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Pampered-Z · 11-30-2005, 09:30 AM

The reasoning for shutting down early is because of the time it takes to actually shutdown the motor ( only way is to kill the fuel flow - noted elsewhere) )and distance a topfueler is traveling. Remember the motor is igniting the fuel by the compression and heat, much like a diesel engine, so it takes time before the fuel lines empty and the engine to shutdown. Think about it, if you pull the fuse to your fuel pump the car will run for some time until the pressure drops, it is not like turning off the ignition.

And remember at 300+ MPH your covering allot of ground VERY quickly. The engine is turning at 9,000+ RPMs and the clutch is locked in so you have an engine you can't turn off that is direct drive to the tires. Momentum is going to keep the engine turning over too.

So, if the driver shuts off the fuel and pops the chutes at say 1,100' (the footage is just my guess for this example, I don't think they are trying to say this happens at 1/2 track, just that the driver does wait until he crosses the finish line before he starts the shutdown).

By the time the chutes deploy and the engine stops firing they have crossed the finish line. They are still 'running it out the back door'.

Doesn't matter if they hurt parts, they expect to hurt it and besides, they're tearing it completely down between rounds anyway!

11-30-2005, 09:30 AM	#12
Pampered-Z Sliderule / Moderator Join Date: Oct 2004 Location: Catawissa PA Posts: 2,294 iTrader: (1)	The reasoning for shutting down early is because of the time it takes to actually shutdown the motor ( only way is to kill the fuel flow - noted elsewhere) )and distance a topfueler is traveling. Remember the motor is igniting the fuel by the compression and heat, much like a diesel engine, so it takes time before the fuel lines empty and the engine to shutdown. Think about it, if you pull the fuse to your fuel pump the car will run for some time until the pressure drops, it is not like turning off the ignition. And remember at 300+ MPH your covering allot of ground VERY quickly. The engine is turning at 9,000+ RPMs and the clutch is locked in so you have an engine you can't turn off that is direct drive to the tires. Momentum is going to keep the engine turning over too. So, if the driver shuts off the fuel and pops the chutes at say 1,100' (the footage is just my guess for this example, I don't think they are trying to say this happens at 1/2 track, just that the driver does wait until he crosses the finish line before he starts the shutdown). By the time the chutes deploy and the engine stops firing they have crossed the finish line. They are still 'running it out the back door'. Doesn't matter if they hurt parts, they expect to hurt it and besides, they're tearing it completely down between rounds anyway! __________________ 93Z M6 Black: The 385 Lives! Supercharged, 3-core front mount intercooler, GTP heads, 3:73's, Street twin clutch, Jethot Longtubes, Mufflex 4" catback/spintech, S+W cage, Spohn Suspenion, Yada Yada Yada 1) Build it 2) Race it 3) Break it 4) Repeat!!! Last edited by Pampered-Z; 11-30-2005 at 02:04 PM.