2002 Import Tech Report

Transcription

1 2002 Import Tech Report BY PAUL WEISSLER A bevy of new models and high-tech engines, plus a revolutionary new CVT, highlight this year s offerings from the import carmakers. European and Japanese carmakers sell primarily cars and car-type SUVs, particularly in the U.S., so it s no surprise those vehicles usually get the bulk of the investment in new-model technology. Volkswagen, for example, has a technology leader in its new Audi A4, which has a new 3.0-liter V6 26 December 2001

2 Jaguar X-Type Acura RSX Coupe Toyota Camry December

3 2002 IMPORT TECH REPORT and the world s first continuously variable transmission (CVT) that can be mated to a high-torque engine. That s just for openers. Next year, VW will be introducing the first-ever W8 engine (a marriage of two 15 /singlehead V4s) in the first luxury sedan to carry the VW nameplate. A year later, look for an ultra-luxury model with a W12 (two single-head V6s on one block) and even a W10 diesel. But Above: The Toyota Camry s new 2.4-liter Four develops a lot more power than the old 2.2, yet is designed for quieter operation. Notice the full-circle shape of the engine rear, to evenly distribute clamping loads to the transaxle, to reduce vibration. Below: One of the 2.4 s two gears for the counterrotating balance shafts is made of resin, as shown here. The plastic gear keeps tolerances tighter while also contributing to noise reduction. Photos: Paul Weissler that s going to be then; what s out now? For one thing, Honda has a brandnew four-cylinder for its new Acura RSX coupe, the Integra replacement, and a reworked Four in its car-type CR-V sport/ute. Nissan s new Altima, meanwhile, has a 2.5-liter Four to replace its 2.4 Four, and there s a lot more involved in this engine than just bumping up the displacement.1 liter (6 cubic inches). Then there s Toyota s best-seller, the Camry. It also has a new fourcylinder engine a 2.4- liter powerplant that replaces the 2.2. Why all these new engines (and redesigned versions from Jaguar, Subaru and Infiniti)? Aside from a little extra displacement, they use more efficient production processes, are lighter yet stronger and do everything better run quieter, produce lower emissions with more performance and carry longer maintenance intervals. Now let s run down the imports car line by car line and see what s new technologically speaking for Toyota/Lexus When you re as big as Toyota, you typically have a lot that s new. This year is no exception, with an all-new Camry and Lexus ES 300, and a stylish new sports car/hardtop convertible, the SC 430. The new Camry has grown almost an inch outside, to 189 inches overall, plus there s 5 more cubic feet in the interior and 2.6 cubic feet added to the luggage compartment. It s continued on page 37 If the chart at right is missing, please circle #31 on the Product Information Card on page December 2001

4 2002 IMPORT TECH REPORT Front The underbody of the Lexus SC 430 has six spats (red arrows) to direct airflow. They help reduce wind noise while improving handling and high-speed stability. as all-new as cars get, although the 3.0 V6 is basically a carry-over. The base engine, which replaces the long-in-the-tooth 2.2-liter Four, is a DOHC chain-driven 2.4-liter Four that was introduced late last year in the Highlander SUV. It produces 157 hp at 5600 (21 more than the 2.2) and 162 ft-lb of torque (up 14 over the 2.2) at 4000 rpm. Its long stroke (96mm), combined with variable valve timing on the intake cam, helps produce good low-end torque. VVT also eliminates the EGR valve and helps top-end performance. The 2.4 has a pair of counterrotating balance shafts in the oil pan to minimize vibration, and one of them has a new resin gear to reduce noise. Ignition is coil-on-plug, and new iridium-tipped spark plugs carry a 120,000-mile service interval. Drive-by-wire continues its takeover from the throttle cable, and the 2.4 Four is its latest conquest. Toyota also has been phasing in a new 12-port fuel injector (largely for emissions control), which is on both the new 2.4 and the 3.0 V6. Although the 3.0 itself is basically unchanged and still rated at 192 hp, the 2002 version is not totally a carryover. It s now tuned to ULEV emissions standards and, in addition to the new injectors, there s drive-by-wire throttle, plus a coil-on-plug ignition system with the 120,000-mile iridium-tipped plugs. As for the Lexus ES 300, it used to be just a gussied-up Camry. But the 2002 model continues to differentiate itself in significant ways. It s somewhat larger, being built on the 107-inch Avalon wheelbase. Yes, it has the 3.0 V6 that s optional on Camry, but this one is the more powerful version also used in Avalon (210 hp vs. Camry s 192). The V6 is mated to a new five-speed automatic, vs. the Camry/Avalon four-speed. The ES 300 s standard braking system is a Camry option four-wheel discs with ABS and computer-aided brake assist for hard stops. In addition, the floating front calipers on the ES 300 are a two-piston design (both on the inboard side, where they make brake application more even, for better antisqueal properties). Automatic-dimming, heated outside mirrors are standard on the ES 300, and the list of luxury touches is a long one. The new SC 430 hardtop convertible is a lot more than just an SC 400 with the 4.3-liter V8 from the LS 430 stuffed in. It has an underbody shaped to smooth airflow, which does doubleduty reducing wind noise while improving straight-line stability. There are six spats that help direct the airflow one forward of each front and rear wheel and one at each rear side The SC 430 s decklid opens at the front to stow the hardtop, then at the rear to help load the rather small luggage compartment. December

5 2002 IMPORT TECH REPORT A B C Measuring Portion Measuring Portion Measuring Portion Lexus now has specs to check the 4.3 V8 s plastic region bolts for possible reuse. Illustration A shows a head bolt, which should be at least.382 inch (9.70mm) thick. Illustration B shows a connecting rod bolt, which should be at least.275 inch (7.0mm) thick. Illustration C shows a main bearing cap bolt, which should be at least.284 inch (7.2mm) thick. V-brace. A check for missing spats should become a part of any underbody inspection during an oil change. The retractable hardtop system has 10 motors and 13 switches, but a pair of mechanical features make possible the convenience of a fixed roof. The rear package shelf, for example, has both a motor to tilt it and a cable system that moves part of the trim, to position it for clearance while the top is in motion. The decklid is latched and pivots at the rear, while the front end goes up to allow the top to be stored. The decklid also unlatches and goes up at the rear (pivoting at the closed front end), for normal use of the rather small luggage compartment. Run-flat tires are an option on the SC 430, so if you have to service them, check the supplier s instructions (Goodyear or Bridgestone) for specific techniques. The 4.3 V8 has plastic region cylinder head, main bearing and connecting rod bolts, and if they haven t stretched much, they can be reused. Toyota now has a way to check their reusability, by measuring the shank diameters and comparing them to specs. Mercedes A Mercedes for only $25,000? Hey, the three-pointed star has to compete with BMW here in the U.S., and the truth is that Mercedes always marketed medium-priced cars in Europe. The C-Coupe is based on the C- Class (shortened 7 inches, to 171). However, instead of a V6, it has a 2.3- liter Four supercharged to 192 hp, exactly what s used in the more expensive SLK roadster. There are power windows and door locks, but Mercedes saves money with such innovations as a fully manual eight-way adjustable driver s seat. Subaru Subaru s image has always been solid, dependable and all-wheel-drive. Now it s looking to cultivate a performance image, with the 2002 Impreza WRX sedan and wagon. These vehicles feature stealth styling not exactly flashy, to say the least. But under the hood is a very potent 2.0-liter flat Four, with an intercooled turbo, that produces 227 hp at six grand and 217 ft-lb of torque at 4000 (both numbers substantially higher than the 165 hp/166 ft-lb of the larger displacement 2.5-liter Four). The long-used viscous coupling in the center differential continues on all Impreza and Outback Sport manual transmission models. However, A large cover hides the fact that the engine in the new all-wheel-drive Jaguar X-Type is transversely mounted. Two V6s are available. Photo: Paul Weissler 38 December 2001

6 the automatics get an electronically controlled multidisc clutch for frontto-rear torque transfer, with WRX models also getting a viscous coupling-type limited-slip rear axle. Jaguar Jaguar now has its first all-wheel-drive model, the X-Type, a near-luxury model with a $30,000 price tag. It s based on the new Ford Mondeo platform, the European name for a platform that previously served as the underpinning for the less-inspired (and now discontinued) Ford Contour. The X-Type uses both versions of the Ford Duratec V6 that has undergone enormous change since Jaguar adopted it for the S-Type three years ago. If you look under the hood, you can t even tell they re transversemounted, and the AWD is intended to help you forget. It s a viscous coupling system, and the power takeoff is on the passenger s side, a flipped version of the usual layout. The Jaguar versions of the Duratec have nothing left from the Ford engine but the physical architecture. The internals are all-new, including a precision cooling system developed by Jaguar. Both engines have 30 infinitely variable valve timing on the intake camshaft, using a Denso vanetype actuator (similar to what Denso also sells to Toyota/Lexus), and a twostage intake manifold. This combination is tuned for good low-end torque, because both V6s are not long-stroke. The base 2.5 V6 is basically square (81.6mm bore x 79.5mm stroke) and produces 192 hp at 6800 and 180 ft-lb of torque at 3000 rpm. The big-bore 3.0 is oversquare (89x79.5mm), developing 231 hp and 209 ft-lb of torque at the same rpm. The cooling system on both engines is based on the Jaguar 3.9-liter V8. The block has a low fluid capacity to speed warmup at low rpm. This means there s less coolant that has to be pushed through narrow passages. So with the same pump capacity (close to the 4 liters per second of the Jag V8), flow velocities are greater, Photo: Paul Weissler The all-wheel-drive system on the Jaguar X-Type is flipped to the passenger s side, which increases the driver s real estate. A viscous coupling is used to modulate torque transfer to the rear differential. and effective engine cooling is maintained. The pattern is a full-flow design all the coolant goes past each cylinder, which keeps metal temperatures down. The coolant used is a pure OAT (organic acid technology) formula, very similar to what GM and VW/Audi have been using, and the dye color also is orange/pink. It s different, therefore, from the corporate hybrid coolant Ford will be introducing on its domestic cars and light trucks, which will have a yellow dye. The two coolants should not be mixed. Audi The new Audi A4 features one of the most innovative engineering developments of the year a Multitronic CVT mated to a choice of two highperformance powerplants, a 1.8-liter intercooled turbo and a new 3.0-liter V6. It s the standard automatic on front-drives, The Multitronic continuously variable transmission in the Audi A4 is the first CVT that can handle high torque. Yet it weighs over 20 pounds less than a conventional automatic. For openers, it ll be available only on front-drive models. December

7 2002 IMPORT TECH REPORT Pulling Away Engine Starting Clutch Variator Link-Plate Chain Oil pump Hydraulic Control Electronic Control Variator With Link-Plate Chain Overdrive This illustration shows how the Multitronic CVT works. Split pulleys, with one half pulley that can slide to or away from the other, permit a change in pulley diameter in which the chain rides. For example, as the input shaft pulley halves come together, the chain is forced to maximum pulley diameter on the input shaft. This chain movement simultaneously pulls the output shaft pulleys apart, so the output pulley goes to a smaller diameter (and the chain moves to minimum diameter). That s equal to a large gear on the input shaft driving a small gear on the output shaft low gear in a conventional transmission. Reverse the arrangement and the transmission goes into overdrive. and will be available with Quattro AWD in a year or two. The terms CVT and high-performance have never been used together before, even with a steel link belt. That s because there s a limit to the torque that can be transmitted when one link is pushing on the next, to transfer power from one set of split pulleys to the other. Everyone else has been using the steel link belt (hundreds of links around which steel retaining bands are wrapped), from the Subaru Justy of the mid-1980s through the Honda Civic and new Saturn VUE. The Audi CVT uses a novel steel chain, and although it seems to work like a conventional CVT, there s a big difference: Each link is connected to the next by joint pins that are really mini-clutches clamped between the pulley halves by hydraulic pressure. So the chain functions as a puller, transferring power by pulling on the output pulley. The links are of two different lengths in sequence, which is enough to change the engagement sound pattern at the split pulleys, for quieter operation. The clamping pressure is determined by a mechanical torque sensor. It s basically a pair of steel shells with seven built-in ramps and steel ball bearings inside that produces a side force against a hydraulic cylinder piston proportional to input torque. The Multitronic CVT produces simulated gear-shifting. There s no actual shifting, so you don t feel anything, but you can hear the rpm hit a peak, then drop slightly, just as if it did. In addition, there s a Tiptronic feature six forward speeds that can be manually selected at the shift lever or by flipping switches on the steering wheel. The six speeds are just numbers in a computer program, of course, but the ratio changes actually do occur. The transmission is filled with Dexron, with a fluid change specified at 40,000-mile intervals. The new 3.0 V6 is an all-aluminum belt-driven DOHC engine, which replaces the cast-iron block 2.8 V6. It has Audi s familiar five valves per cylinder (three intake) and produces 220 hp at 6300 rpm and 221 ft-lb of torque at 3200 rpm. The engine has variable valve timing on both the intake and exhaust cams, a first for high-volume engines. The intake timing is infinitely variable in a 42 range; the exhaust has two positions 10 advanced and 12 retarded. Thermodynamic studies show that the combination of the two exhaust timing numbers with the infinitely variable intake is virtually identical in overall performance to infinitely variable timing on both camshafts. The 3.0 has a 90 bank angle, not the 60 that would provide inherent 40 December 2001

8 smoothness. So a single balance shaft is required, integrated with a chaindriven oil pump in the pan. The A4 has three CAN (Controller Area Network) data busses a highspeed one (500 kilobytes/second) for the powertrain and two medium-speed (100kB) types. One medium-speed CAN is for such comfort/convenience accessories as HVAC, power seats, windows and door locks; the other is for information, such as the sound system and telephone, navigation, etc. At this time, all the diagnostics are ISO (Keyword 2000 protocol), although a new adapter for the dealer technician tester was released for diagnostics beyond OBD II generic. Honda/Acura Honda has two important new models for 2002, the CR-V car-type sport/ute and the Acura RSX, which replaces the Integra. Both are highvolume models built on a small-car platform, which now features MacPherson struts up front. Honda, which long promoted its doublewishbone front suspension, switched to struts when it introduced the new Civic in Sure, struts increase the turning circle of a vehicle, compared with double-wishbones, but they also take up a lot less space, and engine compartment real estate is worth a great deal these days. Besides, the carmakers have learned a lot about tuning ride and handling with struts, such as specific durometer rubber bushings. This makes it tougher on aftermarket suppliers, of course. Honda s forte is the four-cylinder engine, and the company that invented variable valve lift and timing control has taken some important new steps in the designs of its engines for these vehicles. Their architecture is basically the same, but (in a continuing program) the engines have been turned 180, so the belt-driven accessory end is now on the passenger s side (and the crankshaft rotates clockwise). The objective is to put the exhaust system at the rear of the engine. This permits packaging a system with a shorter path to the catalytic converter so it heats up faster, for lower emissions. The Acura RSX is a two-door coupe, like the Integra, and it has a new 2.0-liter DOHC four-cylinder in two versions, both of which get infinitely variable intake valve timing. The standard engine produces 160 hp at 6500 rpm. The S (sport) engine develops 200 hp at 7400 rpm, which at 100 hp per liter matches the highest that Honda has done with a naturally aspirated setup. Interestingly, the standard engine has a dual-path intake manifold (shorter paths for high rpm), but the S engine has just a one-path (single fixed shape) intake manifold. The reason: The S engine accomplishes even more with its more sophisticated valve lift control system. The standard engine uses a two-rocker setup, where the second intake valve is barely open at low rpm (just enough to prevent fuel puddling in the intake manifold), enhancing combustion chamber swirl for good fuel mixing. The S four-cylinder has the NSX sports car s three-rocker setup for both the intake and exhaust valves, customizing valve lift and cam profiles of each camshaft at both low and high rpm. Both engines have a timing chain, and you can assume that DOHC and a chain is where Honda is heading with its small, high-revving engines. Honda apparently is learning to work with today s silent link chain designs. The accessory belt is a self-tensioning serpentine type, the ignition system coil-on-platinum plug and the valvetrain a precision-machined system (eliminating periodic valve clearance adjustment checks). These features allow both RSX models to carry a 110,000-mile tuneup interval. The bottom end of both engines is beefy a structural aluminum oil pan, forged crank and connecting rods and an aluminum crankshaft bedplate with cast-in iron alloy inserts at the bearing caps. The 2.0-liter DOHC S engine in the new Acura RSX has a three-rocker setup for variable lift on both the intake and exhaust camshafts, a design adapted from the NSX. The setup allows a single-path intake manifold to be used. December

9 2002 IMPORT TECH REPORT Nissan s new 2.5-liter four-cylinder for the Altima is all-aluminum, and very different from the 2.4 Four it replaces. As is evident here, a coil-on-plug ignition system has replaced a conventional distributor. Inlet Thermostat Cylinder Head Thermostat The 2002 CR-V has a reworked 2.4-liter Four (up from 2.0 liters), and still uses a timing belt setup. However, valve timing now is infinitely variable, a la the RSX. Bore is increased from 84 to 87mm and stroke from 89 to 99mm, making it an even longer-stroke engine, which contributes to better low-end torque (up from 133 ft-lb at 4500 to 162 at 3600 rpm). Horsepower also is up, from 146 to 160. At 2.4 liters, the stroker engine has to deal with second-order shake (two vibration pulses per crankshaft revolution). And as is the usual approach to reduce vibration, it The Nissan Altima s new 2.5-liter Four has a two-stage cooling system, using both an inlet thermostat and a cylinder head stat that can close off coolant flow through the block to speed warmup and reduce friction. Photos: Paul Weissler has a pair of counterrotating balance shafts in the oil pan that are driven off the rear of the oil pump. The CR-V continues to use Honda s Real-Time four-wheel-drive system, which is basically front-drive in good-traction situations. A propshaft from the front transfer coupling goes into a traction coupling with an oil pump and multiplate clutch, and a rear axle that drives a second oil pump. When the front tires slip, the traction coupling oil pump produces more pressure than the rear axle pump, and the pressure difference applies the clutch to transfer torque proportionally to the rear axle. The 4WD system and the automatic transmission both carry a 90,000-mile fluid drain interval. Nissan/Infiniti The big news at Nissan for 2002 is the all-new Altima. Yes, it has an optional high-output (240-hp) 3.5-liter V6 from the Maxima (in which it develops 255 hp), but most customers will choose the brand-new DOHC 2.5-liter Four, a leading-edge all-aluminum design with a two-stage cooling system that replaces last year s 2.4-liter four-banger. Eliminating the cast-iron block and dropping the distributor in favor of coil-on-plug ignition are obvious moves, but internal changes are important, too. Like its predecessor, the 2.5 is a long-stroke engine (100mm) for good low-end torque (180 ft-lb at 4000). It s a DOHC design with counterrotating dual balance shafts in the oil pan. What sells it is performance 175 hp at 6000 rpm, close to a lot of competitive V6s (and 25 more horses than last year s 2.4 Four). This is an engine of the future for Nissan, which also has a direct-injection version for the Japanese market. The cooling system on the 2.5 uses two thermostats. There s a normal 195 F inlet stat at the front and a second at the rear of the cylinder head. The one at the head divides the coolant flow. It allows flow through the head to cool the combustion chambers, but shuts off the path through the block so cylinder bore 42 December 2001

10 temperature increases, warming up the block faster to reduce friction. When the coolant temperature hits 203 F, the cylinder head stat opens fully to maintain that temperature for piston cooling. Obviously, both stats have to open at the right temperatures, something to remember when you get around to servicing this engine. The new 2.5 has infinitely variable valve timing on the intake camshaft, and there are different timing strategies for low, medium and high speeds, with the low/medium timing strategies doing the double-duty of maintaining torque while providing enough overlap to provide internal EGR. The camshafts are chain-driven, but the chain itself is a new design. Not only is it a fine-pitch, for quietness, but each link has a curved double-lobe shape, which reduces impact forces as it meshes with the sprocket teeth, for extra quiet and longer life. The new Q45 is powered by a 340- hp, 4.5-liter V8 (74 more horses than the 4.1 V8 it replaces). The cylinder heads actually are patterned after those in the 3.5-liter V6 used in the Infiniti I35/Maxima and new Altima, with one more combustion chamber per head. To reduce valvetrain weight, the 4.5 s valves are titanium. Front suspension is by MacPherson strut, along with a sway bar and strut tower bar. The Q45 is known for its good handling, and obviously Nissan believes a well-tuned Macstrut setup can provide it. The rear suspension is lighter than its predecessor, thanks to aluminum links and knuckles. The ultra-luxury class in which the Q45 participates calls for a lot of electronics, and this model has lots, including optional adaptive (laser) cruise control and high-intensity discharge (HID) headlamps. Visteon s voice recognition system is available to control the sound, HVAC and (partly) the navigation system. A novel electronic feature is a Silencing Lobes The new-design timing chain used on the Altima s 2.5-liter Four has a doublelobe shape on each link, to soften the engagement impact with the cam and crank sprocket teeth for quieter operation and longer service life. miniature camera mounted behind the license plate, which displays the area behind in the rear-view mirror when the transmission is shifted into Reverse. Like the SC 430, the Q45 has optional run-flat tires with a tire pressure monitoring system. Mitsubishi The Mitsubishi Mirage, an econocar and not a particularly hot seller, has finally been deep-sixed in favor of the Lancer, a much-redesigned Japanese-market sedan a bit smaller than the Galant. The Lancer has a SOHC 120-hp, 2.0-liter Four, compared with the Galant s DOHC 140-hp 2.4 Four. The Lancer is 178 inches long on a 102-inch wheelbase and has 94 cubic feet of cabin volume. Compare that to the Galant s 188 inches overall length on a 104-inch wheelbase and 98 cubic feet. The 2.0 Four has a cast-iron block, but the engine is anything but lowtech. The crankshaft is supported by a steel bedplate for the main bearing caps. The powertrain controller is a 32-bit microprocessor, so it s right up there in computing power, which helps it pulse-width-modulate the speed of the radiator s electric fan. The Japanese platform rails were beefed up for the U.S. market, and there are substantial front and rear crossmembers plus a dashboard crosscar beam, to stiffen things up. In addition, Lancer is loaded with extras for smoothness and quiet operation, from a pair of hydraulic engine mounts to a premuffler that helps silence high-frequency exhaust noise. There are also three intake resonators, a damper on each axle shaft (left side to reduce final drive noise, right side to suppress boom from its extra length), and urethane foam blocks in the floor and doors. The rear control arm bushings are dual-durometer types (soft fore-aft to absorb impact, stiff side-to-side to improve handling). Mitsubishi historically does a good job with powertrain layout for service access, and the Lancer is no exception. While everyone else is adding spacerobbing strut tower braces across the top of the compartment to improve handling, Mitsubishi achieves the same effect by reinforcing the strut towers, firewall and side sheet metal inboard of the wheel openings, then tying all the reinforced areas together. The Lancer comes loaded with a/c and power windows, door locks and outside mirrors as standard equipment. This car could be a high-volume seller, something its predecessor definitely wasn t. Visit to download a free copy of this article. Copies are also available by sending $3 for each copy to: Fulfillment Dept., MOTOR Magazine, 5600 Crooks Rd., Troy, MI December