Lambda, Lambda, Lambda

Just as the feeble nerds of the Lambda, Lambda, Lambda fraternity took on the jocks at Adams College in 1984, a recovering GM is about to venture into competition with some of the most respected brands in the industry in a segment that is expected to be the growth driver for many years to come. Representing the “nerds” is the aptly named Lambda platform, GM’s first-ever full-size crossover foundation that will support a product trifecta comprised of the Saturn Outlook, GMC Acadia and Buick Enclave. The newcomers are poised to take the “jocks”: Acura MDX, Audi Q7, Toyota Highlander, Volvo XC90 and Honda Pilot. These brutes have helped to propel the crossover segment from an annual base of 250,000 units to more than 500,000 units and growing. In 2000, GM began toying with the idea of a full-size crossover—some would say taking six years to develop a platform is a sign that the “old” GM lives on—and development took on several different forms. GM looked at developing a Nissan Murano-type crossover by stretching an existing passenger car platform to fit the dimensions needed to accommodate multiple occupants and their stuff. The experiment was deemed futile as mass grew out of control, pushing the dynamics engineering team to the brink. It was shortly after that failed experiment that GM focused on developing a specific architecture designed to meet the packaging and functionality requirements for a true crossover vehicle. “We wanted a set of running gear both front and rear that was designed to support this type of vehicle and that type of hardware did not exist off the shelf,” says Pete Nico, vehicle line director for the Lambda platform. Engineers sought out the best from the competition, while creating some innovations of their own, to make Lambda a worthy competitor.

Lambda is the 11th letter of the Greek alphabet. In anatomy, it describes the point of the skull where the parietal bones and occipital bones come together, while in photography Lambda refers to digital type “C” print and the equipment used to produce it.

Learning from the Best

Engineers knew they had to develop a series of vehicles providing on-road manners unlike anything GM has done in the past. While some in the group wanted to develop a vehicle to take on the aggressive BMW X5, others were keen on copying the demeanor of Honda’s Pilot and Toyota’s Highlander. Throughout development, the team knew these large vehicles—Lambda’s have a 118.9-in. wheelbase, 2.9-in. longer than the Chevrolet Tahoe and GMC Yukon—had to behave like they were much smaller. That thinking led to the adoption of the linked H-arm rear suspension, derived from a design commonly used by BMW in their passenger cars and known for its structural stiffness. “We do not have a not-invented-here syndrome at GM. I am willing to copy anything, barring patent infringement, because the customer could not care less where the idea came from as long as it performs the way they expect,” says Larry Mihalko, vehicle performance manager on the Lambda platform. BMW also was the inspiration for the intermediate shaft used on the steering system—supplied by ZF Lenksysteme—which uses a more robust isolator to improve noise, vibration and harshness characteristics. “It’s a very expensive part, but it is also high quality, much better than what we used in the past,” says Mihalko. The shocks, struts and steering gear on Lambda were sourced from Mando Machinery Corp. in Korea, marking the first time the supplier has provided parts for GM. Previously, parts like this would have been automatically sourced from Delphi Corp., but now GM is increasing its sourcing from other suppliers. 

Design Takes Center Stage

While the underpinnings and the 3.6-liter V6 engine are shared across all three Lambdas, the differentiation has been focused on features the customer has direct interaction with, especially overall design. While the Acadia and Outlook share rear liftgates, the rest of the sheet metal on the vehicles is specific for each brand. Buick’s Enclave goes one step further, with triple-seal door windows and unique liftgate. Exterior and interior designs were selected from a competition conducted between GM studios in California, Michigan, and England. A total of 27 different proposals were presented, but only nine made it to the final stages. Unlike the past, where focus group input might drain all the character from a design, GM took a different approach: “We did have a problem with how we used customer input, and to be honest we sometimes did not believe what the customer told us,” Nico said. This time research focused more on what the customers did not like, as opposed to what they found appealing. One area where research and design worked in harmony was on the short front overhang. Engineering, specifically those in Powertrain, lobbied to increase the length to accommodate the upcoming Ultra V8 engine. However, the design team fought to keep the overhang shorter, backed by GM vice chairman Bob Lutz, who ultimately ordered a redesign of the V8 to fit within the shorter engine bay. “We did not want to give on the front end design just to accommodate the Ultra V8,” Lutz said.

Unlike past GM vehicles, where the entry trim levels have blacked out grilles, matte finish mirrors and door handles, the Lambda products signify a dramatic change in thinking. All vehicles, regardless of trim level, will receive the accoutrements normally reserved for the high-end models. In the case of the GMC Acadia, the chrome trim around the grille and projection headlamps is standard, as is the chrome trim around the vents in the cabin.

Materials Push Manufacturing

The three Lambda-based crossovers are built at a new $800-million assembly plant in Delta Township, MI, located just outside Lansing, not far from the Lansing Grand River plant that assembles the Cadillac CTS and SRX. Using proven processes from the GM Global Manufacturing System (GMS) enabled Delta Township (LDT) to avoid the pitfalls that come with building a new assembly plant combined with a new workforce and platform. “Using the GMS footprint we eliminated the complications of figuring out how to build and operate a new conveyor system and paint shop,” said Nate Fitzpatrick, program engineering manager for Lambda. GM leveraged its global purchasing power by acquiring the paint shop for LDT at the same time it signed a contract with PPG for shops in Oshawa, Ontario, and Lordstown, OH. Also, the robotics and other systems used in the plant are common with those in other GM facilities. “This gives us not just economies of scale, but also commonization when it comes to debugging and identifying potential problems,” Fitzpatrick added. The adjacent stamping plant did have to adopt some new processes to accommodate the use of carbon, dual-phase, and other types of steel.

The Underdog Still Has Lessons to Learn

Although there are common components on the three vehicles, attention was paid to assuring that this wouldn’t be a case of obvious “badge engineering.” The lower portions of the instrument panel, including glove box doors, are identical across all three of the models, but the upper panel, including the gauge clusters and center stacks, are uniquely tailored to each brand. Designers deployed premium materials, including “protein vinyl”—a mixture of vinyl and silk milled together to give the look and feel of genuine leather—on surfaces of the armrests and on the top of the center storage bin to add a more upscale feel. The Lambda vehicles also break new ground when it comes to flexibility thanks to the Smart Slide seat developed by Johnson Controls. Designed to improve entry and egress to the third row and improve cargo carrying capability, the second row seat cushions flip up, allowing the seats to slide forward. GM engineers studied the concept of second row fold-in-the-floor seating like Chrysler’s Stow ‘n Go, but decided against it after realizing it would prohibit the addition of all-wheel-drive.

“Through the years we ticked our customers off too many times, but I now think we have the right stuff to get people into the dealerships,” says Mihalko. “There’s never going to be an opportunity to rest in the business, and we realize that.” It’s a statement the nerds of Lambda, Lambda, Lambda would understand.

Enclave: Buick’s Library on Wheels

Buick general manager Steve Shannon describes Buick’s sound bogey as “library quiet.” Enclave’s lead sound engineer, Roger Barlow, says reaching this target took “13 people working on refining the Lambda architecture and paying excruciating attention to detail.” He also makes a bright-line distinction between what he calls “customer-actuated noise” and sounds that come from the vehicle itself. The former include the sound of opening and closing doors, lifting and shutting the rear hatch, raising and lowering the windows, and using the various controls inside the vehicle. Many hours were spent listening to sounds from competitive vehicles and high-end consumer equipment in order to create a Buick acoustic signature for these items. “They had to be quiet without being silent,” says Barlow, “and reflect quality and strength.” They created a database that will be the starting point for all subsequent Buick programs.

Dealing with the noises that arise when driving the vehicle proved to be a bit more difficult to engineer, however. “The variable valve timing makes the idle more stable, which helps in reducing noise and the perception of harshness,” says Barlow. To reduce underhood noise further, a Denso alternator (http://www.denso.co.jp/en/), Mando power steering pump (www.mando.com), and dynamic engine mounts were specified, along with a compression-fit double-race dash pass-through seal. This is placed around the steering shaft, and GM engineers worked with their counterparts from Yazaki (http://www.yazaki-na.com/) to design a quiet seal for the main body electrical harness opening. In addition, the underhood acoustic sound package was shrink-wrapped to the powertrain in order to minimize unwanted noise. “We also laminated the front glass, and use 4.8-mm glass in the rear windows to seal out as much noise as possible,” says Barlow. Moreover, triple door seals are used and the interior, according to Barlow, is “wallpapered with acoustic barriers and sound absorbers.” This includes the use of micro-perforated leather on the seats to create tiny absorption areas that feed sound to an acoustically damped seat pad.

The interior, says Michael Burton, GM’s design director for front-drive trucks, represents a new direction he hopes will inspire future Buick vehicles “through the high style, swagger, and a sense of romance drawn from past Buicks.” These hallmarks include lapis blue instrument lighting and a mahogany-and-leather steering wheel. The only place where the production vehicle visibly departs from the Enclave concept is in the use of three “ventiports” on each side of the hood, instead of the four found on the show car. The extra slots will have to wait for the V8 that’s coming in 2009.—CAS

Separated At Birth

From the Lambda platform, three somewhat distinctive designs were generated. Of the three, the Buick Enclave is the most recognizable, thanks to the V-shaped portholes that flow from the grille and over the wheel arches. The GMC Acadia and Saturn Outlook are more familial.