whizkid

Hi All,
Just got myself a greedy dump valve, It has a soft and hard adjuster on it whats this for?

pat

What's a greedy dump valve? Does it need loads of air? Or is it a typo for GReddy [short for Great Eddy, I'de love to understand how Japanese minds work ] As for the adjusters, some dump valves have two stages...

Say you're on boost, and you lift off a little because the car is beginning to slide about a bit. Obviously you don't lift off all the way because you'de spin, but you probably do want boost back real soon when you can floor it again. This situation would create a small amount of vacuum in the intake manifold, enough to open the first stage of the dump valve. It would allow air to escape to protect the turbo compressor but it would maintain some boost also. When you re-apply the loud pedal you get an immediate response.

If you lift off completely you get more vacuum in the manifold, allowing the valve to open up stage two as well, which allows much more gas to be discharged and will de-pressurise the intake system up stream of the throttle. This will protect the compressor as well, but will require more time to build boost again. So you get the best of both worlds... protected turbo, quick spool when you lift off lightly and maximum protection when you lift off completely.

Then again it could be something completely different... like an integral pop-off valve.

Hope this helps,

Pat.