Re: HKS BOV Installation
Wow, old post.
The vacuum source needs to come from vacuum in the intake manifold, ie. between the throttle body and the pistons. I don't think It will work correctly between the turbo and the throttle body, in fact I just read my post above and it looks like I may have been a little vague in my description. Hook it up to the vacuum source at the front of the manifold under the throttle body, the rear of the intake manifold, or where it feeds the brake booster.
The spring on the back determines how easily it will open by increasing or decreasing the spring pressure keeping it closed.