| The legendary ingenuity of Porsche is plainly evident in the patented VarioCam variable valve technology. In the simplest terms, VarioCam continually adjusts the intake valve timing to enhance the performance of the Cayenne in all drinving situations. In reality, it's a bit more involved.
Operating under direct control of the Motronic engine management system, VarioCam uses a rotary-vane actuator on each bank of cylinders to continually adjust the phase angle of the intake cam. To improve throttle response after starting in cold weather, VarioCam retards valve timing. At medium revs, and when the engine is under minimal load, the system advances valve timing to minimize fuel comsuption and exhaust emissions. For maximum thrust at higher revs, VarioCam advances valve timing. Another important feature of the VarioCam is hydraulic valve adjustment. In addition to reducing engine noise, this technical feature helps minimize emissions during warm-up. Plus, there's no need for regular valve adjustment. |
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