VarioRam is a

Porsche Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche (; see #Pronunciation, below), is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans, headquartered in Stuttgart, Baden-Württemberg, Germany ...

-patented engine induction system that was first introduced on the 1992 model year

964 Year 964 ( CMLXIV) was a leap year starting on Friday (link will display the full calendar) of the Julian calendar. Events Byzantine Empire * Arab–Byzantine War: Emperor Nikephoros II continues the reconquest of south-eastern Anatoli ...

Carrera RS motorsport special. It became standard on the 911-series starting from the M64/21 engine on the model year 1996. As the name suggests, VarioRam varies the effective length of the inlet ducting depending upon engine load and speed. A long intake length at low rpm provides a better pulse tune because the pulse won't travel back and forth as many times, which aids low-end

torque In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...

because the high pressure pulse may otherwise contribute to reversion and thereby decreased volumetric efficiency. At higher engine rpm, the intake length is reduced. The result is a flatter torque curve, with more torque available at low- and mid-range engine speeds compared to a similar non-VarioRam engine.

References

{{Porsche vehicles Porsche Engine technology