This is in reference to the PI Sedan which is essentially the same, The EcoBoost engine uses two Honeywell GT15 turbochargers with water-cooled bearings. These water-cooled and oil-cooled turbos are quite unlike the turbos from the 1980s that were cooled only by engine oil. The EcoBoost turbo bearings are water-cooled in the same coolant loop as the engine to bring turbo temperatures down. The EcoBoost engineering design life is 10 years and 150,000 miles. Engine coolant is responsible for about 60 percent of the engine cooling, while engine oil handles about 40 percent of the cooling. The EcoBoost twin turbos are water cooled. Water cooling the bearings solved the problem. During normal operation, engine coolant is cycled through the center bearing. When the engine shuts off and the water pump stops, the coolant flow reverses and the EcoBoost uses thermal siphoning for water cooling. Coolant near the extremely hot bearing picks up heat, boils and flows away from the bearing water jacket. This pulls fresh, cooler coolant into the bearing water jacket, which picks up heat and cools the bearings. This cooling process continues silently until lower temperatures are reached, providing key-off protection for the turbo bearings. The V6 EcoBoost engine uses two turbos, one per bank. These fixed vane turbos operate in parallel, that is, they operate independently of one another. This is unlike Ford’s diesel truck engines that use a turbo mounted in series, that is a smaller, variable-vane, high-pressure turbo to feed a larger, fixed-vane, low-pressure turbo.
Smaller turbos also spool-up faster, allowing peak torque faster, and reducing (eliminating) turbo lag. By being mounted close to the cylinder heads, the NHV (noise, vibration, harshness) of the turbo operation is improved over older systems. Small turbos also reduce underhood heat. The overall effects of fast spool-up turbos, higher compression ratios, increased spark advance and the precision of direct injection increases torque. The EcoBoost engine has both more peak torque and more low end torque, i.e., direct injection produces a remarkable flat torque curve. The torque comes on faster and it rises higher. The EcoBoost engine produces 90 percent of its peak torque between 1,550 and 5,500 rpm. About 98 percent of all driving is between 1,000 and 3,000 rpm. [u]Sorry for the long Post SHOdded & FoMoCo,thought some might benefit from. Z
