Originally Posted by RedeXStylE
Oh lol, my bad!
I know the sounds are different

The sounds are normally different, because the difference between what people know as a 'Dump Valve' is normally around £50-100, whereas what people know as a 'Blow Off Valve' is £100-£300. Although they are essentially the same thing.
A good example is an HKS SQV. These are around £250 and give a nicer sound than most other Dump Valves that I have heard.