I think turbocharged cars need turbocharger-specific and blow-off valve sound effects when accelerating and easing off throttle.
i agree, when i attempt to brake boost with a turbo installed vehicle containing an auto trans, it wont build boost and peel out when brake boosting in drive. it will when you neutral drop it into drive, but that is not what happens with a turbocharged engine. you need to load the engine (hold brakes when in drive) open throttle up, loading engine, high exhaust flow and at same time spooling turbo gradually adding more air to engine making more exhaust flow etc until your at full boost and peel out when the break is released.
OR just get a supercharger.... it's connected by a fan belt to the pulley system to deliver immediate power... lots of drag cars have them...