When the Indianapolis 500 runs on Memorial Day 2011, it will be the last in which the cars are powered by the V-8 engines that have won every year since 1978.
While we might consider the V-8 to be the natural racing powerplant, Indy Car racing had long been dominated by the Offenhauser engine, a four-cylinder engine that evolved into turbocharged form producing 1,000 horsepower at the time of the engine’s last victory in 1977.
Small-displacement turbocharged engines are not just the Indianapolis Motor Speedway’s heritage, they are its future, because starting in 2012 the Indy Car series will switch from today’s 3.5-liter V-8 engine configuration to 2.4-liter turbocharged engines featuring fuel-saving direct fuel injection and burning pump-available E85 ethanol fuel.
The league made the change at the behest of carmakers who are anxious to use racing to develop technologies that are relevant to their next generation of fuel-sipping production cars.
Chevrolet and Honda have announced that they will use small V-6 engines, while Lotus has said it will produce an engine of unspecified configuration and Volkswagen is said to be mulling a four-cylinder entry that would mirror the company’s popular four-cylinder turbo engines.
“The new engines are going to be much more relevant to what we are making,” explained Mark Kent, director of GM racing. “I think about everything we are going to see in the race engine is going to be applicable either directly or indirectly to the street engine.”
What kinds of things? Minimizing internal friction for maximum efficiency, turbocharging, and the use of direct injection with E85 ethanol. Historically, Indy Cars burned methanol (wood alcohol), but in recent years switched to ethanol (grain alcohol) with 2 percent gasoline added to give its flame color in the event of an accidental pit fire.
Now they will switch to the 85 percent ethanol/15 percent gasoline mix, which reduces the amount of renewable fuel in favor of more fossil fuel, but in doing so puts the race engines on the same fuel as many production models, making the know-how gained from racing legitimately useful for manufacturing cars that burn something other than 100 percent gasoline.
These small displacement engines make power by revving to high rpms, but making direct fuel injection work with E85 at high revs is a challenge reports Paul Ray, president of Ilmore Engineering Inc., the race engine company that will be supplying the Chevy race engines. “We will be pushing the limits of the technology,” he said.
The turbocharger control systems will also be very complex, because at some tracks the engines will run low boost, with medium and higher boost at other circuits. It will also feature a “push to pass” feature that gives the driver extra power for a limited interval.
These smaller engines will not only help manufacturers perfect fuel-saving engine designs for customers to use in their daily cars, they will also have the added benefit of being less expensive. According to Erik Berkman, president of Honda Performance Development, a season-long lease of one of its 2012 race engines will cost racing teams 40 percent less than the lease for its 2011-spec V-8s.
In the past, turbocharged engines cultivated a less-than-enviable reputation for reliability because of the high temperatures and stresses in boosted engines. But modern materials, assembly techniques and control systems are supposed to make turbos just as reliable. Honda’s V-8 race engines have set the bar high for the new engines: between April 2007 and August 2009 Honda engines powered the entire field of Indy Cars in every single race, a total of 244,880 racing miles, without an engine failure.
So if consumers find themselves driving cars whose engines are smaller, more efficient and less costly, without sacrificing power or reliability, they may have the 2012 Indy 500 to thank for it. — Dan Carney, Motor Matters
Copyright, Motor Matters, 2011