# help blow off valve problems **URL:** \ **Category:** SON240sx Automotive\ **Created:** [July 3, 2007, 9:07pm UTC](https://forums.speedlife.net/t/help-blow-off-valve-problems/107378 "2007-07-03T21:07:21Z")\ **Posts on this page:** 1\ **Showing post:** 6
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [July 4, 2007, 7:50am UTC](https://forums.speedlife.net/t/help-blow-off-valve-problems/107378/6 "2007-07-04T07:50:17Z")
> [@smithfraud virus + pc locking up in safe mode = me punching babies](https://forums.speedlife.net/t/smithfraud-virus-pc-locking-up-in-safe-mode-me-punching-babies/13060/27): > > you should(if you have a sr) have it at the bottom nipple before the throttle body(there is a nipple with a hardline pointing straight up) i have mine like that and it runs great, i once had it after the TB and it ran like ass and had weird boosting levels You want it **After** the throttle. When throttle closes, the pressure change is what causes the BOV to open. > How it works: The usual arrangement is to have the pressure side of the valve attached to the pipe between the turbo and the throttle, and a vacuum hose on the top of the valve hooked up to the inlet manifold **after the throttle body**. A spring holds the valve shut. When you are on the throttle, the pressure in the turbo piping and the inlet manifold is equal, meaning that the pressure on each side of the valve is the same and therefore cancels itself out, leaving the spring holding the valve shut. When you lift off the throttle, you have high pressure in the turbo piping, and a vacuum in the inlet manifold. The pressure on the bottom of the valve and the vacuum on the top combine to lift the valve open and release the pressure in the turbo piping, since it can no longer go into the engine. > [@So close, but not quite. :tdown](https://forums.speedlife.net/t/so-close-but-not-quite-tdown/13145/6): > > I guess you can say that your relief valve blows. I guess you can say, that you try too hard sometimes with your posts that begin with _I guess you can say_ --- _[View the full topic](https://forums.speedlife.net/t/help-blow-off-valve-problems/107378)._