In trying to “tune” the Elantra Coupe and GT prototypes sent to them by Hyundai of Korea, the company’s engineers on the opposite side of the Pacific just couldn’t get the rear suspension to perform in a way they believed North American consumers would expect.
The initial prototype rear suspension setup (crushed-tube torsion beam) was “good for ride but did not have much tuning capability for sporty handling,” Dave Dutko, Senior Engineer, Ride and Handling, Hyundai America Technical Center, told AEI at a recent media ride-and-drive event near San Diego for the Elantra Coupe, Elantra GT, and Veloster Turbo.
Dutko did not head suspension development for the two derivatives of the Elantra sedan. He did head suspension development for the Veloster Turbo (for more information on that model, see http://www.sae.org/mags/aei/11226), and it was on that project that he and North American engineering teammates in Irvine, CA, began investigating suspension alternatives for all three vehicles.
They experimented by fabricating components to tweak the rear suspension but eventually decided that a more involved solution would be needed to meet American consumer demands. Specifically, they determined that a V-beam with integrated stabilizer bar would be necessary—and that engineers in Korea would have to approve such a significant alteration. They did.
The V-beam setup with integrated stabilizer bar allows bracing of the arms for greater stiffness and improved body roll control.
But how large should the stabilizer bar be? Too big would mean too stiff and vice versa.
After large amounts of experimentation with bars of varying diameter—up to 25 mm (0.98 in)—mainly via scads of time behind the wheel in a wide variety of conditions on road and on track, the engineers decided on a bar of 22 mm (0.87 in) diameter for the Coupe and GT and 23 mm (0.91 in) for the Veloster Turbo. With the stiffer bar, the “Veloster Turbo is the better-handling car of the bunch by far,” the 47-year-old Dutko said.
The Coupe and GT, targeted to a markedly different audience, offer what the engineers believe is balanced performance between sportiness and comfort, and the end result could not be argued with based on this editor’s evaluation of the two models on the varying topography and road conditions of the San Diego area. Dutko noted that the Elantra sedan, already on sale and maintaining the original twist-beam crushed-tube design, offers the softest ride of the four models.
“You don’t want them all to feel the same,” he said. “Customers expect a different feel for the different cars.”
The coupe offers two suspension tunings, including a sportier calibration for the SE model that is optimized for its lower-profile P215/45R17 tire.
“Sporty and expressive” were the key roles in the design and development of the Coupe, said Michael O’Brien, Vice President, Product and Corporate Planning, Hyundai Motor America, at the media event. He noted that the Coupe and Sedan are “U.S.-focused,” whereas the GT is Europe-focused, the former having an emphasis on overall exterior styling and fun-to-drive attributes.
All three models come off the same platform and are powered by the Nu inline four-cylinder 1.8-L D-CVVT engine. Specific output bests that of their main competitors, according to O’Brien, with figures of 82 hp/L (61.3 kW/L) for both the Coupe and GT. Automatic and manual transmissions, each with six gears, are offered.
The 2013 Elantra Coupe’s main competitors are the Honda Civic Coupe and the Kia Forte Koup. Secondary competitors are the midsized Honda Accord and Nissan Altima coupes, both of which have less interior space than the Elantra Coupe, according to O’Brien. The two-door’s dimensions are almost identical to the sedan’s, but the sheet metal is unique from the B-pillar back and styling is different in terms of bumper covers, lamps, integrated rear spoilers, and other details. Bolstered seats are among the interior differentiators. The SE model comes with aluminum pedals.
The Coupe was designed at Hyundai's North American Design Center in Irvine.
Steering knuckle design and damper tuning have been recalibrated for sportier handling and steering responsiveness compared with the Elantra sedan.
The sportier MY2013 Elantra GT five-door features generous use of high-strength steel (57% overall, ultrahigh-tensile accounting for 21% of the total). At 2745 lb (1245 kg), it is lighter than its main competitors (Ford Focus, Mazda3, and Volkswagen Golf). A key to Elantra GT’s extensive use of high-strength steel is an $8 billion dollar investment Hyundai made to become the only global automaker with its own fully integrated steel plant. Hyundai has 400 metallurgists focused on the task of developing optimized steel recipes for every part and panel in new vehicle architectures.
Modifications to the Elantra GT include higher rear spring rates and Sachs dampers for improved body motion control. Incorporating Hyundai’s all-new Driver Selectable Steering Mode, operators can select among Comfort, Normal, and Sport settings. Comfort level offers the greatest ease of steering and is best suited to city and parking environments. Sport is optimized for higher-speed highways or winding roads. Normal is ideal for a mix of driving conditions. The system not only adjusts power assistance levels in each mode but also on-center buildup feel and steering buildup curves throughout the steering range for a natural, progressive feel.
The Elantra GT is the first car in its class to use an automatic defogging system that goes beyond the conventional automatic method of measuring humidity and air temperature close to the windshield to estimate dew point as a trigger. Originally introduced by Hyundai on the Genesis, it has faster, more accurate response because the sensor is in physical contact with the glass for temperature measurement, and interior humidity sensing is done very close to the windshield. The HVAC case is modified for independent control of the defrost door for maximum performance.
An algorithm in the Automatic Temperature Control microprocessor not only operates the A/C compressor for automatic defog but uses a complex strategy for temperature door control and blower speed operation to ensure that cabin comfort is maintained during the operation. The sensor and system were developed in response to initial quality surveys that showed windshield fogging issues were high on customer complaint lists.