1988 Acura Legend Audio System
The Legend music system delivers superior sound through careful matching of components to the vehicle. Development of the Legend LS version's Acura/Bose Music System was based on psychoacoustic principles formulated by Dr. Amar G. Bose, a MIT professor. Determination of the desired speaker location, for example, was aided with the use of life-size mannequins fitted with instruments that simulate human hearing. With this method it was possible to precisely locate and aim the speakers to achieve a desired frequency response over a broad volume range.
The Variable Intake Control System combines mechanical precision with electronic control. At low engine speeds, air passes through long (630mm) but relatively narrow (in cross section) rectangular ports. Their shape and dimensions create high intake air velocity and inertia, which increases volumetric efficiency and produces more torque for improved acceleration.
As engine speed increases, the engine's Electronic Control Unit (ECU) directs a solenoid actuator which opens six individual butterfly valves that allow air into short (420mm), oval, funnel-shaped ports - passing a greater volume of air into the combustion chambers. The transition from one set of ports to the other assures smooth power delivery throughout the full rpm range. Low to mid-range engine response is improved without sacrificing high end power. Torque is rated at 162 lbs-ft at 4500 rpm.
A sophisticated computer-controlled sequential fuel injection system helps develop the maximum engine power rating of 161 horsepower at 5900 rpm. An eight-bit microcomputer analyzes information from seven sensors (which monitor throttle angle, crankshaft angle, coolant temperature, manifold air pressure, atmospheric pressure and exhaust gas oxygen content) and uses the input to maintain the proportion of fuel and air within the ideal range. The ignition system is fully electronic.