Last year this Lexus GS300 visited KMS Engine for a dyno tune. The car is powered by a turbocharged Ford Barra inline-six featuring Diamond 9:1 forged pistons, Nitto I-beam rods, Empire Elite girdle, Dziak Motorsport ported head, and Kelford 296/296 camshafts. Behind the motor is a PMC Motorsport adapter and 8HP70 eight-speed automatic transmission. On that session the motor made 1022 hp (751 kW) and 1160 Nm (855 lb-ft) of torque on 1.7 bar (24.6 psi) of boost from a G42-1200 turbocharger. After that they swapped to a Pulsar PSR 8582G turbocharger. Now the engine is making 1044 hp (767 kW) and 1275 Nm (940 lb-ft) of torque on low boost of 1.6 bar (23.2 psi). The Pulsar turbo has the potential of making 1650 hp.
Source: KMS Engine