A variable turbine geometry turbocharger, comprising: a turbine section having a turbine wheel and a plurality of guide vanes surrounding the turbine wheel, the plurality of guide vanes being configured to regulate a flow of exhaust gases to the turbine wheel by opening and closing; a compressor section; a bearing section between the turbine section and the compressor section; an actuation pivot shaft configured to mediate actuation of the opening and closing of the plurality of guide vanes, the APS having a shaft portion extending through the bearing section, and a head end penetrating the turbine section; a bushing rotatably supporting the shaft portion of the APS with a clearance therebetween, the bushing having a first end and a second end, and a head at the first end with an outer diameter that is greater than an outer diameter of the bushing between the head and the second end; and a face seal assembly configured to seal a leakage of the exhaust gases through the clearance between the bushing and the APS, the face seal assembly including: a cup spring circumscribing the shaft portion near the head end and forming a face seal with the first end of the bushing, the cup spring including a concave face and a convex face, a composite ring seal circumscribing the shaft portion adjacent to the cup spring and forming a face seal with the cup spring and a mating structure, wherein the concave face faces and engages the head, and wherein the convex face faces the composite ring seal, and a spring circumscribing the shaft portion and engaging the second end of the bushing, the cup spring and the spring being held in compression with a retaining structure. a turbine section having a turbine wheel and a plurality of guide vanes surrounding the turbine wheel, the plurality of guide vanes being configured to regulate a flow of exhaust gases to the turbine wheel by opening and closing; a compressor section; a bearing section between the turbine section and the compressor section; an actuation pivot shaft configured to mediate actuation of the opening and closing of the plurality of guide vanes, the APS having a shaft portion extending through the bearing section, and a head end penetrating the turbine section; a bushing rotatably supporting the shaft portion of the APS with a clearance therebetween, the bushing having a first end and a second end, and a head at the first end with an outer diameter that is greater than an outer diameter of the bushing between the head and the second end; and a face seal assembly configured to seal a leakage of the exhaust gases through the clearance between the bushing and the APS, the face seal assembly including: a cup spring circumscribing the shaft portion near the head end and forming a face seal with the first end of the bushing, the cup spring including a concave face and a convex face, a composite ring seal circumscribing the shaft portion adjacent to the cup spring and forming a face seal with the cup spring and a mating structure, wherein the concave face faces and engages the head, and wherein the convex face faces the composite ring seal, and a spring circumscribing the shaft portion and engaging the second end of the bushing, the cup spring and the spring being held in compression with a retaining structure. a cup spring circumscribing the shaft portion near the head end and forming a face seal with the first end of the bushing, the cup spring including a concave face and a convex face, a composite ring seal circumscribing the shaft portion adjacent to the cup spring and forming a face seal with the cup spring and a mating structure, wherein the concave face faces and engages the head, and wherein the convex face faces the composite ring seal, and a spring circumscribing the shaft portion and engaging the second end of the bushing, the cup spring and the spring being held in compression with a retaining structure.