Originally Posted by FastKat

Okay here's my question better explained. I'm talking about the section of pipe between the air filter and the compression inlet. Since the engine is pulling air through the air filter and the turbo, there is a vacuum AND restriction in that piece of pipe. How much? That depends on a lot of things... the size of the pipe, the restriction of the air filter, whether it's a straight shot or a very curvy inlet tube... all of these can cause additional restriction. Let's say you put a very restrictive air cleaner on... what's that going to do to your compressor? It's going to make it work harder to build a given level of boost, and that's just plain bad.

***I am saying that if you put the vacuum inlet of the catch on this peice of pipe between the air filter and compressor, you're going to make the turbo work harder to produce a given level of boost.*** The compressor (when in boost) is making the vacuum... and it's not a free lunch. The vacuum line is going to put added strain on the compressor. How much? I dunno... that's what I want to find out!