Gordon Kirby

IndyCar’s engine war

This year’s IndyCar series has been re-invigorated by the return of competition between engine manufacturers. Honda was IndyCar’s sole supplier over the past six years but this year’s new 12,000rpm-limited 2.2-litre turbo V6 Formula has inspired serious competition from Chevrolet. Designed and built by Ilmor in the UK, Chevrolet’s Turbo V6 made a roaring start, winning this year’s opening four IndyCar races, all with Team Penske, before Honda bounced back at Indianapolis with much improved ‘step two’ engines.

In qualifying at Indianapolis the Chevy-powered Penske and Andretti teams swept the front two rows of the grid, but Honda’s updated engine arrived for the race allowing Dario Franchitti and Scott Dixon to score a resounding one-two for Chip Ganassi’s team and Honda. IndyCar’s new formula requires each driver to put 1800 miles on an engine before a change, resulting in the use of five engines over the course of the season.

Honda Performance Development’s Assistant vice-President Steve Eriksen told me Honda will focus its development work on reining details of the pistons to achieve better combustion and efficiency. “I think the fuel eficiency of the latest engine is a step up from what we had before and certainly a step up on power as well,” Eriksen observed.

“We’ve laid out the plan for the year and each one of those five engines will be a step up based on what we can do within IndyCar’s homologation specifications.” Eriksen said HPD’s engineers are delighted to have plenty of development work on their plates this year. He’s particularly pleased to be working on direct injection. “It’s one thing to do direct injection with gasoline but another thing with the low rates of ethanol,” Eriksen said. “Running at 12,000rpm with ethanol your injection window is so short and you’ve got to get so much fuel in there that it’s not really atomised at very high pressure. We’re excited about all the possible reinements of injectors, spray patterns, atomisation and all the things you need to do to make it more eficient.”

Ilmor boss Mario Illien agrees about the technical challenges to IndyCar’s new formula. “There’s so much calibration and mapping to be done with turbocharging and direct injection,” Illien said. “That was a challenge in itself, especially direct injection with ethanol, and we continue to work on the dyno to make it better.”

Takuma Sato drives Bobby Rahal’s Honda-powered IndyCar this year. Rahal analysed the battle between Honda and Chevrolet so far. “You have to acknowledge that Ilmor has done an extremely good job with the Chevy programme,” he said.

“There’s a tremendous amount of indycar experience at Ilmor, particularly with turbocharged engines, and I think frankly that was its advantage in the short term. Initially, Chevy had a bit of an advantage on both power and fuel mileage and better response on street courses because of its twin turbo.

“On the Honda side there’s a lot of newer people with less experience. However, the HPD management is very experienced and Honda has reacted very aggressively to the situation and showed what it can do in the race at Indianapolis. I believe Chevy has awakened a sleeping giant and i think the race is on now.”

Meanwhile Mario Illien looks forward to 2015 when IndyCar hopes to open up its engine and chassis rules. “I think the engine rules we have now is quite a good package,” Illien commented.

“I’d like to maintain that. But if we can combine it with a proper hybrid solution I think that is the way forward because you talk about better economy and relevance to road cars. It would be more difficult to introduce in IndyCar because of the ovals, but on the road courses I think it’s got to be part of the future.”

After a decade of technical torpor it’s encouraging that IndyCar has begun to get itself back on track as a competitive, cutting-edge form of motor racing.