Acceleration Put into Perspective

[Kurt Rahn]

Sorry for the long post, but I thought some of these were fascinating. I've never been much of a fan of drag racing, but some this is amazing to think about...

* 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 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 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 caught, but nearly blasted you off the road when he passed you within a mere 1320 foot long race!

[Bob Beamesderfer]

Head bolts are carefully engineered so that they won't stretch at least before the end of the run. Regardless, they're tossed out after each run. Teams have fiddled with diameter vs. number of bolts to find the right combination that prevents stretching, pull-out and snapping.

I got a close look at Ford's new Top Fuel engine last year at SEMA. It's stunning how big it is for the displacement. There's a lot of metal there.

[Chuck Fowler]

and no matter what name they cast into them, they're all based on a 50 year old chrysler hemi

[Bob Beamesderfer]

and no matter what name they cast into them, they're all based on a 50 year old chrysler hemi

Because they have hemispherical combustion chambers? I don't think Ford or Chevy would agree with that.

[Will Kalman]

I've also heard that the crank twists up to 20 degrees under load! I suppose they have to machine the cams to match that twist rather than machining them "straight".

[Chuck Fowler]

and no matter what name they cast into them, they're all based on a 50 year old chrysler hemi

Because they have hemispherical combustion chambers? I don't think Ford or Chevy would agree with that.

i'm sure they wouldn't

[Earl Merz]

Dual magnetos supply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.

My 185 amp welders would disagree with that. Now, will my welders ever put our 185 amps with what I use them for, no. but they still have the capacity to do it.

[Steve Collins]

Hydrogen flames are essentially invisible. (The Shuttle program has to use special IR cameras to look for them.) The white light must come from something else.

[Casey Brier]

Ive always been told the white light is Plasma.... look it up.

Speaking of drag racing, is anyone going to the winner nationals in November?... Michelle and I will be there. Section 6, Row 17! :gpower: (used to be section 3 which is RIGHT on the starting line, but we liked it better when we moved down just a bit)

[Steve Ekstrand]

I'm not sure about the head bolts thing.

They use studs, and they aren't replaced every run as far as I know.