Originally Posted by Boosted Performance

You need to find out what your vacuum is at idle, with the engine fully warmed up. From there you need to get the correct BOV spring. I am guessing your vacuum will be in the -18 to-19 Hg. Which means you need a lighter spring. Til Sport also recommends that each BOV has its own dedicated vacuum source from the manifold, via 1/4" hose, with no more than 48" between BOV and vacuum source (manifold). This is why in my instructions it tells the installer to drill the very front of the manifold, to keep that hose as short as possible.

BOV's work on vacuum, and if the vacuum in the manifold is not strong enough to overcome the spring, you could see compressor surge because the air has no way out, if the BOV is not opening fully.

With this out of the way, you at least know this part of the install was done correctly.