A blow off valve can be added to a turbocharged car to not only improve performance but to protect and extend the life of the turbo charger. Mounted in the intake plumbing between the turbocharger compressor and the throttle plate, a blow off valve works by blowing off the pressure in the intake system. This way, the valve works to prevent surge loading, helping to extend the life of the turbocharger and prevent costly repair bills.
And, while this may seem to many to be the primary reason for many to add a blow off valve, it can also be tuned to create a hissing or whooshing sound every time you change gear. And if the pimped-up look of your turbocharged ride doesn’t turn heads, that loud blow off valve crackle certainly will.