
Wasn't John Force. He's still crankin down the track and trying to recover from a tough year.
It is not to compensate for crank twist, but cam twist, yes the cams are ground with a twist in them. Because of the valve train loading, engine acceleration and physical size of the cam it'll try and twist in half. Unlike other classes, top fuel cars leave at idle so the engine acceleration is much more pronounced.

I helped on a car that was run mostly out of pocket of the guy who owned it. It costs around 7K per pass when you consider things like the clutch stack, tires, engine parts, etc. The engines have to be torn down after each pass mostly just due to the heads. We had to check the heads and lap/replace valves - the big guys just pull the heads off and they have a new set ready to bolt on. The bottom end has to come apart because of the amount of blow-by into the crankcase, the nitro destroys the bearings.

The car consistently went 60mph in 1 foot, and it's a slow car compared to the big money teams. The best we hoped to do was qualify. There wasn't enough time between rounds for use to go through everything after qualifying. That is where it takes the real money. Guys like the Army team and Force have two box trucks, one with all new parts such as heads/blowers, etc. and the other box truck for the used stuff. At the end of a race the team goes on to the next race and the box trucks go back to the shop. Two more box trucks will meet the team at the next race and they'll do it over again.
See less See more
Wasn't John Force. He's still crankin down the track and trying to recover from a tough year.
Nope, your right , it was Joe Amato
21 - 31 of 31 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.