Turbo BMW 535i E34 testing at Mugello Circuit! – AMAZING Whistle & Blow Off Sound OnBoard! Acceleration & Sound by turboandstance - May 1, 2019December 7, 2019 During the Time Attack Italia championship's first round at Mugello Circuit, I've filmed this track-only BMW 5 Series E34 powered by a turbocharged 6-cylinder engine doing its very first laps on track! Just listen to that awesome turbo whistle sound mxed with the blow off valve! Share this one with