1999 Acura Integra-- Chassis

CHASSIS

OVERVIEW

The Integra continues in the enviable tradition of providing a fully independent, four-wheel double-wishbone suspension for a superb combination of sporty handling and excellent ride quality.

The objective was to provide the Integra driver with a vehicle that is responsive and comfortable in daily driving, yet with excellent cornering stability, good traction and stable behavior.

For 1999, the Integra features new 15 inch alloy wheels as standard equipment.

FRONT SUSPENSION

The components of the front suspension are an L-shaped lower control ann, an upper control arm, a coil-over shock absorber, a stabilizer bar and a performance rod. For the GS-R front suspension, the engineering team also specified the use of a shock tower bar and on the GS and the GS-R, a stabilizer bar equipped with ball joints instead of rubber bushings. The tower bar ties together the tops of the front spring/damper assemblies. The performance rod is signed to act as an A-arm cross brace to enhance handling and precision and stiffen the front lower subframe. The tower bar and perfonnance rod are designed to enhance rigidity and contribute to suspension precision.

In order to enhance stability under braking in both a straight line and while cornering, the L-shaped lower control arm has been equipped with specially tuned compliance bushings. These bushings allow the lower control arm to impart a toe-out condition on the front wheels. Allowing the wheels to toe out while braking in a corner enhances stability and allows the vehicle to track more precisely.

The engineering team has tailored the suspension to take the full benefit of negative scrub geometry, especially when braking on a split-friction surface. Under this condition, the suspension tends to maintain greater directional stability by countering the forces that would normally tend to steer the vehicle in the direction of the side with the lower traction coefficient. By balancing these forces, the Integra tends to brake with maximum stability.

REAR SUSPENSION

The rear double-wishbone suspension components consist of upper and lower control arms, a trailing arm, coil-over shock absorber and a stabilizer bar. All Integra models share the same rear suspension componentry and calibrations.

SUSPENSION TUNING

The engineering team designed the Integra suspension to deliver neutral handling characteristics and provide the driver with high-quality feedback and excellent traction. The spring/shock combination offers both a resilient ride and precise handling. Each shock absorber uses 30 mm cylinder and is equipped with an exclusive progressive valve unit, which opens progressively in response to wheel loads. Most shock valves are designed to either open completely or close completely in response to vertical wheel loads. This system provides better ride quality along with excellent handling.

HIGH-RIGIDITY BRAKE CALIPERS AND ANTILOCK BRAKE SYSTEM (ABS)

All Integra models feature four-wheel disc brakes, with ventilated rotors at the front and solid rotors at the rear. For maximum rigidity of the braking system and to provide a short pedal stroke, front brake calipers are large, stout units that have a higher resistance to flexing and "spread" under severe braking conditions.

The Integra uses a state-of-the-art ABS system to help the driver maintain steering control during hard braking. This lightweight system also functions with minimal pedal kickback during ABS operation.

TORQUE-SENSING ROTARY VALVE STEERING GEAR

The Integra features innovative, power-assisted steering gear design that is lighter and more compact than conventional power steering systems. Instead of modulating power assistance to the steering rack in accordance with road speed, this system varies power assist by a combination of engine rpm and the amount of torque generated between the pavement and the tire. The advantage of this system is that it exercises more precise control over the amount of power assist provided. It also provides more linear steering with regard to lateral loads encountered while cornering.

WHEELS AND TIRES

All models feature Michelin XGT-V4 195/55 R15 84V all-season performance radial tires mounted on lightweight 6.0 JJx15 machine-finished aluminum-alloy wheels. The tires have been specifically developed to work in concert with the suspension calibrations, to provide excellent traction, stability, controllability and predictable handling behavior.