TURBOCHARGED 2.0-LITRE ECOBOOST POWERS FORD FOCUS ST
- First EcoBoost engine for the South African market
- 2.0-litre EcoBoost in Ford Focus ST delivers up to 184kW using high-tech tools like turbocharging and direct injection
- Twin independent variable camshaft timing (Ti-VCT) working with turbocharging and direct injection maximises power, torque and fuel economy at all engine speeds, helping eliminate lag and flat spots in power delivery
- EcoBoost engines will power more and more Ford products
pretoria, South Africa, 5 October, 2012 – At the heart of the appeal of the all-new Ford Focus ST is a high-output 184kW version of the efficient and advanced new 2.0-litre Ford EcoBoost four-cylinder engine.
This unique EcoBoost engine is specially tuned for the new Focus ST to ensure the car gets excellent performance – and the inspirational sound – expected of it. While EcoBoost will become more prevalent in Ford models in South Africa in future, the Ford Focus ST is actually the first application of this family of engines in a high-performance model.
Building on proven strategies with new solutions
Compared to the 2.0-litre Ford EcoBoost engine planned for other Ford vehicles, the Focus ST unit features redesigned intake and exhaust systems and a unique engine calibration to deliver the desired level of power and responsiveness.
The lightweight, all-aluminium engine design combines three technologies – high-pressure direct injection, low-inertia turbocharging, and twin independent variable camshaft timing (Ti-VCT) – to create an advanced combustion system that brings new levels of performance and fuel efficiency to engines in this category.
The turbocharger increases airflow in the engine to boost power while direct injection helps enable more efficient fuel burn for better fuel economy. Just like the first-generation EcoBoost engines, the EcoBoost four-cylinder engine will spool up quickly to its maximum torque; in this case, 360Nm across a broad rev range.
Working with the direct fuel injection system, a state-of-the-art turbocharger ensures virtually lag-free operation at all engine speeds. In service, the turbo spins at up to 195,000 rpm and is designed for a life cycle of 240,000km or 10 years.
Traditional turbocharger “whoosh” is mitigated by electronically controlled anti-surge valves that proactively relieve the boost in the intake, which can range up to 1.1 bar. Careful software calibration manages the pressures in the intake manifold, and an air-to-air intercooler lowers air temperature before it reaches the engine, resulting in a denser, cooler intake charge.
The combustion system has been completely redesigned and re-engineered to take advantage of the EcoBoost system’s increased performance. The cam-driven high-pressure mechanical fuel pump operates at up to 150 bar – more than 50 times the norm seen in a conventional four- cylinder petrol engine.
As demands on the turbocharged 2.0-litre EcoBoost engine are increased, the complex electronic control system responds to maintain optimal combustion, timing and injection duration.
On each stroke, seven individual jets on each fuel injector spray fuel directly into the combustion chamber, mixing with the incoming air. By bringing the fuel injector right into the combustion chamber, there’s no delay from the time the fuel is injected to when it’s used by the engine.
In addition, because the fuel injectors spray right into the combustion chamber, the injected petrol evaporates and cools the air that’s been inducted into the cylinder. This cooling affect improves engine breathing and resistance to detonation, or knocking.
The charge cooling also allows the use of a higher compression ratio than is possible on a port fuel-injected boosted engine. The higher compression ratio equals improved fuel economy across the operating range of the engine and more kW per litre of displacement.
Also aiding engine breathing is Ford’s advanced Ti-VCT. This technology allows precise, variable timing control of both the intake and exhaust camshafts, which control the valve opening and closing events.
Ti-VCT technology also helps further broaden the EcoBoost torque curve. Because the Ti-VCT strategy allows the intake valve to be advanced, instant power is delivered when the driver demands it at low speeds. At high speeds, the intake cam is retarded and higher airflow is available, which results in approximately a 10% power improvement over non-VCT engines.
The ability to vary the overlap between the intake and exhaust valves also leads to better fuel economy – approximately a 3% to 4% improvement from this strategy alone compared with non-VCT engines.
