So a couple things that come to mind here.
You can hear a V8 in a performance street car. Are we looking for a quiet engine that makes big power? I can say my 24V's are quieter than my 440 with full exhaust.
The early Mercedes were hot boxed (no intercooler). There are places with them to make more power besides simply adding boost pressure. Fuel, larger turbo, intercooler, exhaust, intake, timing are some of those. (HX40 chargers, intercooler, replace head bolts with studs and 8mm fuel components)
