i'm not sure if it's because i'm using a short ram setup at the moment (can't fit the stock intake FTL!), but I noticed that the car sounds different when the vias opens - it sounds meaner than it did before I wired up the rpm switch (anyone else notice this, or is it the good old placebo effect? )
But the easiest way to be sure, as has been posted, is to go under the hood and pull on your throttle cable. look at the plunger/arm, whatever you want to call that part of the vias, and see if it moves when your revs get high
