Originally Posted by HSTDriver
Some people do indeed use dump valves just for the noise, but they're not the sort of people who would understand the real need for one or the thinking behind it
Anyone who's driven a turbo with half decent power before and after dump valve fitment will also know about the reduction in lag afterwards.
An essential purchase IMO for any driver of a blown motor
All turbo'ed cars come with a dump valve, most dump air back into the system (recirculatory) The aftermarket valves people fit dump the air to atmosphere (atmospheric) hence the audible noise.
I have owned 5 turbo charged cars (fiat, toyota, audi), all came with plastic recirculatory dump valves as standard.
M