Friday, September 16, 2011

Mazda set to unveil Skyactiv technology

 

Greater torque? Increased fuel economy? Yes, please!

“Mazda has often thought outside of the box when it comes to power.

Consider its adaptation of the Wankel rotary engine. Designed by German engineer Felix Wankel, Mazda began experimenting with Wankel-style rotary engines in 1961, finally offering a rotary equipped vehicle in 1967.

Throughout the 1970s and 1980s Mazda stuck with the more conventional internal combustion piston engine in the bulk of its vehicles, but it did continue with the rotary in the legendary RX-7 sports car. By 1993, in Canada the rotary-powered RX-7 had been dropped, but the company came back in 2003 with the Renesis rotary in the RX-8.

As mentioned, though, the bulk of Mazda's powerplants were and still are internal combustion piston units - and will continue to be for the foreseeable future.

However, Mazda has been hard at work developing a more efficient kind of internal combustion engine. What it has arrived at is its brand new Skyactiv technology.

According to Mazda, even though the internal combustion engine has been undergoing constant development for more than 120 years, the units are ineffectively using a large amount of the volatile energy found in fuel.

In a recently published technology paper regarding the new Skyactiv technology, Mazda wrote that most of the energy loss in an internal combustion engine is primarily thermal in nature. The losses could be attributed to the exhaust, cooling system, and engine and transmission surfaces.

To rectify the situation, Mazda's research and development team focused on improving the engine's thermal efficiency, and also worked to reduce internal engine friction and overall weight.

Mazda set out to optimize six engine factors, including compression ratio, air-to-fuel ratio and combustion timing. Mazda decided that compression ratio would be the most important factor of all - and with Skyactiv developed an engine to run with a much higher 14: 1 compression ratio (in North America, where it has been tuned to run on 87 octane fuel, it's 13: 1) than would normally be found in an everyday automobile.

How Mazda has effectively engineered a high-compression engine intended for the daily grind becomes a slightly technical discussion. Basically, Mazda reduced combustion duration, reduced weight and internal engine friction and designed pistons with special crowns.

Those initiatives, together with an intriguing new 4-2-1 exhaust manifold designed to quickly move hot waste gases away from the engine - preventing it from being forced back into the combustion chamber - greatly increase thermal efficiency.

What does this mean for drivers? There will be greater torque over a wide range of revs, and fuel economy should improve by 15 per cent.

In the technology paper, Mazda Motor Corporation's executive vice-president Seita Kanai said: "Our mass production development division worked together to engineer the best possible architecture with incredible efficiency, dramatic performance and the best quality we've ever had.

"We could then, for example, make the cylinder larger, smaller, multiply it by three, four, six, etc. (and) create a range of engines for any future application."

In Canada, the newest Skyactiv-G (G is for gasoline, there is also a D for a diesel) engine will debut in the refreshed 2012 Mazda3, arriving here in October.

Mazda has designed all new lightweight bodies and chassis to accommodate the new and larger 4-2-1 manifold, but in the 2012 Mazda3, the Skyactiv-G engine will only have a compression ratio of 12: 1 - and not the touted 13: 1.

Mazda Canada's national manager of public relations Sandra Lemaitre said in an e-mail to me: "The reason for this is due to packaging constraints on the exhaust manifold when this engine is used in the Mazda3 legacy platform (and not with the new Skyactiv body and chassis).

"The 2012 Mazda3 will have the Skyactiv-G 2.0-litre gasoline engine with the Skyactiv-Drive six-speed automatic transmission (or) the Skyactiv-MT six-speed manual transmission mounted onto a current vehicle platform in order to make Mazda's latest technologies available to customers as quickly as possible."

The next vehicle to get Skyactiv will be the all-new 2013 CX-5, which will be launched in the first quarter of 2012. Lemaitre confirmed the Mazda CX-5 will be the first of Mazda's new generation of vehicles to adopt the full range of Skyactiv technologies, including the new platform.”

Read more: http://www.calgaryherald.com/cars/Mazda+unveil+Skyactiv+technology/5411921/story.html#ixzz1Y9A4LXXk

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