Hyundai’s commitment to making the Gamma engine extremely fuel efficient continues by pairing it with a standard six-speed manual transmission or a six-speed EcoShift dual-clutch transmission (DCT) developed by Hyundai.
Hyundai’s EcoShift DCT takes the benefits of a manual transmission, including low fuel consumption, and blends them with automatic transmission benefits, such as high comfort levels and smooth shift quality. In addition, the EcoShift DCT enables direct connection for high efficiency and uninterrupted torque transfer during shifts.
This powertrain also has an Active ECO mode which modifies engine and transmission control for improved fuel economy. The EcoShift DCT also incorporates Hyundai’s Hillstart Assist Control (HAC). HAC is designed to minimize rolling backwards on steep ascents.
Veloster Turbo is paired with a standard six-speed manual transmission or a six-speed automatic transmission. Both transmissions were developed in-house by Hyundai. Veloster Turbo’s six-speed automatic transmission features steering wheel-mounted paddle-shifters and SHIFTRONIC® transmission gear control rather than the base Veloster’s EcoShift DCT. This transmission was engineered to handle the increased torque output from the turbocharged engine. The gear ratio spread on the automatic transmission is slightly narrower than the DCT (6.0 vs. 6.38) to keep engine speeds in the optimum power band during acceleration. The non-turbo Veloster’s EcoShift DCT was tuned specially for fuel efficiency rather than the higher torque and performance calibration of the Veloster Turbo.
VELOSTER TURBO PERFORMANCE
The 1.6-liter turbocharged, direct-injected four-cylinder engine produces 201 horsepower at 6,000 rpm and 195 lb-ft of torque from 1,750 rpm. Veloster Turbo models feature Active Sound Design which enhances intake and exhaust powertrain sound character inside the cabin for an even more involving driving experience. Even more impressive, these Turbo models generate 201 horsepower on regular fuel, which represents a best-in-class specific output of 125.6 horsepower per liter.
TWIN-SCROLL TURBOCHARGER WITH DIRECT-INJECTION
Unlike many of its direct competitors, Veloster Turbo’s impressive horsepower and torque ratings are based on regular fuel rather than more costly premium fuel. Hyundai’s 1.6-liter Gamma turbocharged engine features a twin-scroll turbocharger that, when combined with the direct-injection system, results in minimal turbo lag for responsive power delivery. Twin-scroll turbochargers have traditionally been used on more expensive high performance engines, but Hyundai has brought this technology down to some of the most affordable models in its line-up.
Twin-scroll turbocharger designs have two exhaust gas inlets divided by split walls inside the turbine housing, with both gas passages controlled by a wastegate. A twin-scroll turbo recovers even more energy from the exhaust than a single-scroll turbocharger, thanks to a divided manifold. The twin-scroll design separates the cylinders whose exhaust gas pulses interfere with each other, resulting in improved pressure distribution in the exhaust ports and a more efficient delivery of exhaust gas energy to the turbocharger’s turbine for quick and smooth responsiveness.
For example, at the start of the intake stroke of cylinder one and when both the intake and exhaust valves of cylinder one are open (valve overlap period), cylinder three already starts its exhaust stroke with the exhaust valve open. If the exhaust passages of cylinder one and three were connected, the exhaust gas pulse from cylinder three would increase the back pressure of cylinder one. This would reduce the induction of the fresh air and increase the amount of hot residual gases inside the cylinder. However, with the twin-scroll turbocharger setup, this interference is minimized and turbo spooling is more efficient.
The result of this superior scavenging effect from a twin-scroll design leads to better pressure distribution in the exhaust ports and a more efficient delivery of exhaust gas energy to the turbocharger’s turbine. This allows greater valve overlap, resulting in an improved quality and quantity of the air charge entering each cylinder. In fact, with more valve overlap, the scavenging effect of the exhaust flow alone can even draw more air in on the intake side. At the same time, drawing out the remainder of the low-pressure exhaust gases helps pack each cylinder with a purer and denser air charge. Maximum boost from the turbocharger is 18.0 psi.