Patent ID: 8157516

Claim:
A compressor wheel housing for a turbocharger compressor wheel, the housing comprising: a substantially cylindrical shroud surface definable with respect to a radial dimension and an axial dimension along a rotational axis of a compressor wheel with an origin coincident with a z-plane of a compressor wheel wherein the axial position of the shroud surface decreases with increasing radial position to a compressor wheel blade outer edge radius; and a diffuser surface extending radially outward and axially downward from the cylindrical shroud surface, wherein the diffuser surface includes a minimum diffuser surface axial position at a radial position less than about 1.25 times the compressor wheel blade outer edge radius and wherein the diffuser surface includes a greater axial position at a radial position beyond that corresponding to the minimum axial position, wherein the diffuser surface includes a section with a substantially constant axial position over radii greater than the radius at the minimum axial position.