How do you detirmine how "hard" or "soft" to set a BOV when first installing, and how do you find that "optimum" setting? I'm sure if you set it too strong no pressure get released... Quick hints or tips?

 

not an expert but from my friends car we put the greddy type-s and put the spring all the way soft it would leak at low rpm's and then we put it all the way tight and it made the blow-off-valve pop out so its best to leave it in the middle. but the harder you leave the spring, the lauder it will sound.