THIS 950KG RS6 ENGINED TWIN TURBO ULTIMA GTR IS PURE MADNESS Acceleration & Sound by turboandstance - April 24, 2021April 24, 2021 600HP, 950KGs and an aerodynamic good looking body. What else would you want further? The Ultima GTR is normally powered by a Chevrolet V8 engine but the owner didn't like the performance of the engine. So he choose for a twin turbo v10 Audi RS6 engine with upgraded turbochargers. Watch the