1999 Acura CL- Chassis
The CL is equipped with a 4-wheel, independent double-wishbone suspension with coil springs and front and rear stabilizer bars. The suspension has been designed to provide excellent directional stability and the tight, precise handling control demanded by driving enthusiasts, yet with a forgiving and resilient ride. Helping to achieve those goals are a highly rigid body structure and a 16-inch wheel and tire package specially developed to meet the chassis team's requirements of handling grip, ride poise and quiet operation.
Other chassis features include 4-wheel disc brakes, a standard Antilock Braking System (ABS) and a speed-sensitive variable power-assisted, rotary-valve, rack-and-pinion steering system.
Redesigned alloy wheels with a bright machined finish help highlight the 1999 3.0CL.
The front double-wishbone suspension consists of a leading compliance link, an upper transverse A-arm and a single lower transverse link. The leading link provides fore-aft location for the wheel and transmits braking and acceleration forces to the body. A rubber bushing at the anchor point of the link helps absorb impact energy. A long curved upright connects the links to the hub assembly. On the 3.0CL, the front suspension is mounted to a rubber-isolated subframe for improved NVH and refinement.
To minimize body roll, the CL is equipped with a front stabilizer bar. The hollow bar on the 2.3CL has a diameter of 27.2 mm with a 3.0 mm wall thickness; the 3.0CL uses a solid 25 mm bar.
The front shock absorbers are nitrogen gas-pressurized and fitted with a patented "New Wide Setting" (NWS) progressive-valve system. This valve uses special layered disk plates to control the fluid flow, rather than a fixed orifice. By using the NWS valve, the suspension engineers were able to tune the damping force precisely to achieve a fine balance of responsive handling and smooth ride quality.
The rear double-wishbone suspension consists of a beam-type leading link for fore-and aft wheel location, a single upper transverse link for lateral location and a pair of lower unequal-length transverse links. The unequal length of the lower links acts to steer the rear wheels in such a way that it cancels the roll-steer effect inherent in independent rear suspensions. This helps the CL track smoothly through comers, respond predictably in transient maneuvers such as lane changes and exhibit less susceptibility to crosswinds.
The CL features a liquid-filled bushing at the pivot point of the rear suspension trailing link to isolate the passenger cabin from road noise. A rigid rear hub bearing provides high toe stiffness, delivering excellent stability at high speeds.
Both the 2.3CL and the 3.0CL use a solid, 16 mm rear stabilizer bar. As in front, the rear suspension incorporates a NWS progressive-valve system in the damper units.
Steering-Effort-Sensitive, Variable Power-Assisted, Rotary-Valve, Rack-And-Pinion Steering System
The rack-and-pinion power-steering system on the CL is torque-sensitive. The system varies power assist by monitoring the amount of torque generated between the tire and the pavement as the steering wheel is turned. An increase in effort (for instance, if a wheel were to encounter a surface with a greater coefficient of friction) is automatically countered by an increase in boost.
The power steering rack uses a rotary valve and torsion bar. The torsion bar twists in proportion to steering effort. As it twists, it progressively opens a hydraulic valve that increases boost accordingly. An additional advantage of this design is greatly reduced power-steering noise, backlash and kickback.
To minimize the noise and vibration transmitted to the body and passenger compartment, the upper part of the steering shaft is hollow. In addition, the shaft is mounted in a stiff, anti-resonant bracket.
A quiet, vane-type, rotary power steering pump provides hydraulic pressure. The vanes create a smaller pressure fluctuation and the pump body incorporates a flow control valve that supplies a constant pressure. A pressed steel drive pulley helps reduce weight.
The system is tuned to provide light, effortless steering during parking, yet provides excellent road feel at higher speeds.
Braking is provided by a power-assisted,4-wheel disc braking system. Large, flex-resistant calipers help provide consistent braking performance. The front rotors are internally ventilated to aid in rapid heat dissipation. For the 2.3CL, front and rear rotor dimensions are 260 mm x 23 mm and 260 mm x 10 mm, respectively. The 3.0CL employs 282 mm x 25 mm front rotors, and 260 mm x 10 mm rear rotors.
In keeping with the CL's sporting demeanor, high friction brake pads help provide superior resistance to fade, along with the solid, positive brake-pedal feel preferred by driving enthusiasts.
Antilock Braking System (ABS)
The standard Antilock Braking System (ABS) features four wheel-speed sensors and three channels. The system exercises independent control over each of the front wheels, while controlling the rear wheels as a single unit. This is a "select-low" system, meaning the system controls both rear wheel calipers together when it senses impending wheel lockup in either wheel.
In the unlikely event of a system failure, the main hydraulic system remains operational, including the dual-diagonal feature and the front-to-rear proportioning bias.
The ABS modulator unit is designed to have very little pedal kickback when operating. The modulator unit incorporates the high-pressure accumulator.
Wheels And Tires
To reduce unsprung weight and provide a fine balance of ride and handling, the CL is equipped with machine-finished cast aluminum alloy wheels fitted with specially developed Michelin MXV4tires in P205/55 R16 size. Wheel size is 16 inches x 6 inches.