A few years ago, automotive technology looked as if it was headed for the drag strip. Consumers, weary of an emphasis on fuel economy, welcomed vehicles that were bigger, faster, and more fun.
Now, that's changing. In 1997, automotive innovation takes a decidedly utilitarian turn. With a few exceptions, engineers are spending less time squeezing a few extra horsepower from their engines, and more time stiffening their frames and chassis for safety's sake. Part of that, of course, is by government mandate. In 1997, new side-impact regulations take effect. But another part is customer demand. Today's auto buyers are looking for quality like never before, and they're defining it as quieter, safer, more durable, better handling automobiles. Automakers are meeting that demand by adding steel door beams, cross-car reinforcement, and heavier front frame rails. Almost every nameplate now offers standard driver-side airbags. And many automakers now incorporate passenger airbags and side airbags.
That's not to say there are no engine innovations. Ford, for example, is introducing a new SPI (Split Port Induction) 2000 engine, Jaguar has a new V-8, and General Motors is unveiling the third generation of the famed small-block V-8.
Still, it's the emphasis on quality that characterizes the 1997 offerings overall. Here are the most important automotive-technology developments coming from the U.S., Europe, and Asia, as uncovered by Design News editors.
- SPLIT PORT INDUCTION(SPI) 2000 ENGINE. "The camshaft is the only carry-over part from the original 1.9-l engine," says Ford spokesman Rick Titus of the new 2-l 4-cylinder engine the company calls the SPI 2000. Ford's implementation of split-port-induction (SPI) technology, it powers the '97 Ford Escort and Mercury Tracer, delivering 110 hp at 5,000 rpm and 125 lb-ft of torque at 3,750. Power increases by 25%, with an accompanying increase in fuel efficiency. The aluminum cylinder head has one intake and one exhaust valve per cylinder. The intake port is split into two intake runners for each cylinder: one for low speed (high swirl) and the other for high-speed operation. An electronically controlled butterfly valve for each cylinder regulates air flow through the high-speed runner. Above 3,000 rpm, the butterfly valve opens, increasing airflow for additional power.
- LIGHTWEIGHT VALVE TRAIN. A new lighter-weight valve train reduces noise and vibration and improves economy of Ford's SPI 2000 engine. Conically shaped valve springs permit use of smaller, lighter valve-train components. An automatic cam belt tensioner for the overhead camshaft compensates for expansion and contraction of engine parts at different temperatures. It increases belt life and reduces noise and vibration with consistent tensioning. The 44-mm intake and 37-mm exhaust valves are larger than their predecessors, and improve high-rpm performance.
- LOW-EMISSION ENGINE. After its complete redesign in 1996, America's best-selling car, Ford Taurus, attains low-emission vehicle (LEV) status with its 3.0-l Vulcan overhead 24-valve V-6 with revised catalytic configuration. Engine recalibration and a secondary air-injection system enable the Taurus to qualify as a transitional low-emission vehicle (TLEV) in states considering more stringent emissions standards. The 3.0-l Vulcan-equipped Taurus also offers two flexible fuel packages, first introduced in mid-1996. One, available for models sold in 50 states and Canada, permits up to 85% ethanol in its fuel.
- 3.4-l 60-DEGREE V-8. The SHO sports sedan, a mid-1996 entry, is powered by an all new 3.4-l60-degree V-8 engine. The first V-8 offered in a Taurus, it is rated at 235 hp at 6,100 rpm and 230 lb-ft of torque at 4800 rpm. The DOHC 32-valve aluminum block engine is the first Ford engine to use coil-on-plug ignition, which allows engine designers more flexibility in engine calibration. Plugs can be fired multiple times during each firing cycle to help maximize combustion efficiency and fuel economy, prevent spark-plug fouling, improve idle, and reduce emissions. The SHO V-8 is Ford's only engine that has reverse-flow cooling. Cylinder heads receive coolant first, then the coolant flows through the engine block and back to the radiator. The result: cooler cylinder heads, and improved fuel efficiency.
- NEW 4.6- AND 5.8-l ENGINES. Ford's new Triton 4.6-l and 5.8-l engines share a common design and most features. Both are chain-driven, single overhead cam (SOHC) engines with reinforced blocks and tuned intakes. Both have deep-skirt blocks, cross-bolted main bearing caps tied directly to the deep skirt, deep-mounted cylinder head bolts, improved bore roundness and three-layer steel head gaskets. Ford included these features to reduce noise, vibration, and harshness (NVH) characteristics and cut friction and oil consumption. In the F-series pick ups, the 4.6-l delivers 220 hp at 4,500 rpm and a torque of 290 lb-ft at 3,250 rpm. The 5.8-l delivers 235 hp at 4,250 rpm and 330 lb-ft at 3,000 rpm. The 5.4-l increases its displacement by employing a longer stroke than the 4.6-l. The block has a raised deck to accommodate its longer stroke. A steel crankshaft with induction-hardened pins and mains increased engine durability.
- FAIL-SAFE COOLING SYSTEM. Each Ford Triton engine has a fail-safe cooling system designed to help protect against damage from overheating, while giving drivers additional time to get to a service station. If the vehicle loses coolant, a sensor in the cylinder head monitors the cylinder head's rise in temperature. The computer alternates firing in the cylinders, allowing half of them to pump only air to cool the engine. The system allows the vehicle to be driven a short distance with limited power before incremental component damage occurs. The distance depends on ambient temperatures, vehicle load, and road conditions. A "check engine" light and temperature gauge registering "hot" warn the driver of the need for immediate service. The engine will run on alternate sets of cylinders, allowing one set to cool off before switching back to it. If temperatures exceed a certain preset level, the computer shuts down the engine to prevent engine failure. The lubrication system has a six-quart-capacity oil pan to help reduce engine temperatures and provide additional lubrication.
- TRITON V-10. The Ford Triton 6.8-l V-10 is based on the 5.4-l V-8. Both have identical bores, but the V-10 has a longer stroke than the 4.6-l V-8. The Triton V-10 has evenly spaced firing pulses and a balance shaft to maximize smoothness. Like the other engines in the Triton family, the V-10 has a deep-skirt block design, with deep-mounted cylinder head bolts for improved bore geometry, better oil economy, and reduced friction. The deep-skirt block design also improves powertrain stiffness, which reduces noise in the passenger compartment. It employs multiport fuel injection and Ford's fifth-generation EEC-V electronic engine-control module for maximum power, fuel economy, and emissions control. Larger water-pump impellers, larger aluminum radiator, and upgraded fans and clutches improve cooling-system efficiency. The engine produces 265 hp at 4,250 rpm and 410 lb-ft at 2,750 rpm.
- 5.9-l, OHV, IN-LINE SIX-CYLINDER DIESEL ENGINE. Chrysler engineers have modified the throttle control system for the '97 Ram Pickup. The old system had limited throttle travel due to injection pump variations. The redesigned throttle control system is more durable and enables full throttle capability under all conditions. It includes redesigned primary and secondary bell cranks, throttle lever, and throttle cable.
- STRUCTURAL OIL PAN AND ENGINE/TRANSMISSION COLLAR. A redesigned structural cast-aluminum oil pan stiffens the lower engine block on Chrysler's 2.4-l, DOHC, SMPI, I-4 engine. The design reduces resonance within the engine's structure by increasing the engine block's natural frequency. A structural collar bolted to both the cylinder block and transmission case reduces vibration and increases stiffness of the en-gine/transmission assembly. The result: Chrysler's Cirrus, Sebring Convertible, and Stratus have quieter ride and smoother operation.
- LOW-RUMBLE INTAKE MANIFOLD. The redesigned intake manifold for Chrysler's 2.4-l, DOHC, SMPI, I-4 engine employs four tuned intake runners surrounding the plenum chamber as a cluster surrounds a focal point. The earlier design had the runners equally spaced lengthwise along the plenum. Air waves, out of phase at low speeds, caused a distinct rumbling sound. The new design keeps the air-pressure waves in phase, eliminating low-speed rumble.
- AIR INDUCTION RESONATOR. Chrysler's 2.4-l, DOHC, SMPI, I-4 engine has a new air induction resonator that is 103 cubic inches larger. The resonator connects to the intake duct that runs between the air cleaner and throttle body. The resonator works in conjunction with a redesigned intake manifold to enhance noise attenuation and dampen induction noise during low-speed wide-open throttle operation.
- SPORT-TUNED EXHAUST SYSTEM. A sport-tuned exhaust, introduced in '96 on the Indy 500 package, adds 15 hp and 5 lb-ft of torque to the 5.9-l engine that powers the '97 Dodge Ram Pickup. Revised tuning, available on the sport package, provides a throatier sound and reduces back pressure.
- MILESTONE ENGINE. At long last, Corvette this year rolls out the successor to its famed small- block V-8 engine, first introduced in 1955. Chevrolet engineers designed it from the ground up, combining the best of traditional and new engine technologies. They chose push rods over an overhead cam design, and configured the new 5.7-l all-aluminum engine to reduce the effects of combustion heat and energy, which can bend and distort an engine block. Result: The new design is stiffer, stronger, and has lower mass. It also offers improved fuel economy, less emissions, improved driveability, and greater dependability. Power is also increased: 340 hp at 5,600 rpm and 350 lb-ft of torque at 4,400 rpm.
- BOXSTER'S MID ENGINE. Powering Porsche's new mid-engine Boxster will be a 2.5-l, water-cooled, six-cylinder engine. Positioned in front of the rear axle, it produces 204 (DIN) horsepower and propels the car from 0 to 100 km/hr (62 mph) in 6.9 seconds. The car's top track speed: 240 km/hr (149 mph). Conceived for maximum ease of maintenance and repair, the engine drives auxiliary units such as air conditioner and generator by a single self-adjusting drive belt. Cam shafts and intermediate shafts are controlled by chains that should last for the life of the car.
- MORE VW DIESELS. In addition to the mid-size Passat, Volkswagen has added the Jetta and Golf to its line of Turbocharged Direct-Injection (TDI) diesel-powered vehicles for U.S. sale. The TDI engine offers performance characteristics comparable to a gasoline engine, with the fuel efficiency diesels are known for. Additionally, the engine is nearly as quiet as its gasoline counterpart. Key technology features include:
- Electronic Diesel Control (EDC). Multiple sensors and some 25 mappings manage the direct-injection process. The system assesses accelerator position, engine speed, coolant and fuel temperature, intake air amount, and intake manifold pressure. It then instructs the distributor injection pump to deliver a defined quantity of fuel at a precise moment to the injection nozzles. In addition, the system monitors and controls exhaust-gas recirculation and charge pressure to ensure low emissions.
- Exhaust turbo charging and charge-air cooling. These features further enhance compression ignition efficiency. The turbo charger compresses the combustion air, which is cooled in the charge air cooler and then directed via a specially shaped inlet swirl port into the combustion chamber. Swirl port shape, in conjunction with the combustion chamber which is let into the piston crown, results in the ideal compromise between torque, power, fuel consumption, exhaust emission, noise, and cold-start characteristics.
- JAGUAR'S FIRST V-8. With the introduction of Jaguar's new XK8 luxury sports car, comes a new engine: the 4.0-l, all-aluminum AJ-V-8. Compact and rigid, the 32-valve, 90-degree, quad cam claims a number of best-in-class performance features, including highest specific power (72.5 bhp/liter); highest specific peak torque (59 lb-ft/liter @ 1,500 rpm); lightest weight (441 lbs); highest engine power/volume (32 bhp/cu ft). Design features include an advanced combustion system, innovative air inlet manifold with integrally molded fuel rails, and programmable variable cam phasing. Result: more than 80% of peak torque is available between 1,400 and 6,400 rpm.
- PROGRAMMABLE VARIABLE CAM PHASING. Engine torque is directly proportional to volumetric efficiency which, in turn, depends on the time at which the inlet valves close. Jaguar's VCP increases torque at low speed by advancing the inlet camshafts to close the inlet valves early. At high speed, VCP achieves maximum power by retarding the inlet camshafts. Chief components comprise an hydraulic actuator mounted on the end of each inlet camshaft, and a pair of electronically switched oil-pressure control valves. Solenoids, activated by the engine-control module, switch the valves. The actuators contain a piston machined with helical splines. The piston acts on a matching set of splines in the actuator housing. When oil pressure is applied to the piston, it advances the inlet cam timing by 30 crank degrees, altering camshaft-to-crankshaft phasing. Removing oil pressure retards the camshaft via a return spring and natural friction. Response between advanced and retarded modes is under 0.7 seconds.
- BOXER GETS MORE PUNCH. Introduced just last year, Suburu's 2.5-l horizontally opposed (boxer) DOHC four-cylinder engine receives extensive changes for '97 that boost power 10 hp to 165 hp at 5,600 rpm. Engineers replaced the hydraulic valve lifters with solid ones, yet advanced alloy shims eliminate the need for adjustments until 100,000 miles. Other modifications include a redesigned combustion chamber with 9.7:1 compression ratio (0.2 higher than last year), increased piston pin to deck height, and tighter piston-to-cylinder clearance. The pistons have no valve relief cut into their tops and weigh 70 gms less each. A plenum and smoothed intake system broaden the torque band. The new engine peaks at 162 lb-ft at 4,000 rpm--up 7 lb-ft--yet at 2,800 rpm still produces more torque than last year's maximum. Amazingly, it also gets better mileage and now runs on regular unleaded fuel.
- FIRST ALPHA, THEN BETA. Hyundai's second in-house-designed engine, the Beta, appears in several 1997 models including the Elantra and all-new Tiburon. It's available in both 1.8-l (1,795 cc) and 2.0-l (1,975 cc) versions, producing 130 hp at 6,000 rpm and 140 hp at 6,000 rpm respectively. The 16-valve DOHC engines feature electronic fuel injection, hydraulic tappets, dual-aperture fuel injectors, and distributorless ignition. A modified pentroof combustion chamber with tumble port design helps reduce emissions, while the knock control system allows for a 10.0:1 compression ratio (10.3:1 in the 2.0-l engine). The addition of a cast-aluminum support web helps resist torsional flexing along the crankshaft axis. Engineers cut weight through the application of high-temperature plastics in the engine head cover, air cleaner housing, and water-pump impeller.
- SAME LOOK, BETTER TORQUE. The LS models of Mitsubishi's all-new Mirage receive an extensively updated 1.8-l engine that produces identical power and torque to last year's model (113 hp at 5,500 rpm and 116 lb-ft at 4,500 rpm), but over a broader rpm range. Based on the same block, the secret lies in a cylinder-head redesign, straightened intake manifold runners that reduce air-flow resistance, and better flowing stainless-steel exhaust header in place of the formerly cast-iron one.
- PRELUDE TO A PRELUDE. Honda fans eagerly await the fifth-generation Honda Prelude, due out in November. Expect a 2.2-l DOHC four-cylinder engine that leverages Honda's patented VTEC (Variable Valve Timing and Lift Electronic Control) technology to pump out 195 hp (190 hp with automatic transmission). The automatic features an optional sequential sport shift system--similar in concept to Porsche's Tiptronic or Chrysler's Autostick--that allows the driver, if desired, to manually select and hold gears, much like a manual transmission.
- SMALLER V-8. Infiniti's all-new Q45 might have been called the Q41. For 1997, the luxury sedan receives a 4.1-l DOHC, 32-valve V-8 instead of the previous model's 4.5 l. Lighter and more fuel-efficient, the engine makes 266 hp at 5,600 rpm and 278 lb-ft of torque at 4,000 rpm, 12 hp and 26 lb-ft less than its predecessor. A 10.5:1 compression ratio requires premium unleaded fuel despite the efforts of the engine's sophisticated Electronic Concentrated Control System (ECCS). The company says that straight-line acceleration should remain the same, thanks to a 204-lb reduction in the car's weight.
- ACURA V-6, MADE IN AMERICA. For 1997, the new 3.0CL coupe is propelled by a transversely-mounted, SOHC, all-aluminum 3.0-l V6 designed jointly in Japan and America and built at the Anna Engine Plant in Ohio. Engineered for broad power and torque delivery as well as excellent fuel economy, the VTEC engine produces an estimated 190 hp and is designed to run for 100,000 miles before its first scheduled tune-up.
- BIGGER V-6. Mitsubishi's Montero and all-new Diamante share a 3.5-l SOHC 24-valve V-6 design--up from last year's 3.0-l--tuned uniquely to meet the demands of each vehicle. In the Diamante, the engine produces 210 hp at 5,000 rpm and 231 lb-ft of torque at 4,000. Montero's version, by contrast, generates more torque at slower engine speeds, developing 228 lb-ft at 3,500 rpm and the same 200 hp at 5,000 rpm. Engineers applied CAE to determine the optimum thickness of the cast-iron cylinder block and placement of stiffening ribs. Four-bolt main bearings constrain the forged steel crank, while an aluminum head with roller-type rockers and hydraulic valve adjusters top off the block.
- BLOCK-FORGED RODS. The 3.5-l engine in the Acura RL is the company's largest ever. It is also the world's first to use a new block-forging process to manufacture extremely well balanced piston connecting rods. In block forging, a steel blank is struck at extremely high pressure from five directions at once. The process leaves no allowance for excess metal, thus the rod blanks are machined before the forging process to an exact and known mass. This eliminates the usual process of sorting and matching the rods by weight after forging to achieve a balanced engine. In fact, the company says that the RL's block-forged rods are the most precisely balanced of any production automobile engine.
GAINS IN DRIVE TRAINS
- ALL-WHEEL-DRIVE SYSTEM. The all-wheel-drive system that was unavailable on the Chrysler Town & Country and Dodge Caravan re-enter production in 1997. The system is functionally unchanged from prior years, except it includes a lighter viscous coupling. Major change to all-wheel-drive vehicles for 1997 is the use of rear-wheel disc brakes. The addition of rear disc brakes insures smooth, quiet operation with excellent high-speed fade characteristics. Single-piston sliding calipers operate on 11.4 x 0.5-inch solid discs. A drum-type parking brake is mounted inside the "hat" section of each disc similar to that used on other 4-wheel disc brake vehicles.
- LEADING-EDGE TRANSMISSION. Ford engineers collaborated on upgrading the 4R55E transmission to the 5R55E five-speed automatic transmission. The centerpiece of its design is patent-pending "swap-shift" technology. Upgraded components, new override drum and output shaft speed sensors, and sophisticated electronic controls enable an additional gear between what are first and second gears in the 4R55E. The transmission provides improved gear ratios that improve acceleration, hill climbing, and driving off-road. The 5R55E's new ratios are: first gear, 2.47:1; second gear, 1.86:1; third gear, 1.47:1; fourth gear, 1:1; fifth gear, 0.75:1.
- IMPROVED BUSHINGS AND SEALS. For 1997, Ford Thunderbird's standard 4R70W four-speed electronically controlled automatic overdrive transmission is upgraded in several ways. An improved bushing and triple-lip oil seal in the rear of the transmission, bonded-rubber seal accumulator pistons, and an improved thrust washer with a burnished turbine hub in the torque converter improve power transmission performance.
- AUTOSTICK. Originally available on the '96 Jeep Eagle Vision, Chrysler's electronic, driver-controlled four-speed shiftable AutoStick(R) Transmission Control System is now offered on the 1997 Sebring Convertible. AutoStick enables drivers to override the transmission's computerized logic when they want high-end performance. The system allows drivers to shift from automatic to manual and back again. Unlike conventional automatics, AutoStick in manual mode keeps the transmission in the gear the driver selects unless it senses potential engine damage.
- NEW TRANSFER CASE. Explorer 4x4 models feature a Control Trac system. The computer-operated transfer case is a Ford exclusive in North America. Revised to provide more on-road traction and off-road driving flexibility, the system has new power governing strategy and calibration. In "Auto" mode, the interactive all-wheel-drive system continually monitors and adjusts torque to the front wheels, minimizing NVH at maximum highway speeds. Under normal driving conditions, a transfer gear box at the transmission delivers a 65/35 rear-to-front torque split through a differential. A viscous coupling in the transfer case increases torque to either the front or rear axle, depending on where it is needed. In the 4x4 "high" mode, it electronically locks up the clutch in high gear, providing a 50/50 torque split between the front and rear wheels. If slippage occurs, the system transfers torque to the wheels that need it.
- AGGRESSION. General Motors' new 4T65E transmission, an upgrade of the popular 4T60E, features a gearbox designed to withstand the increased torque and power capacity for GM's supercharged 3800 engines. More noticeably, it also allows drivers to select "normal" or "performance" shift modes by pressing a button on the vehicle's center console. Performance mode provides higher shift points and more aggressive downshift calibration to approximate the crispness of a well-timed manual shift. The normal mode provides traditional low-end torque, but in a less aggressive sequence. Available on selected General Motors vehicles.
- LOW COMPONENT TRANSMISSION. The electronic, five-speed automatic transmission that debuted on the 1996 V-8- and V-12-powered models will be in all 1997-model Mercedes-Benz cars. Not only does the transmission feature five forward gears for better fuel economy and acceleration, it provides an additional "higher" reverse gear ratio, second-gear forward start, and lower overall shift points for maximum stability and traction on snow and ice. Instead of the traditional four gearsets and seven shift elements, the new transmission incorporates only three planetary gear sets and six shift elements. It has no conventional brake bands, only multi-plate clutches for both driving and braking the planetary gears. As a result, the unit weighs 176 lbs (down from 230 lbs), is one-half foot shorter, and uses just 630 parts where most automatic transmissions have more than 1,000 individual components.
Electronically controlled, the transmission shifts according to individual driving situations and styles. The embedded microprocessor networks with both engine and chassis management systems, as well as the ABS and traction-control systems.
- JAGUAR'S FIVE-SPEED. Jaguar's first five-speed automatic transmission, the ZF 5HP24, complements the carmaker's new 4.0-l AJ-V-8 engine. Design centers on a hydro-dynamic, low-inertia torque converter that features an advanced, slip-controlled clutch. The clutch achieves a near-locked condition at low speed in high gears for better fuel economy. Smooth gearshifting is achieved through electro-hydraulic actuation. A 32-bit, intelligent, electronic transmission control module (TCM) modulates the hydraulic control valves and determines the gearshift points as a function of vehicle speed, engine load, selector position, and the driver-selected mode switch position. TCM also adjusts shift points for extremes of temperature, traction control, cruise control, and road gradient.
Additionally, Jaguar's new transmission controls shift energy management via a Controller Area Network message from the TCM to the engine control module requesting a reduction in engine torque during gear shifts.
- MORE POWER TO THE OUTER WHEEL. Model SH Honda Preludes come with a new active torque transfer system (ATTS) that, unlike a standard differential, applies increased power to the outer wheel during a turn. The yaw control system uses gears under electronic control to effectively increase the drive ratio of the outer wheel. The end effect is similar to changing the outer wheel's diameter, and, as automotive engineers know, such a setup will cause the car to automatically turn towards the smaller wheel.
- FUZZY LOGIC OUT, NEURAL NET IN. Over the past several years, automotive engineers around the world have embraced fuzzy logic to govern the shift patterns of automatic transmissions. Now, Mitsubishi dispenses with fuzzy logic and applies a neural network in its adaptive transmission control management (ATCM) system. As with most neural nets, ATCM learns the driver's habits and adjusts the shifting strategy accordingly. It works by processing inputs from engine power, throttle, braking, and steering and then calculating the appropriate shift points on the fly. The resulting values can lie anywhere along a limited continuum, in contrast to systems that select a shift strategy from a preconfigured list of "maps." The result is a transmission that downshifts quickly and holds gears longer for aggressive drivers or shifts quietly at low speeds for gentle drivers. Should the driver's mood change, she/he is not locked in--the system resets itself each time the car is restarted.
- FLEXIBLE FLYWHEEL. Engineers designed a flywheel for Mitsubishi's new Mirage in which the flywheel mass and the crankshaft are dynamically separated by a flexible plate. The arrangement moves the resonant bending frequency out of the 200-500 Hz range, which is said to be particularly irritating to human hearing.
- HIGH-INTENSITY DISCHARGE (HID) HEADLAMPS. In the 1997 Lincoln Mark VIII, a clear lens covers what is believed to be the industry's largest passenger-car lighting housing in the world. Behind this transparent piece sits the integrated front lighting unit that includes the HID low beams, halogen high beams, and cornering lamps. The HID bulb, previously available only on the Mark VIII LSC, delivers 2.7 times more light than a typical halogen unit. The single-piece wrap-around front headlamp housings employ complex reflectors and fixed lenses to focus the light efficiently. HID lights draw almost 24% less energy than a halogen source on a per-bulb basis.
- REAR APPLIQUE NEON LIGHTING. The Mark VIII's restyled rear employs a one-piece, 48-inch neon tube with integral electrodes concealed under the applique. The neon tube runs full length across the top of a trunk-mounted central light bar. A dual-function electronic ballast can power the neon gas tube for both running- and brake-light functions. Although the neon gas tube is hidden from view, it projects light by bouncing it off a concave reflector. This construction gives the applique a three-dimensional effect that makes the car instantly recognizable. When the brakes are applied, a solid field of red appears through a clear acrylic lens that runs the full width of the trunk. The neon gas light reacts 198 milliseconds faster than an incandescent bulb. This means following drivers can react quicker, reducing their stopping distance by an average of 17.5 ft, at 60 mph.
- SUPPLEMENTARY TURN SIGNALS/PUDDLE LAMPS.The Mark VIII's mirrors contain a lighting module with supplementary turn signals and ground illumination or "puddle lamps," along its lower edge. The extra set of turn signals sits behind a clear lens on the lower edge of the mirror housing. Directional vanes separate the individual lighting elements, preventing the small, red, light-emitting diode (LED) lights from distracting either the driver or front passenger. The supplementary signals, however, are readily seen by drivers traveling in adjacent lanes. This improves safety by increasing the likelihood of other drivers seeing the turn signal. Just forward of the mirror-mounted turn signals are small lamps that activate when the door is unlocked via the remote keyless entry system. As the name suggests these "puddle lamps" light the area at the base of the door and add to safety by illuminating the parking surface. Puddles, potholes, and uneven surfaces near the door are easily seen.
- DYNAMIC SIDE-IMPACT PROTECTION. The U.S. government's new dynamic side-impact standard, which goes into effect in the 1997 model year, is expected to reduce side-impact deaths by about 10%. That's why more cars and trucks now employ steel door beams and cross-car reinforcement. Such vehicles as the Cadillac DeVille have taken a further step, making side airbags standard. Side airbags typically use the same pyrotechnic gas generator technology as front bags, but they react and inflate more quickly. Tests on DeVille's side bags revealed that they can cut thoracic trauma by 15%.
The Neon Coupe and Sedan both meet the dynamic side-impact-protection federal motor vehicle safety standard (FMVSS) for 1997. This standard requires a sturdier structure to resist intrusion during side impacts than the static standard. Neon doors and body structure were designed in anticipation of this requirement. Reinforcing side-guard-door beams resist intrusion during impacts and additional internal structure increases the vehicles' overall strength.
- SIX AIRBAGS AND SPACE FRAME. Coupling weight reduction with structural rigidity, Audi's 1997 front-drive A8 3.7-l and all-wheel-drive A8 4.2-l Quattro feature an all-aluminum space frame (ASF). Comprised of extruded aluminum sections, vacuum die cast components, and aluminum sheet, the ASF weighs 40% less than competitive steel units. Even so, rigidity is substantially greater than conventional unibody structures, with all ASF elements contributing to its load-bearing integrity.
Overall design functions as a safety cell; long members in the front and rear crumple in accordion-like fashion under collision loads. These use a hollow form structure and incorporate a cellular crushspace within the confines of the door. The beams, which interlock with the lower door sill, overlap the front and rear door pillars to spread impact load.
In addition to this structural protection, the A8 is said to be the first vehicle sold in North America to offer six airbags: two for the driver and front passenger in the event of a frontal impact; two for the driver and front passenger for side-impact protection; and two more side-impact airbags for the rear outboard seat occupants.
And, unlike door-mounted side airbags, the A8s are located in the seats. In this way, the airbags remain in optimum position no matter how passengers adjust their seats.
- CHILD-SEAT RECOGNITION. Mercedes-Benz has announced that its 2-seat SLK sports car, available in the U.S. in early '97, will come equipped with a child-seat recognition system. The Mercedes-patented system (supplied by Siemens) requires a special infant seat with built-in "resonator," similar to the security tags sometimes attached to merchandise in retail clothing stores. A low-power electronic signal from the car prompts a return signal from the resonator, allowing the system to sense the presence of the infant seat and automatically turn off the passenger-side airbag. The seat itself needs no battery or power hookup. In the event of a collision, the child is protected by the restraining abilities of the child seat and seatbelt system, as well as the side airbag.
- ACTIVE HEAD RESTRAINT. Introduced as standard equipment in the next-generation Saab models, an active head-restraint system limits head and neck whiplash. In a collision from the rear, the occupant is pressed into the backrest. Movement of a pressure plate in the seatback forces the head restraint upwards and forwards to meet the head before whiplash begins.
The force with which the occupant presses against the backrest, the magnitude of collision force, and occupant weight determine the amount of activation, tailoring system to individual.
- KNEE BAG REDUCES INJURIES. Kia's Sportage debuts with the world's first knee airbag. Located below the steering column, the bag deploys along with the standard chest airbag to help reduce forward movement of the driver's lower body under the dashboard. The company says that by redistributing the forces against the driver's body and by helping to maintain a more upright position, the knee airbag increases the effectiveness of the primary restraint systems. When fully inflated, it extends about 4.7 inches (120 mm) and also serves to reduce injuries to the knees and legs--areas that are prone to significant injury during an accident.
- BETTER BODY BUMPERS. By reducing the number of parts in the front bumper of the all-new Toyota Camry from 20 to 13, engineers created a design that is not only less expensive and lighter, but also provides five-mile-per-hour protection instead of two-and-one-half. They selected super-olefin for the bumper cover, an easy-to-form polymer that resists scratches and offers the surface smoothness of steel. In all, the front and rear bumpers weigh 40% less than last year's.
- STEERING IMPROVED. Improved steering control and responsiveness highlight 1997 enhancements for Ford's Crown Victoria. A new on-center detent stabilizes the control valve for straight down-the-road driving and improved steering precision. New bearings reduce friction and enhance steering gear precision. Reconfiguring the control valve and adding a smaller bearing also increase stability. A four-bolt sector cover, replacing the previous two-bolt design, enhances stability, security, and leak resistance of the large output shaft. Lightweight materials in the gear and valve housing reduce weight, while a new sector shaft and grinding process for finishing sector teeth improve the wear characteristics and help maintain the correct mesh load for constant on-center feel. Machining improvements create a smoother-acting gear and a tighter, more consistent recirculating ball fit between the worm and piston.
- GAS-CHARGED HYDRAULIC SHOCKS. The independent MacPherson strut front/Quadralink rear suspension on the '97 Mercury Tracer includes new gas-charged hydraulic shocks and revised spring rates for improved ride and handling. A redesigned, stiffer front-stabilizer bar improves handling during cornering. Modifications to front knuckles, the stiffer body, and a new solid stabilizer bar in the rear improve handling characteristics. An increase in wheel widths (from 5.0 to 5.5 inches), and new 185/65R14 low-rolling resistance tires are standard and also improve handling.
- BIGGER BRAKES. Mercury engineers increased the '97 Mercury Tracer's rear brake drums from eight to nine inches in diameter. Stiffer front calipers reduce noise. An integrated master cylinder/booster, designed with minimum lash in the piston stroke, works synergistically with an increased boost ratio, to provide increased power assist, and better pedal feel.
- AIR-RIDE SUSPENSION. The '97 Expedition offers an optional Ford-designed air-ride suspension system with four-corner load leveling on 434s and a rear load leveling system on 432s. The air- ride suspension uses computer-controlled compressed-air-filled front shocks and rear air springs to maintain a constant ride height under all road conditions. It provides extra stability, particularly for trailer towing, and maximizes riding comfort and control under all conditions. The system automatically lowers the vehicle for easier entry/exit after the ignition key is turned off. The system automatically raises, when in 434 low, to provide extra ground clearance for off-roading. When the vehicle is heavily loaded, the electronic control module senses the extra weight and diverts high-pressure air to the front air shocks and rear air springs to raise the vehicle and maintain a predetermined ride height. It will maintain the same ride height regardless of the load. Height sensors in the front and rear of the vehicle sense its position relative to the ground and signal the computer. The computer commands solenoids in the air distribution network to control compressed airflow. An on-board compressor generates compressed air for the system.
- SIDE- AND REAR-DOOR CHECK ARM SYSTEM. Check arms for hinged side and rear doors on Dodge's Ram Van & Wagon provide quiet, long-lasting operation. Two spring-loaded steel balls, traveling in nylon-coated tracks, control door motion. Balls roll into depressions in the track, at the 90-degree position, to hold the door open. The door can't open wider because a pin strikes a bumper mounted inside the door. This pin, easily removed by the operator, enables the door to open as much as 170 degrees for loading large items or to move closer to a loading dock. Hinge stops prevent contact between the door, door handle, and body sheet metal. A travel detent prevents the door from slamming shut after it is opened.
- CONTINUOUS STRUCTURE. To build the lightest but stiffest minivan possible, GM engineers employed a technique called the continuous structure. Major pillars and door frames run continuously down and underneath the floor to align with outriggers and cross members that tie into longitudinal rails. Efficient alignment and joining result in joints that are less susceptible to bending, torsional, and shaking forces. The net result is a structure free of creaks and groans over rough roads and one that also protects interior space in the event of a collision.
- STAY THE COURSE. Stabilitrak, a revolutionary development in driver control, determines what drivers want to do, then helps them stay on course. To accomplish that, it examines the output of a steering sensor and compares it to a yaw rate sensor and lateral accelerometer. If the system determines that the car is yawing undesirably, it applies one of the front brakes to bring the car back to the driver's desired path. As a result, it "recognizes" if a vehicle is skidding on ice, snow, or gravel, and corrects for it. It also helps bring a car under control if it enters an off-ramp too quickly. Standard on the 1997 Seville Touring Sedan, Eldorado Touring Coupe, and DeVille Concours.
- ALUMINUM SPACE FRAME. The all-aluminum space frame chassis of Audi's 1997 A8 3.7- and 4.2-l cars contributes to low curb weights: 3,682 lbs and 3,902 lbs, respectively. This compares favorably to the A8's competitors, including the Mercedes Benz S-Class (S320 @ 4,480 lbs, S420 @ 4,650 lbs) and BMW 7-Series (740i @ 4,145 lbs, 749iL @ 4,288 lbs, 750iL @ 4,553 lbs).
Low curb weight translates to high power-to-weight ratios. For example, the A8 3.7 propels only 16 lbs with each available hp, compared to the Mercedes-Benz S320 and S420, which have ratios of 19.6 and 16.9. The A8 4.2 is even better at 13 lbs per hp. Nearest rival: BMW 740iL with 14.6 lb/hp.
- COMPOSITE LEAF SPRINGS. Designers at Swedish car maker Volvo turned to composite materials to reduce size and weight of the rear suspension of its 960 model without having to sacrifice the Volvo reputation for ride comfort. A transverse leaf spring made of glass-fiber-reinforced epoxy replaces the steel coil springs that surrounded the shock absorbers in earlier models. The composite material was chosen for its stiffness; the leaf spring weighs just 2.5 kg and replaces two coil springs, each of similar weight.
- TORQUE-SENSITIVE STEERING. First came speed-sensitive steering, now Acura's RL and CL present a design based on steering-effort. The system varies power assist by monitoring the amount of torque generated between the tire and pavement as the steering wheel is turned. Should effort increase--no matter what the vehicle speed--boost increases to match. The system uses a steering rack with a rotary valve and torsion bar. The torsion bar twists in proportion to steering effort, and as it twists, it progressively opens a hydraulic valve to adjust boost. The company says the design greatly reduces power-steering noise, backlash, and kickback.
MATTERS OF STYLE
- GOOD VIBRATIONS. The seats in the Acura 3.5RL resulted from extensive research into the nature of bumps and vibrations and development of a means to minimize them. Using human factors studies, engineers discovered that the body has its own resonant frequency. Vibrations at this frequency can be very unpleasant, and human test subjects generally gauge the vibration felt in a car based on vibrations in the resonant range--usually between 5 and 10 Hz. To damp these frequencies, designers analyzed six different spring configurations for the RL's seats with NASTRAN, until they found one which met their expectations. The result: seats that decrease by 50% the upward force felt by test subjects.
- SHIFT BOOT DESIGN. Ford's five-speed G5M manual transmission has a new shift boot design. It employs a new shift lever, with better feel and more driver feedback. Additional synchronizers provide smoother reverse-gear shifts. The clutch pedal is easier to depress, and upgraded clutch materials match the SPI 2000 engine's improved performance. The 4EAT automatic transmission has a new torque converter and torque management during shifts for better powertrain matching, improved performance, and smoother shifts. Calibration changes in the EEC-V module help provide excellent fuel economy and smoothness in shift timing. The shift lever is shorter and more ergonomic.
- RIGHT-SIZED SUV. Joining its larger and more luxurious sibling, the Montero, is Mitsubishi's Montero Sport. Built on a 107.3-inch wheelbase, it will compete head on with Nissan's Pathfinder and Toyota's 4Runner. It is not simply a small Montero, but a completely new vehicle. Expect both two- and four-wheel-drive versions, with top-of-the-line models receiving a 3.0-l 24-valve V-6 engine.