2001 Acura Integra Type R -- Chassis
The Type R continues the enviable Integra tradition of providing a fully independent, 4-wheel double-wishbone suspension system for sporty handling. The Type R was developed with all-out performance in mind when it comes to cornering, braking and overall handling, and underwent some of the most rigorous racetrack testing ever conducted for a production automobile. The engineering team designed the Type R suspension to deliver highly responsive handling characteristics and provide the driver with high-quality feedback, excellent traction, high cornering limits, reduced body roll, and minimal understeer.
This was made possible in the Type R by:
- Reducing the ride height of the vehicle by 15 mm to lower the center of gravity
- Spring/shock combinations that offer a firm ride and precise handling
- Larger disc brakes with refined ABS modulator
- Increased body rigidity
- High-performance tires
The components of the front suspension are an L-shaped lower control arm, an upper control arm, a coil-over shock absorber, a stabilizer bar and a performance rod. The engineering team also specified the use of an aluminum shock tower bar to complement the 24 mm stabilizer bar that is equipped with ball joints instead of rubber bushings. The lightweight aluminum tower bar ties together the tops of the front damper housings. The performance rod is designed to act as an A-arm cross brace to stiffen the front lower subframe. The tower bar and performance rod are designed to enhance the rigidity of the suspension system to maximize handling and suspension precision.
The front suspension uses coil over, gas-pressurized damper assemblies fitted with the Honda Progressive Valve (HPV) unit for progressive damping action. The spring and damping rates have been greatly increased to improve performance handling. Front spring rate has been increased by 22 percent, with a 115 percent increase in compression damping, and a 70 percent increase in rebound damping. Additionally, the damper mounting bushing stiffness has been increased five-fold.
In order to enhance stability while braking in a straight line or 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 also 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 Type R tends to brake with maximum stability.
The rear double-wishbone suspension components consist of upper and lower control arms, a trailing arm, a coil-over shock absorber and a stabilizer bar. The road springs on the Type R have been changed from a straight-rate to a progressive-rate spring, increasing force across the entire range. Damping rates for the rear suspension have also been increased with compression damping settings in the progressive-valve unit increasing by 66 percent, and rebound damping going up 31 percent. The diameter of the stabilizer bar has been greatly increased from 13 mm to 22 mm to help reduce body roll. To enhance rear wheel stability, the bearing span within the rear-wheel hub has also been increased by 10 mm.
HIGH-RIGIDITY BRAKE CALIPERS AND ANTI-LOCK BRAKING SYSTEM
Like all Integra models, the Type R features 4-wheel disc brakes with ventilated rotors at the front and solid rotors at the rear. For better brake pedal feel and braking control and to provide a short pedal stroke, the front brake calipers are large, stout units that have a higher resistance to flexing and "spread" under severe braking conditions.
The Type R, with its larger brake discs (front: 262 mm to 282 mm; rear: 239 mm to 260 mm) and larger calipers, also uses a refined ABS system, which is 12.3 lbs lighter than the GS-R. This lightweight system functions with minimal pedal kickback during ABS operation in hard braking situations.
TORQUE-SENSING ROTARY VALVE STEERING GEAR
The Type R, like all Integras, features an innovative, torque-sensing rotary valve 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 when the steering wheel is turned. 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 effort with regard to lateral loads encountered while cornering.
WHEELS AND TIRES
The Type R is equipped with exclusive Bridgestone Potenza RE010 performance tires, similar to those found on the NSX, for greater cornering force, better response, and excellent road feel. These tires have been specifically developed to work in concert with the Type R's suspension calibrations, to provide excellent traction, stability, controllability and predictable handling behavior.
The Type R's exclusive aluminum wheels have a 5 mm greater offset than the GS-R. The 6.0 JJ x 15 alloy wheels also feature a large, five-bolt lug pattern for increased rigidity.