There are two main effects of variable intake geometry:
Swirl - Variable geometry can create a beneficial air swirl pattern in the combustion chamber. The swirls help distribute the fuel and form a homogeneous air-fuel mixture which ignites without engine knocking. At low rpm, the speed of the airflow is increased by directing the air through a longer path with limited capacity (i.e., cross-sectional area), but the shorter and larger path opens when the load increases so that a greater amount of air can enter the chamber. In DOHC designs, the air paths are often connected to separate intake valves so the shorter path can be excluded by de-activating the intake valve itself.
Pressurization - A tuned intake path can have a light pressurizing effect similar to a low-pressure supercharger due to Helmholtz resonance. However, this effect occurs only over a narrow engine speed band. A variable intake can create two or more pressurized "hot spots", increasing engine output.
Many automobile manufacturers use similar technology with different names. Another common term for this technology is Variable Resonance Induction System (VRIS). A combustion chamber is part of an engine in which fuel is burned. ... Ignition occurs when the heat produced by a reaction becomes sufficient to sustain the reaction, whether it be a fire, an explosion, or nuclear fusion. ... Knocking (also called pinking or pinging)— colloquially detonation—in internal combustion engines occurs when air/fuel mixture in the cylinder has been ignited by the spark plug and the smooth burning is interrupted by the unburned mixture in the combustion chamber exploding before the flame front can reach it. ... rpm or RPM may mean: revolutions per minute RPM Package Manager (originally called Red Hat Package Manager) RPM (movie) RPM (band), a Brazilian rock band RPM (magazine), a former Canadian music industry magazine In firearms, Rounds Per Minute: how many shots an automatic weapon can fire in one minute On... A double overhead cam (also called a dual overhead cam, DOHC, or twincam) engine is a type of internal combustion engine where the camshafts that operate the intake and exhaust valves are mounted above the cylinders, and where there are separate camshafts for inlet and exhaust valves. ... A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. ... Engine tuning or engine building is the adjustment, modification or design of internal combustion engines to yield more performance, either in terms of power output or economy. ... A supercharger (also known as a blower) is an air compressor used to force more air (and hence more oxygen) into the combustion chamber(s) of an internal combustion engine than can be achieved at ambient atmospheric pressure. ... A brass, spherical Helmholtz resonator based on his original design, from around 1890-1900. ...
Audi - 2.8-liter V6 gas engine (1991-98); 3.6 and 4.2 liter V8 engines, 1987-present
FordDSI (Dual-Stage Intake) - on their Duratec 2.5 and 3.0 liter V6s and it was also found on the Yamaha V6 in the Taurus SHO.
Ford - The Ford Modular V8 engines sport either the Intake Manifold Runner Control (IMRC) for 4V engines, or the Charge Motion Control Valve (CMCV) for 3V engines.
MazdaVICS (Variable Intake Control System) is used in the Mazda B engine family of straight-4, and VRIS (Variable Resistance Induction System) in the Mazda K engine family of V6 engines. An updated version of this technology is employed on the new Mazda Z engine, which is also used by Ford as the Duratec.
Opel (or Vauxhall) TwinPort - modern versions of Ecotec Family 1 and Ecotec Family 0 straight-4 engines; a similar technology is used in 3.2 L 54° V6 engine
Volvo - VVIS (Volvo Variable Induction System) Volvo_B52_engine as found on the Volvo_850 and S70/V70 vehicles, and their successors. Longer inlet ducts used between 1500 and 4100 RPM at 80% load or higher. [1]
The intakemanifold of claim 1 further including a plurality of base sections mounted to the runner shaft between the runner blades that, together with the corresponding runner blades and the upper surface portion of the manifold housing, define runner passages, one each to a respective one of the outlet passages.
The intakemanifold of claim 5 wherein the one of the plurality of runner blades is extendible circumferentially into the divider by an angle.phi..sub.0, and the runner shaft is rotatable by an angle greater than.phi..sub.0 to selectively allow flow between the two sections of the variable plenum.
The intakemanifold of claim 1 wherein the one of the plurality of runner blades is extendible circumferentially into the divider by an angle.phi..sub.0, and the runner shaft is rotatable by an angle greater than.phi..sub.0 to selectively allow flow between the two sections of the variable plenum.
Compared to rigid intake systems, whose geometric configuration of intakemanifoldlengths, pipe diameters, or container capacities represents a compromise with respect to the location and magnitude of the maximum torque or power, the full-load characteristics may be optimized by expanding the variability.
The principle of variableintake systems is based, among other factors, on the fact that sympathetic oscillations, for example, are generated in the air mass that is drawn into the intakemanifold.
Errors occurring in the regulating unit for the intakemanifold geometry of the intake system are detected by comparing the signals in the error case (erroneous signals detected) with signals in the error-free case (reference or setpoint variables).
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