Turbo charging entering a golden agePOSTED BY Nigel Andretti ON 14 May 2015
WITH global environmental requirements putting the squeeze on, car makers are producing their smallest, most fuel-efficient engines ever, but to keep power hungry coustomers happy, are turning more and more the the use of turbochargers which help four-cylinder and even three-cyclinder engines produce astonishing power figures.
Through the ’90s, turbocharged engines represented a small slice of the market, largely relegated to European sports models and performance versions of American cars, and certainly the boy-racers’ fantasy — the Subaru WRX and Mitsubishi Evos.
Since then, turbocharged engines have expanded to about 21 percent of cars sold in the United States in 2014, still some way off Europe where about 70 percent of all vehicles now sold are turbocharged.
“We’re in the golden age of turbos,” Nitin Kulkarni, Honeywell Transportation Systems vice president of North America, Japan and Korea told the Detroit News this week.
“We are a no-compromise solution because we can be literally applied to all kinds of vehicle sizes, fuels and engine strategies.”
Honeywell is a leader in turbocharger technology. The company, which works with nearly every major automaker and truck manufacturer in the world, consistently has 100 turbocharger technologies in the pipeline.
Driving the down-sizing and turbo revolution are global fuel economy regulations that will require automakers to have fleets that achieve 54.5 miles per gallon by 2025. “At the end of the day, it’s ultimately regulations that the manufacturers are trying to meet,” said IHS Automotive analyst Jeff Jowett.
Turbochargers work by using a high-rpm fan driven by exhaust gases to force-feed fresh air into the engine. More intake air means that more fuel can be added, and that delivers more bang for the buck.
“Turbocharging is truly one of the best cost-effective solutions,” said Kulkarni. “It is an ‘and’ technology, not an ‘or’ technology.”
Ford has been a leader in the turbocharging revolution with its EcoBoost engines (below). All of the Dearborn-based automaker’s vehicles — from the F-150 to the Mustang — offer EcoBoost engines.
Helping put the “Eco” as well as the “Boost” into the popular engine is a turbocharger. EcoBoost engines are relatively small-displacement engines that use turbocharging, gasoline direct-injection and variable valve-timing for the power customers want and the fuel economy they need.
The cost of a turbocharged engine can add hundreds, if not thousands, of dollars, to a vehicle’s price tag. Ford isn’t necessarily forcing the engines on consumers: An EcoBoost upgrade on the 2015 F-150 ranges between about US$800 (RM2870) to US$2,300 depending on the engine. Still, that’s cheaper than other fuel-saving technologies such as plug-in hybrids.
Ford produced more than 1.6 million EcoBoost engines globally in 2014, up more than 30 percent from 2013. More than 190,000 EcoBoost engines now are produced every month, up 90 percent from 2013. In 2014, annual global EcoBoost engine capacity reached approximately 2.3 million.
Aluminum — the current “buzz” material of the auto industry — is one way that turbocharger suppliers can reduce weight and increase efficiency. However, it gets much hotter than traditional steel turbochargers, and that can cause problems.
“You have to be able to thermodynamically handle the temperature coming out of the engine because turbos run very hot,” said Kregg Wiggins, Continental North America senior vice president of powertrain. “It’s always a trade-off in the vehicle: The higher the horsepower of the engine, the more heat you have to dissipate into the cooling system.”
Continental is producing a new turbocharger with an aluminum turbine housing that improves efficiency and lowers the part’s weight by 30 percent over its steel predecessor. It is the first time an aluminum housing has been used for a production turbocharger, according to company officials.
One of the most innovative technologies behind the aluminum turbocharger is how Continental manages its heat: Along with the double-walled aluminum housing, a cooling water jacket also surrounds the hottest area of the turbo. Coolant flowing through the jacket ensures that the external housing surface does not get hotter than 248 degrees and the internal temperature does not exceed 662 degrees.
Four-cylinder and smaller engines are expected to power the majority of vehicles produced this year in North America for the first time in modern automobile history, as automakers shift away from six- and eight-cylinder engines that a decade ago combined for more than 70 percent of the industry.
WardsAuto predicts 51.8 percent of new light-duty vehicles in North America to have four-cylinder engines. That’s up from less than 40 percent in 2010 and about 27 percent in 2005.
“The trend in downsizing is happening,” said Honeywell’s Kulkarni. “When you make smaller engines, the easiest way to restore power is turbocharging.”