Originally Posted by
jen36 oh. i was just wondering. cause i here that certain ones dont do better then others. i thought all it is is a spring that opens up when it builds to much pressure. so what this that i here that certain ones leak?
No, that's a wastegate. Wastegates open when too much pressure is built, so that you don't over boost.
A BOV is designed to relieve pressure when you are coming out of boost, like when shifting. Vacuum from the manifold pulls the BOV open. If you don't have a vacuum source hooked up to the BOV, you will get compressor surge which is bad for the turbo.
The reason why you crush the BOV, is to help prevent boost bleed off, which is what happens when the boost overcomes the spring in the BOV, causing the charged air to leak.