Quote:
Originally Posted by serialk11r
Yup. Ferrari could actually get pretty close to MultiAir performance efficiency-wise if they were willing to change the torque curve a bit; Extend the duration on the low rpm part and use that to cut pumping losses.
I'm quite surprised that MultiAir is a fully functional production system; actively controlling all those valves is one of those things that seems like it could get very complicated, and they had to figure out how to damp the valves in the case that they release oil pressure when the spring is loaded.
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If you think MultiAir is complicated, you should study other continuously variable valve lift systems. The beauty of MultiAir is the simplicity of the hardware. There's no cam phaser and there's only one cam shaft. There's no electric motor, no worm gear set, no crazy moving links and extra shafts. It's just a few solenoids with hydraulics, some followers, and conventional exhaust valve actuation. Look at complexity of Nissan and Hyundai's systems and you'll see what I'm saying about how simple MultiAir really is.
Also, MultiAir is actually UniAir by the Schaeffler group. It's a German technology. See this paper by them:
https://docs.google.com/file/d/0B_jE...it?usp=sharing . It explains how the braking function of the valve and how energy is transferred through the system.
