isting design without major modifications. Titanium, however, has a downside, is that it is extremely expensive and thus should be expected to become a major cost factor in the turbocharger manufacturing.
Making the most of the aluminum-alloy compressor impeller for the high-pressure turbocharging by cooling it with air is considered the more practical option. A cross sectional view of the cooling air system employed for the MET-SD and -SE models is shown in Fig.4. Part of engine scavenging air is used for the cooling of the compressor impeller.
