IndyCar mandates twin turbos in 2014 (2nd Update)

UPDATE #2

Honda IndyCar engine
Chevy IndyCar engine

INDYCAR has announced that all engines for the IZOD IndyCar Series from 2014 forward will be equipped with twin Borg-Warner turbochargers. IndyCar engines represent remarkable feats of engineering and experience. These 2.2 liter (135.25 cu in) turbocharged V6 engines weighing a mere 114 kg (250 lbs) pump out 650 to 750 horsepower at up to 12,000 rpm. A combination of direct and indirect fuel injection allows these tiny engines to swallow the enormous amount of fuel needed to achieve such power.

Normal turbo boost is 21.75 psi for these mini-brutes, with a passing option allowing a temporary (15 to 20 seconds, depending on the track) increase to 23.2 psi. Ten such boosts are allowed during a race, after which the capability is self-terminated.

07/29/13
HPD technical director Roger Griffiths says that Honda would have been forced to go down the twin-turbo route with its next-generation IndyCar engine even if that configuration had not been mandated by the series.

"If there was going to be no adjustments to the parity I think we'd still have had to have gone with the twin-turbo," Griffiths told Autosport.

"We cannot continue to fight with one hand behind our back, which is where we are today. IndyCar has admitted that there is not parity between them at any of the boost levels, so we're racing at a deficit at every event.

"In terms of outright performance, you're probably looking at a two or three per cent [difference]. It varies with the boost levels – at lower boost levels it's not so bad, but at higher boost levels it's pretty significant." Autosport

07/25/13 INDYCAR announced today that all engines supplied to IZOD IndyCar Series teams will utilize only twin turbocharger systems beginning with the 2014 season.

The decision, which was confirmed after consultation in an INDYCAR Engine Committee meeting, will further strengthen engine parity. It also dovetails with the manufacturers' first homologation update cycle for the 2.2-liter, direct-injected V6 engines supplied by Chevrolet and Honda.

"In an effort for parity throughout the turbocharger range, mandating only a twin turbo system simplifies our efforts to ensure even closer competition," said Derrick Walker, president, competition and operations, INDYCAR. "Both manufacturers displayed a willingness to use a common turbo spec for 2014, so it made sense to mandate a twin turbocharger that maintains the performance we've come to expect while keeping the technology relevant to the automotive industry."

Engine manufacturer competition returned to the IZOD IndyCar Series in 2012. Chevrolet re-entered the series with a twin-turbocharged engine through technical partner Ilmor Engineering. Honda, which was the sole engine supplier from 2006-2011, opted for a single turbocharger for the engine designed and built by Honda Performance Development.