At that level of tune, its sounds almost identical to the Audi 90 IMSA. Incredible sound!

Dis is da mechanic "Beef Jyrki"

Olipa asiallinen auto ja ammattitaidolla toteutettu video!

thats not a blow off valve that is the lack there of, it is called backspin ning the turbo. not exactly good on a car built for longevity but ok in a racecar.

Thanks for the translation!

what kind of blow off valve is that? i need that for my audi. =]