When Hyundai introduced the Veloster last year, the focus was on the unique coupe styling with a third door on the passenger side and the 40-mpg U.S. EPA highway rating. But the performance from the 1.6-L four-cylinder direct-injection engine drew a near-unanimous “not enough” from reviewers, who asked “What about a turbo?” The queries drew “we hear you” replies, and the turbo version, obviously in the works, has now been introduced.
The result is a revised edition of the 1.6-L direct-injection engine, and with a turbo it is rated at 201 hp (150 kW) and 195 lb·ft (264 N·m). Those are substantial increases over the 138 hp (103 kW) and 132 lb·ft (179 N·m) of the naturally aspirated (NA) engine. The turbo has a 9.5:1 compression ratio vs. 11.0:1 for the NA unit, and a fast spool-up delivers the peak torque at just 1750 rpm vs. 4850 rpm for the NA engine.
The turbo itself is a dual-scroll BorgWarner unit and about 70% the size of the dual-scroll Keyang installed in the Sonata 2.0-L turbo. However, the unique Austenite stainless steel single casting method of the integrated exhaust manifold and turbo housing is the same, by the same Korean supplier (Samshin Ltd), modestly resized and modified to bolt up to the 1.6-L engine. Like the 2.0-L version, the housing has the internal split to precisely deliver the exhaust gas flows from companion cylinders—Nos. 1 and 4 and 2 and 3—for faster spool-up of the turbo.
Because the 1.6-L turbo is smaller and lighter than the one on the 2.0-L, it also spools up to higher rpm (170,000) vs. the 2.0 L (about 150,000). Although some small turbos can rev even higher, this is enough to surpass the Hyundai altitude and high-temperature engineering specifications, explained Dr. Donghee Han, Senior Engineer.
The turbo engine's intercooler includes an intake air guide at its base.
An important factor in turbo performance is the rotating inertia. Because the rotating inertia is almost proportional to the cube of the turbo diameter, Dr. Han said, the 1.6-L version has about half the rotating inertia of the larger one in the Sonata. As a result, the smaller Veloster engine produces equal or even better response, he added.
The torque curves are very similar, although the Veloster engine holds peak torque somewhat longer and has a much smaller drop-off at 6000 rpm. The Sonata 2.0-L turbo is rated at 274 hp (204 kW) and 269 lb·ft (365 N·m). The NA base engine for the Sonata is a 2.4-L four rated at 198-200 hp (148-149 kW) and 179-186 lb·ft (243-252 N·m).
The 1.6-L turbo engine also receives a technology upgrade Hyundai introduced on the 2.0-L Sonata turbo—“spiny”-type cast-iron cylinder liners. The Hyundai version has a corrugated exterior surface, similar to that used by other manufacturers. The aluminum block is cast around them, and this liner surface improves liner-to-block contact and retention for improved heat transfer. Hyundai adds an aluminum spray coating to the exterior of the liner, which helps fill in gaps that otherwise might remain between the corrugations, and the spray blends with the cast aluminum of the block for still-better heat transfer.
Although the turbo runs on regular fuel, power does cost money, and there is a fuel economy penalty with the Veloster turbo. The EPA manual transmission numbers drop from 28 mpg city/40 mpg highway/32 mpg combined for the NA engine to 26/38/30 with the turbo.
The automatic transmission difference is not directly comparable, because the NA engine mates to a six-speed dual-clutch transmission, an inherently more fuel-efficient type, and its EPA numbers are 29 mpg city, 40 mpg highway, 33 mpg combined. The turbo’s EPA mpg numbers are 25/34/29, but for a planetary gear type automatic with a torque converter. The automatic features paddle shifters, a manual shift mode, and a sport mode with a more aggressive shift strategy.
The suspension is unchanged from the NA Veloster, but the electric power steering for the turbo is calibrated differently and the ratio is slightly faster: 13.9:1 vs. the NA’s 14.2:1. The turbo front brake discs are larger: 11.8 vs. 11.0 in (300 vs. 279 mm). The standard wheel for the turbo is a specifically styled 18 in vs. 17 in on the NA Veloster, for which an 18-in wheel is an option.
The turbo's interior trim was upgraded with aluminum pedals and black leather seats with gray or blue highlights and stitching, piano black trim, and headliner graphics on non-sunroof models.
The exterior has a specific front fascia and grille, front fog lamps, and LED taillights. A premium option, but priced at just $1000, is a matte (flat) gray paint job. Although available on some BMWs, Lamborghini Gallardo, and Audi R8, and on many show cars, matte paint certainly is a first for the Hyundai price class.
Matte paint requires special care to avoid damage or creating shiny areas, and a kit of special cloths (for hand washing and body care), cleaning chemicals, and a how-to manual is furnished with the purchase. A matte finish requires a special wax and it cannot go through an automatic car wash. The buyer is required to sign a statement acknowledging the care requirements.