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Offline TMKIWI

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A lesson in Acceleration
« on: July 08, 2011, 03:12:24 PM »
> First, some useful info:
>
> One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower
> than
> the first 4 rows at the  Indy. 500.
>
> Under full throttle, a Top Fuel dragster engine consumes 1.5 gallons of
> nitromethane 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 nitromethane the flame
> front temperature measures 7050 degrees F.
>
> Nitromethane 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.
>
> The crankshaft twists so much that the camshaft lobes are ground offset
> from
> the front to the rear to re-phase the vave timing to achieve
> synchronisation
> with the pistons.
>
> 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!
>
> 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
> US$1,000.00 per second or around US$4,500.00 per pass.
>
> The current Top Fuel dragster elapsed time record is 4.441 seconds for the
> quarter mile (10/05/03,Tony Scumacher). 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 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 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.
>
> That, folks, is acceleration.
If you don't fall off you are not going hard enough

Offline Mr Tibbs911

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Re: A lesson in Acceleration
« Reply #1 on: July 08, 2011, 03:35:22 PM »
I bet if you repainted that Honda blue it would go faster. ::)

P.S. This thing would have some acceleration...

Tul-Aris 2-stroke racer
« Last Edit: July 08, 2011, 06:02:23 PM by Mr Tibbs911 »
ONLY TWO-strokes belong on TWO wheels.

Offline yo_marc

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Re: A lesson in Acceleration
« Reply #2 on: July 14, 2011, 09:14:28 AM »
Drag racing is another sport I love.  The sound of those Nitro motors when they launch.  I cant even consider it sound -- it's a concussion that tears through your chest.

Was at big race weekend ages ago, and was cruising the pits.  Saw a motor torn down with the last runs blown motor parts on a table for display.  The motor had lost a head gasket during its pass, and the hot combustion gases burned a hole through the aluminum head along the mating surface -- as if someone hit it with oxy/acetylene.  I'm not sure if the block survived.

The head was HUGE.   I can't imagine how expensive one of those things are... let alone to consider all of those parts to be consumable.  I can't figure how how anyone can afford to run them.

What's the saying?  Gasoline is for cleaning parts, alcohol for drinkin, and nitro is for racing?
'00 RM250
'88 TRX250R

Offline msambuco

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Re: A lesson in Acceleration
« Reply #3 on: July 24, 2011, 08:11:45 PM »
Long time ago I went to the Snowbird Nationals at Desoto Raceway near Sarasota FL. One car did blow the head off near the starting line. I remember seeing the glowing orange cylinder holes in the nightlight as though it was yesterday. Thanks for all those facts that I always appreciated but never knew.
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