12-01-2004, 01:28 PM
|
 |
AF Fanatic
|
|
Join Date: Oct 2003
Posts: 3,262
Thanks: 0
Thanked 1 Time in 1 Post
|
|
|
check it out
this was put up in the off-topic forum, dont know if any of you people go there but i thought it was interesing enough for a repost here...
Quote:
|
Originally Posted by Ricochet
oldie but goodie
Subject: Horsepower & Acceleration
Some of us may think we have experienced acceleration g forces, but read this to get a grip of what real acceleration is.
But first, some useful info:
One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows at the NASCAR Daytona 500.
Under full throttle, a dragster engine consumes 1 1/2 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 drive the dragster 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 one pass. After half-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.
With the enormous cylinder pressures generated by "top fuelers", at full throttle, it's not uncommon to replace the .625" & .750" cylinder head bolts after a few runs, to prevent cylinder leakage due to the bolts being "stretched".
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.
The current Top Fuel dragster elapsed time record is 4.441 seconds for the quarter mile (10/05/03 Tony Shumacher) 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).
|
|
and amazing.
