1998 Acura Integra -- Structure
The goals for the Acura Integra structure were to provide a strong, rigid platform to ensure a long, durable service life, create a stable base for the suspension, provide carefully designed front and rear crumple zones to minimize cabin intrusion in a collision, and ensure very tight tolerances to help provide the occupants with a quiet, vibration-free environment.
Another goal was to shift as much of the mass to the center of the vehicle as possible to enhance transient response and handling. Other considerations included the creation of a large greenhouse to maximize front and rear visibility, creating a large cabin that provides ample room while making the cabin intimate to enhance the feeling of a sports-oriented coupe and sedan.
The styling of the 1998 Integra has been freshened in part by redesigning both the front and rear bumpers and combination lighting assemblies.
The aerodynamic goal for the Integra was to achieve a balance of forces that include moderate downforce at the rear, low turbulence, minimal wind roar in crucial areas such as the windows, excellent flow-through ventilation, and to provide optimum resistance to crosswinds while maintaining a low drag coefficient. This was achieved by extensive computer modeling, using the Cray supercomputer and wind-tunnel testing with scale models, mockups and prototype vehicle bodies. One important detail of the aerodynamic package is the one-piece, integral bumper assembly. This unit not only gives the Integra a clean, modern appearance, but its flowing, one-piece construction eliminates gaps between the bumper and the body that tend to produce turbulence and disrupt laminar airflow over the hood. The Integra has a drag coefficient of 0.33 and a lift coefficient of 0.10.
To enhance corrosion protection, virtually every panel of the Integra is constructed of double-sided galvanized steel. The only significant panel that does not use galvanized steel is the roof. After assembly, the body in white is treated to an electro-deposition process that bonds a rust-inhibiting primer coating to the metal. Electro-deposition draws this coating into minute crevices, helping to ensure a barrier against rust-producing moisture. A moisture-resistant wax is also injected into hidden body cavities, to help prevent corrosion that might otherwise form from condensation.
Rigidity clearly has an impact on a number of critical areas. Any suspension, for instance, no matter how finely calibrated or advanced in design, will fail to perform properly if the body flexes and bends under loading. Rigidity also contributes significantly to crash protection and reduction of vibration and exterior noise, and to the build quality perceived in areas like the small gaps between panels and openings.
Developed using the latest computer modeling and Finite Element Analysis techniques, the current Integra Sports Coupe is 40% stiffer in bending and 20% stiffer in torsional rigidity than the previous model. The Sports Sedan is 50% stiffer in bending and 5% stiffer in torsional rigidity.
To update the styling of the 1998 Integra, the fully integrated bumper and lighting has been re-styled while maintaining the unique signature of the 4-headlight design.
The use of a one-piece integral front bumper accomplishes a number of objectives. In addition to providing a clean, modern and aerodynamic appearance, it reduces the number of components and the weight of the front facias, enhances the anti-corrosion performance of the entire front end, resists minor dents and flying debris better and, in case of a minor collision, helps reduce damage that might otherwise be transmitted to the front fenders.
The choice of polypropylene for front and rear bumper material was made based on its properties of resilience to minor damage and because of the material's inherent recyclability. Due to the unique formulation of pigments and medium, the painted bumper resists the fading that was commonly associated with synthetic plastic bumpers. The front and rear bumpers of the Integra resist damage up to a 5-mph collision.
One of the design priorities of the body was to provide the driver with as much visibility as possible. As a result of extensive engineering, which was able to create thin but strong pillars, and a compact engine, which contributes to a low cowl, the Sports Coupe offers 298.9 degrees of visibility while the Sports Sedan offers 306.3 degrees of visibility.
PIN-GUIDE DOOR SASH
The Integra Sports Coupe uses a pin-guide sash system for the door glass. A pin, which is bonded to the rear inside edge of the door glass, slides in a channel designed into the window sash. The pin holds the window captive against the sash and forms a tight seal to enhance the rigidity of the glass and resist the negative air pressure that builds up at the side of the vehicle at high road speeds. The system also allows tighter tolerances between the glass and the moulding, and contributes to better aerodynamics and reduced levels of wind noise.
In order to maximize head room, the Integra LS, GS and GS-R Sports Coupes and Sports Sedans feature a moonroof that slides back and out of the roof proper. Unlike conventional sunroof configurations that slide into a receptacle in the roof, this unit takes up less head room.
PROJECTOR BEAM HEADLIGHTS
A key element of the 1998 Integra styling is the signature four-headlight design. For 1998, the individual lights have been enlarged and repositioned for a near-flush look. This change not only improves styling, it helps smooth aerodynamic flow over the front bumper.
To enhance illumination and give the Integra a modern look, the engineers specified projector beam lamps for low-beam use. Compared to conventional units, these lamps reach 13 feet farther and illuminate an area 20% while the high beams, which use improved halogen lamp technology, reach 125 feet farther and illuminate an area 2.5 times greater.
As mentioned earlier, the Integra provides a high degree of structural rigidity to enhance crash protection. At the front and rear, the Integra has been designed with deformable crumple zones. These are designed to deform in a controlled manner, absorb the impact energy and help prevent deformation of the passenger compartment.
To help minimize injury to the occupant in a side-impact collision, the Integra features door intrusion beams as well as energy-absorbing pads in the doors.
On the Sports Sedan, there is a polypropylene pad located at hip level and a extended styrene pad located at shoulder level for both front and rear doors. The Sports Coupe, due to its different structural architecture, requires only a polypropylene pad. These pads substantially reduce the energy transmitted to the occupants in the event of an accident.