Thread: drag racing - some useful info

Subject: Year 11 Physics. Speed, Energy, Acceleration.

Year 12 Chemistry. Energy and rates of reaction.

Uni Philosophy 1. Scientific Trivia and deduction
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First, 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 1½ 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.

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 $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 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.

There have been several attempts at trying to run top fuelers with turbos rather than a supercharger and even one attempt that i know of with a car trying to run both, in a sequential format [i.e. supercharger then feeds exhaust gases to spin the turbos].

The main problem with the twin design was the exhaust gases are produced in such volumes, so quickly, that it used to push the turbos off the block.

I think the problem with using turbos anyway is that nitromethane burns at such a high temp, the exhaust gases are so hot they tend to bugger the turbos up pretty quickly.

CaptJimmy