Cadillac introduced their first-ever twin-turbo V8 engine. Set to be available in the Middle East by 2019, the new engine will be the centerpiece of the new CT6 V-Sport, an engaging sports sedan infused with DNA of Cadillac’s world-renowned Motorsports program.
The engine was developed as a small-displacement V8. At its center is a “hot V” configuration, a design that transposes the conventional layout of the cylinder heads’ intake and exhaust systems to mount the turbochargers at the top of the engine. This makes for a compact engine and virtually eliminates turbo lag. The twin-scroll design has a divided housing with two exhaust gas inlets and two nozzles to drive the turbine. Generally, one of the nozzles contributes to quicker response and boost production, while the other contributes to overall peak performance.
The twin-turbo V8 will offer a remarkable power density of 131 hp (98 kW) per liter. The Cadillac-exclusive 4.2L Twin Turbo V8 is estimated to have an output of 550 horsepower (410 kW) and 627 lb-ft of torque (850 Nm). It will elevate the CT6’s performance to new levels and offer the drivers an unmatched driving experience. An optional 500-horsepower variant will also be available.
The engine’s sturdy and lightweight aluminum cylinder block houses an equally robust, lightweight rotating assembly composed of a forged steel crankshaft, forged steel connecting rods and high-strength aluminum pistons.
Its relatively small-bore dimension enables the reduction in the size and weight of the pistons, optimizing the engine’s geometry to match the fast-rev capability permitted by the engine’s low-inertia, twin-scroll turbochargers. The outcome is exceptional responsiveness and immediacy of power across the rpm band.
Each of the engine’s integrated exhaust manifolds/turbocharger housings splits the exhaust channels from the cylinder head so the exhaust flows through separate scrolls based on the engine’s exhaust pulses. When matched with precise valve timing, that separation leverages exhaust-scavenging techniques to optimize gas flow, improves turbine efficiency and reduces turbo lag.
An efficient water-to-air charge-cooling system contributes to the engine’s performance, enhancing the turbochargers’ effectiveness, through an optimal combustion and more power.
The new Cadillac Twin Turbo V8 is paired with a 10-speed automatic transmission. Its wide, 7.39 overall gear ratio spread enhances off-the-line performance and contributes to reduced engine speed on the highway, which enhances refinement and efficiency. Smaller steps between the gears also help the engine maintain the optimal speed for maximum power at almost all vehicle speeds.