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A nice, technically oriented automotive industry magazine, Automotive Design & Production, has an interesting article on the Elise, you can find it here.. It's not your typical Road & Track writeup, but rather focuses more on the design process and suppliers.
Full text of article:
Full text of article:
Developing the Lotus Elise Series 2:
How GM, Toyota and a Couple of Gutsy Managers Made the U.S. Version of the Two-Seater a Reality
By Christopher A. Sawyer, Executive Editor
The Lotus Elise began life in 1992 as a lightweight “step-over” car with no doors after the wife of an engineer at the Hethel, England-based company insisted he not buy a motorcycle. Over the next two years it morphed into a two-door, back-to-basics sports car that would return Lotus to its roots. Launched at the 1995 Frankfurt Motor Show, the sub-1,800 lb. Elise Series 1 (S1) boasted a 118-hp transverse front-drive Rover four-cylinder powertrain in the back of an adhesively bonded and riveted extruded aluminum spaceframe. It was designed for ultra-low volume production (1,000 or less/year) on an ultra-low budget (about $7 million from clean sheet to production) by a nearly bankrupt car maker whose only other vehicle, the Esprit, hailed from the late 1970s. Unexpectedly, orders for the Elise hit 3,500 within months of its introduction. Any hope of creating a U.S. version would have to wait. And wait. In late 2002, the Lotus board finally approved plans to create a U.S.-spec. Elise.
That decision was made easier by the fact that former Lotus owner GM had commissioned a version of the Elise in 2000. Unlike the Elise S1, GM wanted what would become the Opel Speedster/Vauxhall VX220 to have easier ingress and egress, more safety equipment, and a GM powertrain. In response, the chassis side rails were lowered, front air bags and ABS were fitted, GM’s L850 Ecotec engine replaced the Rover unit, and a new assembly plant was erected. Not one to pass on a good thing, Lotus adopted almost everything but the GM powertrain for the Elise Series 2–despite Lotus Engineering having designed the L850 engine–and wrapped it all in a new body. All that was missing for the U.S. market was a high-power, high-revving engine and suitable transmission that met U.S. emission standards.
Lotus’s Global Sourcing Team discovered the Toyota Celica’s 1.8-liter 2ZZ-GE powertrain in September 2000, and contacts were made to procure it, all to no avail. The harder Lotus pushed for an answer, the more resistance it encountered. Undaunted, Lotus senior vehicle consultant Roger Becker contacted acquaintances in Toyota Powertrain Development*, and set up a meeting with an old friend, Tsutomu Tomita, Toyota’s managing director of Powertrain Development and Motorsports. “He quickly realized there were no downsides for Toyota,” says Becker, “and was excited about what this engine could do for the Elise.” It also didn’t hurt that Toyota’s sporting image might benefit from the association.
When the purchase orders were cut, Toyota left it to Lotus to negotiate with Denso for the ECU and pay for its calibration, certification and any support. However, with a tight budget and less than 18 months to develop the ECU for the Elise, Denso and Toyota managers doubted the project could meet its goals. In order to save the program, Becker–with help from Lotus Cars USA CEO Arnie Johnson–purchased a U.S.-spec. Celica GT without the approval of their management and air freighted it to Lotus’s U.K. headquarters, where the Denso ECU was replaced by a Lotus-designed T4 unit built by EFI Technologies. Less than two weeks later, this car was presented to Toyota executives, including an engineer intimately familiar with the 2ZZ-GE engine who, says Becker, “instantly deduced there was something very different about this Celica’s engine–and immediately gave his approval. Now all we had to do was convince Lotus management.” Unfortunately, this was the same management that hadn’t approved of Becker’s and Johnson’s recent new car purchase. Nevertheless, says Becker, “within three weeks a small team of build engineers and technicians had the Toyota powertrain fitted to an old Elise S1” for a management sign-off drive. Program approval soon followed.
Build and quality
Whereas the Elise S1 powertrain prototype originally had been built in the same set of aging steel buildings as all post-1964 Lotuses; the S2 variants (Euro, Asian and U.S. Elises, and the Opel/Vauxhall cars) are built in a four-year-old facility designed to produce 5,000 units/year on a single-shift. “It meets ISO 9000/2000 and QS 9000 standards, is accredited to GM standards, and each vehicle follows a ‘no faults forward’ regimen that puts a hold in place until problems are resolved,” says Lotus Cars Manufacturing director Clive Dopson. All vehicles undergo a 30-minute inspection, and the facility is audited monthly by Lotus, yearly by an external auditor.
Yet quality isn’t the biggest hurdle Dopson faces. “If yearly demand greatly exceeds the 2,000 units earmarked for the U.S.,” he says, “the question of how we meet it becomes very important.” Adding a second shift would double the workforce, but likely leave it underutilized. Straight overtime would meet the demand, but dramatically lessen maintenance time. “The answer may lie in creating a flexible overtime schedule that extends the shift by a couple of hours, adds a shift on Saturday, or does both,” says Dopson. “It would increase our labor costs slightly, but give us the flexibility we’d need to do the required maintenance, assure the quality level, and adjust to fluctuations in demand.” He soon may find out how well this solution works. Georgia-based Lotus Cars USA says it had 2,200 deposits in-hand soon after the car was introduced at the L.A. Auto Show last December. That number is expected to rise.
“Just 16 months elapsed between board approval and the start of production of the federal car,” says Clive Dopson, Lotus Cars Manufacturing director, “in large part because we integrated the production and engineering teams and ran the programs concurrently.” In brief, the development outline for the U.S. Elise looked like this:
Nov. 02 – Aug. 03: Design program.
Feb. 03 – Nov. 03: Tooling program.
Apr. 03: First full prototype built.
Apr. 03 – Dec. 03: Durability and performance testing:
1,200 hours on dyno (500,000 mile road durability simulation).
3 x 1,000-mile pavé road durability test.
2 x 46,600-mile general durability testing.
31,000-mile high-speed durability testing.
Full crash testing.
Alpine ascent/descent and
Nurburgring race track testing.
Nov. 03 – Mar. 04: Validation testing.
Jan. 04 – Mar. 04: Pre-production and launch builds.
Apr. 04: Production launch.
By the Numbers
Sotira in France supplies the SMC and RTM body panels. Its unique RTM process produces panels stronger and lighter than hand-laid fiberglass. The panels are bonded and segregated into matched sets before painting. DuPont supplies the water-borne paint.
The side sills of the Elise S2 chassis are cut down via machining, and reinforced with a series of bonded, interlocking prism-shaped aluminum extrusions. It is similar to the Opel chassis, and stronger than the Elise S1’s tub. Hydro-Aluminum provides the chassis as a complete bonded assembly from its Bromyard, U.K. facility.
The forged front uprights are common among all S2 Elise variants, though the forged rear uprights on the U.S. car arose from a weight reduction exercise Lotus used to create the Ultra-Light Steel Auto Suspension for the steel industry’s ULSAB program.
The chassis is piped and wired, receives its gear-change and steering systems, the engine and rear subframe are installed, then the body side moldings are jigged into place and adhesively bonded to the chassis. The composite front crash structure and windshield surround are also bonded at this time.
* Toyota and Lotus have a long history. Becker helped develop the second-generation Toyota Supra’s suspension in the late 1970s, and Lotus reportedly designed a 1,500-hp 1.5-liter turbo- and supercharged V6 Toyota F1 engine that never raced. Toyota also held a 21% stake in Lotus from 1983 to 1986, and Toyota parts were used in Lotus vehicles.