Henrik Ryberg competes in Sweden Time Attack Series in the Pro Class with his special BMW Z4 E86. He started the project in 2015 and has done all the work himself. For the past few seasons the Z4 was powered by built 2.6 L RB26 inline-six that made 683 hp and 869 Nm on 1.9 bar (27.5 psi) of boost through a Garrett GTX3582R turbo. You can read more details on project’s website at Z4GTR. However for the 2017 season Henrik had something special in store. Out when the inline-six and in went a twin-turbo 4.5 L M48.50 V8 from a Porsche Cayenne Turbo. The V8 was upgraded with a dry sump system and two Garrett GT2871R turbochargers. On Maxxtuning’s dyno the combo made 666 hp at 4,898 rpm and 1012 Nm (746.3 lb-ft) at 4,363 rpm to the wheels. Connected to the engine is a BMW E60 530D six-speed transmission thanks to a custom flywheel and welded Porsche bellhousing.
Source: @Cammohenke and Rejsa.nu (build thread)