Automotive Industries June, 2000 Around-The-World Engineering. Author/s: Don Sherman Creating the Ford Escape and Mazda Tribute SUVs was a global accomplishment. The chief engineers tell how it happened. Yoshihito Nagamoto must have gained a profound understanding of that old saw "when the tail wags the dog" in his role as program manager for project U204/J14 -- the new Ford Escape and Mazda Tribute SUV siblings. Ford hopes to sell at least 200,000 Escapes in the U.S. a year, vs. Mazda's more modest target of 35,000 units per annum, yet the joint team of engineers who worked under Nagamoto was heavily skewed in Mazda's favor. This cross-cultural approach grew out of common needs -- both companies sought new small SUVs -- and the never-ending quest for efficiency. "In the beginning, separate engineering projects were underway to develop new and largely unrelated vehicles," notes the 49-year-old Nagamoto, who was previously the program manager for Mazda's Sentia (929) luxury sedan. Ford had based its efforts on the Contour platform, Mazda on the 626. Nagamoto explains that when the decision was made to combine the programs, Mazda's basic structure and packaging concepts were selected and his team was assigned lead engineering responsibilities. Keith Takasawa, Ford's chief program engineer for the Escape, recalls, "Mazda did most of the engineering on the program because Ford had no spare engineering capacity at the time. We found there were more differences than normal between the two companies. This was truly a joint program, vs. having one company be the lead company." Nagamoto says the merging of Ford's and Mazda's interests meant that two distinct sets of requirements had to be accommodated by a common design. "Ford wanted a traditional trucklike SUV, sized smaller than its existing models, while Mazda sought more sophisticated catlike characteristics for the Tribute," he notes. Blending was achieved by co-locating 20 to 30 Ford personnel, including Ford's Takasawa, in Hiroshima, Japan, to create a joint Mazda-Ford management and development team. Mazda is responsible for the overall engineering, including ride and handling calibrations and powertrain development. Ford, in turn, is responsible for supplying its 2.0L Zetec 4-cylinder engine, 3.0L Duratec V-6, and CD4E automatic transmission. According to Nagamoto, while the major development work occurred in Hiroshima under Mazda's aegis, most of the powertrain calibration work was conducted in the U.S. The U204/J14 program lasted 28 months from design freeze to Job 1, somewhat longer than usual for Mazda, Nagamoto reveals. But he doesn't blame the extra time required on the conflicts and compromises inevitable when two cooks stir the soup. "Changes during development to meet aggressive functional and financial targets are a normal part of any program," he says. "Unique to this project is the fact that, after spending nearly three years engineering the products in Japan, our team had to move to Claycomo (Kansas City), Mo., to prepare for launch from Ford's manufacturing plant. That transfer is what added a few months to the program."

 

Asked about the challenges involved in the joint program, Ford's Takasawa admits that: * Mazda's home office engineers knew very little about the U.S. sport-utility market and vehicles. * They knew nothing about the North American supply base. * Full-service suppliers were a new concept. * There were a lot of cultural differences, language differences and a 13-hour time difference. "We held a lot of video conferences late at night and early in the morning," he says. * The Ford and Mazda product development processes were very different, and not compatible with each other. Takasawa credits Mazda with being a leaner company, "so in some ways they are faster. There's a big difference in the supply base. The Japanese suppliers have a quicker turnaround than the U.S. suppliers." Contrary to early speculation that the Escape and Tribute are a spin-off of Mazda's 626 midsize sedan, Nagamoto and Takasawa insist that U204/J14 is a clean-sheet design. "After the programs came together, we took one more hard look at the joint platform stables," Takasawa says. "But the answer was that there were too many customer compromises with any of the existing platforms." Like the 626, the SUV twins use a transversely mounted engine and transaxle, strut-type four-wheel-independent suspension, and unibody construction. Specific features such as the front and rear chassis subframes are also consistent with the 626% general layout, though there are no hand-me-down panels or parts. Notes Nagamoto, "The unibody approach is obviously typical of passenger cars. But for these products, we wanted car-like attributes plus the ruggedness expected of any SUV. The ability to surpass truck durability tests is a fundamental platform requirement." Takasawa, a 27-year Ford veteran who prior to the Escape had shepherded the original Windstar minivan as well as redesigns of the Explorer SUV and Ranger pickup, says, "The move to do a unibody sport-utility took a few people back at first. But I think the necessity of it became clear pretty quickly. "The unibody is the biggest driver for the interior room," he adds. "It offers a lot of vertical efficiency. We've got an inch more interior height than the Explorer, and a lower step-in height. We added the underbody rails to meet the truck durability and increase rigidity. It also gives the opportunity to manage crash energy better." According to Ford, the Escape passes the same grueling Kingman, Ariz., proving grounds tests as does its burly F-350 Super Duty pickup. Setting the vehicle's size was a critical requirement. Toyota's RAV4 and the Honda CR-V were identified as primary bogeys, recalls Nagamoto, but the team members agreed that the RAV4 was too small. The larger CR-V looked just right from Mazda's perspective, but the team had to address all of the constituents' needs. At Ford a hierarchy exists: the Escape's role is to be the smallest entry-level model and an appropriate member of a comprehensive lineup of SUVs. But the Tribute is Mazda's one-and-only SUV for world markets, and it had to serve both entry-level and one class higher needs.

 

The solution was a 103.1-inch wheel-base (virtually identical to the CR-V's 103.2-inch dimension) with expanded wheel-track and overall-width dimensions to provide significantly more interior room than is offered by Honda's SUV. "From this starting point, we worked to achieve the smallest possible exterior dimensions in combination with maximum interior space," explains Nagamoto. In the jam-packed mid-size SUV segment, the Ford and Mazda products slip neatly between Jeep's Cherokee and Grand Cherokee in size. Tall-wide-short exterior proportions fulfill the need for interior spaciousness without infringing on the Explorer in Ford's "Outfitters" stepping-stone SUV scheme. "With the Escape we wanted to attract different customers, but we don't want to cannibalize Explorer sales," Takasawa says. "We wanted to go after all those people who are driving cars who have significant interest in SUVs, but face a number of barriers with our existing offerings, such as being big and clumsy, low fuel economy or the price was too high." To avoid cross-talk and confusion in the marketplace, exterior skins are unique to each product with shared surfaces limited to the windshield, roof and roof pillars. Inside, common components am the center console and minor trim items, Nagamoto says. Each maker chose somewhat different functional characteristics. Nagamoto calls the Escape more truck-like and traditional in scope, albeit notably more sporty in character than most of the SUVs on the market. To suit Mazda's credo of stylish, spirited products, the Tribute ventures an extra step further in the sporty-driving direction with larger base tires, firmer suspension calibrations, a quicker steering ratio, and a more aggressive shift schedule programmed into its automatic transmission. One of the more notable aspects of the project was tailoring Ford's Zetec and Duratec engines for their first truck applications. The high-winding, multivalve engines were re-tuned for grunt work with new reinforced-plastic intake manifolds designed to boost the lower half of their torque curves. An oil cooler is standard on the Zetec four while one is optional (in a trailer-towing package) on the Duratec V-6. Plastic cam covers save weight and cost. Front accessory drive systems and exhaust manifolds are also specific to this application. A new cast-aluminum oil sump for the V-6 improves both cooling performance and off-road damage resistance. A Mazda-designed combination windage tray and lower block reinforcement made the leap into all Ford Duratec engine applications. As a new twist on the venerable world-car concept, this Mazda-Ford joint venture appears to be a fruitful way to stretch resources and still satisfy each constituent's specific needs. If customers concur that the Ford Escape and Mazda Tribute really are desirable, high-value SUVs, this could be the ideal model for future product programs. RELATED ARTICLE: Fancy Footwork

 

An innovative coupling supplied by Toyota, and a Dana differential, make Escape/Tribute a capable off-reader, without turning into a monster truck. Mazda drew on its previous all-wheel-drive sedan experience to devise the innovative on-demand four-wheel drive system offered on the Mazda Tribute and Ford Escape. In fact, early in the development process Ford had been looking at a more conventional four-wheel-drive system, notes chief program engineer Keith Takasawa. But the Mazda engineers won the support of the Ford team. For four-wheel-drive versions of the Tribute and Escape, a power-take-off unit bolted to the transaxle spins a two-piece driveshaft connected to a device called a Rotary Blade Coupling (RBC), mounted to the nose of an otherwise conventional rear differential. As long as the front wheels don't slip, the rear half of the driveline is merely along for the ride. When there is a rotational velocity discrepancy (resulting from diminished front-wheel traction), interleaved blades inside the RBC begin churning a silicone fluid. The heat so generated rapidly raises the temperature and pressure of the air also sealed inside the chamber. This pressure rise forces a piston against a multi-plate clutch pack. When so engaged, the clutch pack completes the link between the spinning prop shaft and the rear differential, dispatching engine torque to the rear wheels. As soon as front and rear wheel speeds get back in synch the process reverses and the operating mode reverts to front drive. A second mode is also available. For off-road or "get-unstuck" use, the driver may press a "4x4 On" button on the dash of the Tribute, or turn a switch on the Escape. Each sends an electrical current to an electromagnetic coil adjacent to the RBC. This engages a small multi-plate pilot clutch in the RBC unit, which in turn applies the main clutch though a ball-ramp thrust-amplification device. The drive torque available in this mode is nearly seven times greater than the maximum torque available in the on-demand mode. Toyoda Koki (a Toyota subsidiary) supplies the RBC device and clutch packs to Dana which, in turn, adds its differential to the assembly. The beauty of this mechanical approach is that it's light, relatively compact, and smooth in operation. Since no wheel-speed sensors or electronic circuits are necessary, four-wheel drive can be offered as stand-alone optional equipment independent of (an expensive) ABS system. -- Don Sherman RELATED ARTICLE: "Escaping" The Truck Formula Chief engineer Keith Takesawa guided the creation of a comfortable, roomy SUV that survives Ford's truck tests. He dreamed of flying jet fighters, but for most of his 27-year tenure at Ford Motor Co., Keith Takasawa has been piloting trucks. His latest project--chief engineer of U204 (the Ford Escape subcompact sport-utility and its European cousin, the Ford Maverick)-puts the 49-year-old engineer at the center of a crucial joint-development project with Ford affiliate Mazda. The program required Takasawa to move to Hiroshima, Japan, for more than two years.

 

Prior to the Escape, Takasawa was a business director in the Large Car Vehicle Center, working on projects such as the reconstituted Thunderbird. He also headed up the 1995 revamp of the Ford Explorer and Ranger that included a new powertrain, and served as program manager for the first-generation Windstar minivan. He began his Ford career in 1973 on heavy-duty truck brakes. Q: What was Ford's major input in this project?. A: Mazda has no real knowledge of the U.S. truck market, so we brought our light-truck experience. That helped in numerous ways, including marketing concepts and equipment. There were 250 Ford engineering requirements that had to be met. Among the things driven by the Ford requirements were the ability for trailer towing, adequate engine cooling and safety-related design. The vehicle had to pass our truck durability tests. We expect the Escape to get a 5-star rating in the government crash tests. Q: How did you size up the competition as you started the Escape program? A: In the entry-level sport-utility segment, some of the competitors were too car-like, like the Honda CR-V. The Toyota RAV4 is a unique animal, it's substantially smaller. We wanted to be bigger than that, so we settled on a size like the CR-V. But the CR-V doesn't perform well in mud and sand. The RAV4 does better there. We also looked at the Jeep Cherokee, and then as they came out the Nissan Xterra and Suzuki Grand Vitara. We think we're breaking new ground with the Escape. The front compartment has almost as much room as a Grand Cherokee. It also has a wider track by two inches, although the body width is not much different. Q: Since Ford and Mazda were both doing their own programs before the U204 program started, why didn't you use one of the existing projects? A: After the programs came together, we took one more hard look at the joint platform stables. But the answer was that there were too many customer compromises with any of the existing platforms. With the Contour, if you kept the chassis and floor-pan, then the people package was very inferior. To meet the durability requirements, you would have to rework the underbody structure and make changes to accept an independent rear suspension. And there were rear seat issues with the Contour. Mazda had similar problem areas, particularly in durability. The 626 platform had a bigger package area. We could have patched the platform to make it work, but then you would need to rework the structure for the rear suspension. Q: What was your reaction when told that the Escape would be Ford's first production hybrid-electric vehicle? A: My first reaction was not one of terror. I thought this is really neat, this is the best vehicle to do a hybrid on. We need to be developing cleaner vehicles, and mainstream vehicles with the flexibility and capability of an SUV is dead on. To make the biggest impact you need to make HEVs out of mainstream vehicles.

 

-- Dale Jewett