[sammyg2]

No nitroglycerin involved, different animal.

From wikepedia:
Nitromethane is an organic compound with the chemical formula CH3NO2. It is the simplest organic nitro compound. It is a slightly viscous, highly polar liquid commonly used as a solvent in a variety of industrial applications such as in extractions, as a reaction medium, and as a cleaning solvent. As an intermediate in organic synthesis, it is used widely in the manufacture of pharmaceuticals, pesticides, explosives, fibers, and coatings. It also finds use as a racing fuel.

Nitromethane is used as a fuel in racing, particularly drag racing, to provide more power. In this context, it is commonly referred to as "nitro" or "fuel".

The oxygen in the molecular structure of nitromethane enables it to burn with much less atmospheric oxygen in comparison to hydrocarbons such as gasoline. Part of the oxygen needed for combustion is carried by nitromethane itself. At stoichiometric the combustion will be as follows:

4CH3NO2 + 3O2 Ļ 4CO2 + 6H2O + 2N2
14.6 kg of air are needed to burn one kg of gasoline, but only 1.7 kg of air are needed to burn one kg of nitromethane. Since an enginefs cylinder can only contain a limited amount of air on each stroke, 8.7 times more nitromethane than gasoline can be burned in one stroke. However, nitromethane has a lower energy density. Gasoline provides about 42-44 MJ/kg, nitromethane provides only 11.3 MJ/kg. This would indicate that it with nitromethane is possible to generate about 2.3 times the power of gasoline. This is however not the complete story, nitromethane can also be used as a monopropellant. Without additional oxygen nitromethane will combust according to:

4CH3NO2 Ļ 4CO + 4H2O + 2H2 + 2N2
Nitromethane has a laminar combustion velocity of approx. 0.5 m/s, that is somewhat higher than gasoline and makes the fuel suitable to engines running at high speed. Somewhat higher is also the flame temperature at about 2400‹C. The high heat of vaporisation of 0.56 MJ/kg together with the high fuel flow does however provide a high cooling of the incoming charge (about twice that of methanol), resulting in reasonably low temperatures. In a Top Fuel dragracing engine this alone will provide the cooling of the engine.

Nitromethane is usually used with rich air/fuel mixtures. This is partly because nitromethane can provide power even in the absence of atmospheric oxygen, as described above, but it's also because nitromethane tends to produce severe knock and pre-ignition. Rich mixtures do however cause ignition problems and a lower combustion speed.

When rich air/fuel mixtures are used, hydrogen and carbon monoxide will be two of the combustion products, when these and any unburned fuel comes into contact with the oxygen in the atmosphere at the end of the exhaust pipes they often ignite. The result is spectacular flames from the exhaust system.



BTW, if you think seeing them in person is a thrill, try running one of those engines on fuel directly behind you in an 18' flatbottom boat. I never got past about 40% nitro but that was more than enough.
Back in 1985 I was paying roughly $31 a gallon for the stuff, no idea what it costs nowadays.