Porsche Research and Development approached DuPont to address an air intake manifold noise harshness problem at the 2.5 liter water-cooled Boxster flat six engine. The noise harshness problem was found to occur as the variable camshaft timing switched from torque to power mode at 2250 rpm. The harsh noise was caused by an air pulsation problem within the plenum chamber due to an increase in the inlet/exhaust valve overlap, during the power mode of the variable camshaft timing. The method chosen for modification was to thicken the whole of the upper surface of the plenum chamber by 1.5 mm. This reduced the resonant peak at 730Hz and the resonant peak at 900 Hz.
Noise optimization of plastic air intake manifolds
Plastics Components, Processes, and Technology, 1998, SAE International Congress & Exposition, 1998 ; 1-5
SAE-SP (Special Publications) ; 1340 , Feb
1998
5 Seiten
Conference paper
English
Noise optimization of plastic air intake manifolds
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