Honda Insight -- Chassis
Design goals for the Insight's chassis centered around achieving sporty~ responsive handling, good ride characteristics and world-class safety, all while contributing to the overall goal of reaching the highest fuel efficiency possible. To meet this challenge, Honda engineers developed an innovative new chassis design that takes advantage of the high strength-to-weight properties of aluminum and plastic.
TECHNICAL INNOVATIONS FOUND IN THE HONDA INSIGHT CHASSIS
- Rigid aluminum body forms a strong, stable suspension platform
- Forged-aluminum front suspension arm and steering knuckle
- Hollow front-strut damper rod saves weight
- High-mounted, center-pivot electric power steering (EPS) is compact and efficient
- Forged-aluminum tie rods
- Lightweight aluminum-alloy wheels
- Aluminum-alloy rear brake drums and front brake calipers
- Compact twist-beam rear suspension sits under cargo floor
- Aluminum engine mounts
- Lightweight exhaust system
- Plastic-resin fuel tank
- Low-rolling-resistance all-season tires
ALUMINUM-ALLOY FRONT SUSPSENSION
The Insight's front independent suspension uses a strut-type spring/damper unit at each wheel. To save weight, the strut's damper rod is hollow. Additional unsprung weight is saved by the use of a lightweight forged-aluminum steering knuckle and a forged-aluminum lower suspension arm. The system is also very compact -- both of the lower arm's inner pickup points are connected to the same reinforced, cast-aluminum mounting.
The wheel is also a lightweight aluminum casting. A O.66-in.-diameter stabilizer bar links the front wheels.
The front suspension geometry has been optimized to exhibit mini-mal changes in toe and camber throughout its travel, giving the Insight responsive handling, excellent stability and a smooth ride.
COMPACT TWIST-BEAM REAR SUSPENSION
The Insight's rear suspension consists of twin trailing arms interconnected by a curved, flattened beam (called a twist beam) midway along their length. The twist beam is open along one side, soit will twist in response to the movement of the trailing arms and function as an anti-roll bar (stabilizer bar). The Insight's twist-beam rear suspension system is very compact, and, along with a 10.6-gallon, plastic-resin fuel tank and spare-tire compartment, sits entirely below the cargo area floor. Coil springs are used, and the system's telescopic shock absorbers are mounted at a separate location, which also contributes to the Insight's flat cargo floor.
Large rubber bushings, built into the trailing-arm pivots, provide bump compliance, as well as enhanced stability via toe control when cornering. The trailing arms and interconnecting twist beam are made of steel.
The Insight features specially designed 165/65 R14 78S mud- and snow-rated low-rolling-resistance tires, mounted on 14 X 5.5 jj aluminum-alloy wheels. These new tires have 40 percent less rolling resistance than conventional tires and a 5-percent reduction in weight.
HIGH-MOUNTED ELECTRIC POWER STEERING SYSTEM
The Insight uses an innovative high-mounted rack-and-pinion steering system, assisted by an electric motor, called EPS (electric power steering). EPS offers numerous advantages over conventional hydraulically assisted steering systems: it is simpler and more compact (there is no need for a hydraulic pump and hoses), and the power loss is minimized. The system's compactness and simplicity offer more design freedom in terms of placement within the chassis, and it is also smoother operating, more responsive to driver input, and has minimal steering kickback. The overall steering ratio is 16.4 to 1, and 3.32 turns lock-to-lock.
The system consists of a toothed rack-and-pinion gear, with a microprocessor-controlled, coaxial electric motor assisting the pinion. The micropwcessor senses vehicle speed and steering torque and is programmed to vary boost accordingly, providing more boost at low speeds and progressively less at higher speeds so that the system has a sporty. responsive feel. Failure warning, self-diagnosis and self-protection functions are also built into the EPS system.
An innovative feature of the Insight's EPS system is its high mounting location: The steering rack, electric drive and forged-aluminum tie rods are all mounted high on the bulkhead, and steer the wheels via steering links on each front suspension strut. This location was chosen in order to achieve a more compact engine compartment.
ALUMINUM BRAKE COMPONENTS
In the interest of reducing overall vehicle weight, Honda engineers specified front brake calipers and rear brake drums made of aluminum (these components are usually made of iron). Like the rest of the suspension's aluminum components, these lightweight pieces also help to enhance vehicle handling and ride quality.
LIGHTWEIGHT EXHAUST SYSTEM
The Insight's exhaust system incorporates several weight- and space-saving measures made possible by the IMA engine's reduced size. For example, smaller-diameter, thinner gauge pipe is used, thereby saving the weight that would be required for a larger engine. In addition, the system's smaller weight and the elimination of the exhaust header (the header is now integral with the cylinder head) allowed it to be constructed as a single unit, thus eliminating the additional weight of interconnecting exhaust flanges.
ALUMINUM ENGINE MOUNTS
The Insight IMA engine uses lightweight aluminum-alloy engine mounting brackets that incorporate hydraulic (liquid-filled) mounts that help damp engine vibration. The mounts are located on the axis of the engine's principal inertial moment (the axes about which the engine vibrates). At these points, the least amplitude of engine vibration is transmitted from engine to frame, which significantly reduces engine-idle vibration.
PLASTIC-RESIN FUEL TANK
The Insight's 10.6-gallon fuel tank is made of strong, lightweight plastic resin, instead of the more commonly used stamped and welded steel.