BMW E28 M535i Turbo, Flyby sound + acceleration

BMW E28 M535i Turbo, running base boost of 0,5bar building up to 0,7 bar at 6000RPM. Megasquirt MS3x standalone ECU, using LPG as primairy fuel and petrol for staged injection. Turbo is a Holset HX50 with 60mm compressor, 72mm turbinewheel exducer and 22cm2 twin scroll turbine housing. 100% Homebuild setup. Target is about 500HP, at this movie around 300~350HP. Tuning is very conservative, could get more power out of the 0,7 bars of boost @ 6000RPM primary by tuning the ignition, but the clutch having a har