Differences Between Top Fuel & Alcohol Dragsters

by Ma Wen Jie

Top Fuel dragsters and Alcohol dragsters burn different types of fuel. The fuels burn in different ways, thus creating different levels of performance on drag strips. Dragsters that burn alcohol are often called Top Alcohol class dragsters. The Top Alcohol dragster class is ranked just below Top Fuel. Top Fuel drivers are often required to drive Top Alcohol before being approved to drive Top Fuel. Top Alcohol engine size and power limits are usually lower than for Top Fuel.

Fuel Mixtures

Top Fuel cars burn a highly volatile mixture of 90 percent nitromethane and 10 percent methanol alcohol. Nitromethane is a highly combustible, highly explosive fuel that is also used in rockets and model airplanes. Top Alcohol cars generally burn methanol, although a few burn ethanol. In some cases, for injected engines with no supercharger, Top Alcohol cars can burn a percentage of nitromethane.

Superchargers

Not only do Top Fuel cars burn a highly volatile fuel with high power output, they also always implement superchargers to achieve maximum power output. Top Alcohol cars are allowed to use superchargers if no nitromethane is added to the alcohol fuel mixture. Top Alcohol cars that burn a percentage of nitromethane are not allowed to run superchargers.

Engine Size

Top Fuel engines are hemispherical head (Hemi) 500 cubic inch displacement (CID) (8.2 liter) engines. Although they produce less power, Top Alcohol engines are slightly larger than Top Fuel. Top Alcohol engines are 531CID (8.7 liter). The reason that Top Fuel cars can not have larger engines is the explosive quality of their nitromethane fuel. Top Fuel engines must have thicker cylinder walls to ensure that the energy from the fuel burn doesn't blow out the size of the cylinder.

Acceleration

Top Fuel dragsters accelerate from 0 to 100 mph in 0.8 seconds. Top Fuel drivers experience up to 8 G during initial acceleration. Top Alcohol dragsters can accelerate from 0 to 100 in 1 second. Drivers of Top Alcohol dragsters can experience as much as 4 G during the initial acceleration of the car.

Top Speed

Top speeds for Top Fuel dragsters can be as high as 335 miles per hour (mph). Top speeds for Top Alcohol dragsters are between 270 and 300 mph.

Risk

The extreme explosiveness and volatility of the fuel for Top Fuel cars is a risk. Although both classes have all of the inherent risks of drag racing, the increased speed and power of Top Fuel cars increase risks for drivers of Top Fuel cars.

About the Author

Although he grew up in Latin America, Mr. Ma is a writer based in Denver. He has been writing since 1987 and has written for NPR, AP, Boeing, Ford New Holland, Microsoft, RAHCO International, Umax Data Systems and other manufacturers in Taiwan. He studied creative writing at Mankato State University in Minnesota. He speaks fluent Mandarin Chinese, English and reads Spanish.

Photo Credits

  • photo_camera Photo: Kenn Kiser, morgueFile