After aerodynamics, power plants take pride of place in the no-limits race. Rockets merit consideration-retro-
rockets might be used to help a car turn and stop-and even nukes get a few votes. Hey, while we're at it, why don't we dust off the flux capacitor in Michael J. Fox's DeLorean? But seriously, folks, small gas turbines are the most attractive alternative to conventional four-stroke piston engines. In fact, cars powered by modified Pratt & Whitney helicopter turbines coulda woulda shoulda won the Indy 500 in 1967 and 1968 before (stop me if this is getting repetitious) being effectively outlawed. Turbines boast superlative power-to-weight ratios, and they're smaller and torquier than four-stroke piston engines. Also, thrust could be vectored, or angled, to help turn the car. What's not to like? Well, turbines suffer from throttle lag: They take time to spool up to speed, and they take more time to slow back down-not a good combo for racing.
That problem isn't unsolvable. But why bother? A quarter of a century ago, using exotic fuels and turbochargers running unlimited boost, Indy engine builders pumped 1,000 horsepower out of the venerable Offenhauser, a piston-engine design whose architecture predated World War II. The gargantuan engines in today's Top Fuel-class dragsters, which aren't much younger, make a whopping 6,000 horsepower (though, admittedly, only for a few awe-inspiring seconds). Contemporary Formula 1 cars get 900 horsepower out of 3.0 liters, or 300 horses per liter, without forced induction. "If we could use turbochargers and superchargers," says Robert Clarke, vice president of Honda Performance Development, "1,000 to 1,200 horsepower per liter wouldn't be unreasonable."