A friend of mine from England was telling me that where he use to live a lot of people added dump valves to there turbo's, and i was wondering if a dump valve was the same as a blow-off valve, how much are they in Cdn currency, how much horse power do they add?, do they make a somewhat loud releasing pressure sound every little while when they do there thing, and are they hard to install???
Thanks.........

 

Blow off valves don't give you horse power, they help the turbo continue being spooled between letting off the gas. When you let off the gas suddenly when in boost the piping between the closed throttle body and turbo compressor wants to excape through something, and the easiest way out is back through (the oposite way it came in) the turbo. This has a jaring effect smacking the turbo compressor, trying to make it go the oposite direction.
A blow off valve releases the presure before it can do this. Saving your turbos life, and helping it keep spooled between shifts and such.
Some make a rediculous amount of sound, which does nothing for performance.

`72/`73 240Z
`81 280ZX GL
`85 300ZX Turbo
`87 Toyota Supra Turbo
`95 Mitsu 3000GT