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This a AA/FD, or Top Fuel Dragster. They're testing engine tuning in the pits.
Nitro doesn't really burn all that well, gas burns easier. Nitro is also expensive. They start these engines by squirting gasoline into the intake like starting fluid. After using the gasoline, this one uses Alcohol to get the engine hot. Once heat and compression are up they switch to nitro. The difference in sounds is very distinct, from a rough-running hot cam sound on the alcohol, to a popping or 'cackle' on nitro.
If you listen you can hear each individual cylinder igniting. Watch for the unburned fuel coming from the headers, that's how they keep the engine cool, there's no radiator. Watch for the flames too.
Points of interest:
At the beginning, you can see a crew member at the far right setting the starter down.
The engine is running on alcohol for a while, then the tuner switches it over to nitro somewhere around 1:05 or so. There's a period where it sounds deep and full when switching over. At about 1:18 it's starting to pop from the nitro taking over, and it hits full cackle a few seconds later. At about 1:50 the tuner checks throttle response a few times. At the end, he squirts gasoline into the engine to shut it down. I'm not sure why they do this during testing, I think it has to do with flooding the engine and leaving some gas in it for the next start, but that's just a guess and I could be wrong.
Clicking on the image will take you to Flickr, where you can view the video.
Turn it to 11!
AA-FD Test by Shotglass Photo, on Flickr
Nitro doesn't really burn all that well, gas burns easier. Nitro is also expensive. They start these engines by squirting gasoline into the intake like starting fluid. After using the gasoline, this one uses Alcohol to get the engine hot. Once heat and compression are up they switch to nitro. The difference in sounds is very distinct, from a rough-running hot cam sound on the alcohol, to a popping or 'cackle' on nitro.
If you listen you can hear each individual cylinder igniting. Watch for the unburned fuel coming from the headers, that's how they keep the engine cool, there's no radiator. Watch for the flames too.
Points of interest:
At the beginning, you can see a crew member at the far right setting the starter down.
The engine is running on alcohol for a while, then the tuner switches it over to nitro somewhere around 1:05 or so. There's a period where it sounds deep and full when switching over. At about 1:18 it's starting to pop from the nitro taking over, and it hits full cackle a few seconds later. At about 1:50 the tuner checks throttle response a few times. At the end, he squirts gasoline into the engine to shut it down. I'm not sure why they do this during testing, I think it has to do with flooding the engine and leaving some gas in it for the next start, but that's just a guess and I could be wrong.
Clicking on the image will take you to Flickr, where you can view the video.
Turn it to 11!
AA-FD Test by Shotglass Photo, on Flickr
