Un article concernant le 1.0 kappa turbo sur le site:
http://www.motoring.com.au/news/2011/sm ... iple-23879
Kia's Kappa Turbo Triple
New three-cylinder engine takes fuel-saving technology into the low, low end of the market - without sacrificing performance
Kia's Kappa engine family has spawned a 1.0-litre turbocharged three-cylinder engine to heal the rift between performance and fuel efficiency.
It's part of the company's strategy (and that too of parent company Hyundai) to provide engines that will deliver strong performance for the displacement, but still meet consumer and legislative demands for more fuel-efficient drivetrains. Other companies have also embarked on this path -- not least of all Volkswagen -- but what makes Kia's Kappa development unique is the size of the engine, its three-cylinder inline layout and some of the sophisticated technology it brings to the affordable end of the market.
During the Geneva motor show, where the engine made its public debut, Doctor Joachim Hahn, Kia's Manager for Powertrain Engineering in Europe, sat with journalists from Australia to explain the whys and wherefores of the new engine.
"[The Kappa] is one of the engines installed in the new Picanto," he explained. "The Kappa engine family is already successful... So far it's a four-cylinder -- a 1.2-litre engine -- and now we have introduced the all-new three-cylinder engine with 1.0-litre displacement.
"For this displacement class we introduced new technologies. For example, this is the first 1.0-litre engine that is equipped with dual CVVT, which means that for intake as well as exhaust we have continuous variable valve timing. That is clearly one of our strategies to downsize the engines.
"Of course we cannot forget about the 'fun to drive' [philosophy]. The customer will not accept any lack of power or any lack of torque. That has to be fulfilled: Smaller engines with the intention of fuel consumption reduction, but in combination with [on-going] powerful [performance]."
The 998cc engine develops its peak torque of 137Nm from as low as 1500rpm, across a plateau up to 4500rpm. While we can't yet assess how the 81kW powerplant performs in the real world, Kia claims it's very driveable and highly responsive to throttle input. In addition to the turbocharging and the variable valve timing facilities, the engine boasts a variable intake system.
On the fuel efficiency side of the ledger, the three-cylinder Kappa introduces DLC ('Diamond-Like Carbon') coating for the tappets to reduce friction. Other innovations include progressive-rate valve springs, low-friction piston rings and an offset crankshaft to reduce the horizontal forces on the crown of the piston leading to a subsequent power loss. According to the company, these changes -- and others such as the turbocharging and optimised CVVT -- reduce fuel consumption by an amount in the vicinity of 8.8 per cent.
The engine features an aluminium block with cast-iron liners, which is one method of saving weight; others including the integration of cylinder head with air filter, the engine-support bracket with timing chain cover and exhaust manifold with turbocharger. In the case of the last, according to Doctor Hahn (pictured with a cut-away Kappa), the positioning of the turbocharger helps "light-off" for the catalytic converter to warm up faster and reduce pollutants reaching the atmosphere immediately following cold starts.
Intended to be introduced to the Kia model range powering the Picanto from June 2012, the engine has been developed with buyer expectations in mind. As Doctor Hahn explained, the technology must be "reasonable" for the car and its consumers. There's no point developing seriously high-tech solutions that place the car in a whole new price bracket and make it unaffordable for its target demographic.
"When we talk about the new Picanto, we have to be aware of the fact that we're talking about 'A segment'," he said. "A Segment is -- even more than all the other segments -- very cost-sensitive. If we introduce any new technology, we have to think [whether] the customer is willing to pay money for it.
"That was exactly the reason we decided to develop a three-cylinder engine with... 'reasonable' technology
