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Re: Got the Blues

>Well, the difference is that a pop off valve is a valve that opens at a
>preset pressure to prevent too much boost while ON THROTTLE.....  A "dump"
>valve opens regardless of turbo pressure, while OFF THROTTLE or specifically
>CLOSED THROTTLE.....   So a dump valve is the one to use for throttle shut,
>the pop off valve for not overspinning the turbo, which is really taken care
>of by the WG these days......

Thanx Scott,

	That clears up my understanding of "dump" vs. "pop-off" valves. I'd
thought that the WG must serve the same purpose as one of them, if there was a
difference. But, then I'd wondered if the WG didn't respond fast enough and
thus maybe both were necessary. So now I know that the "dump" valve is the hot
set-up for closed throttle overpressuring; where is it best located if not
between the intercooler and intake plenum? I would think it would have to dump
to atmosphere unless you wanted to dump large quantities of air into the
exhaust system( is this how they get the nice flames out of turbo cars braking
hard into corners during races? If that's not the proper way I guess you'd have
to dump the excess between the turbo and the intercooler, but that would still
be to atmosphere. Please enlighten this neophyte as to the benefits and
dangers of dumping this pressurized air at different locations.