In electronics it’s called the Smoke Test. Circuit wired-up and complete, the reality check comes when you switch it on.
In turbo fitting it can be called the Boost Test. As in, how much will be developed where in the rev range? If it’s a known engine/turbo combination, the Boost Test is mostly a case of proving the absence of exhaust or intake leaks. But when it’s a completely unique matching of a turbo to an engine, the test assumes critical importance. Will this system work at all?

So it was with more than usual attention I watched the boost gauge, weeks of work hanging in balance....