If you want performance below 1100rpm you need a V8, turbos are a compromise, the turbo needs to be spinning. There are laws of physics and 4 cylinder 2.2l powering a nearly 2 ton car at just over idle speed just isn't on without the turbo spinning at high rpm,. That's why the new F1 engines have an electric motor to increase the turbo speed. my PC is slightly to the right of Genghis
2012 HSE SD4 In Orkney Grey now gone, best car ever.