I also read something interesting the other day about V-Stax. ok, so, you have the incoming air going thru the air box, down thru the throttle bodies and into the engine.......when the intake valves open. but when they are closed, you have all this high speed air coming down the intake tract and now it has no place to go so it slams up against the closed intake valves and creates a wave (I believe its called a reversion wave) that travels back up against the normal flow of air (think about being in a pool and when a wave hits the wall, how it comes back towards you). this wave travels back up thru the TB's and into the airbox and then back down the same path. what the V-Stax do is tune that wavelength so that at certain rpm ranges, the wave is timed to hit the intake valves as they open creating an extra push of air into the cyclinder. different length stax will make this happen at different rpm ranges. thats why Graves sells all four stax but recommends 2 for the track and all 4 for the strip because at the track, you need a broader power band and the 2 different length stax will give you 2 areas of "tuned" power and at the strip you spend your time in a small rpm band which only needs to be tuned with one length stack.
hey i just read the same exact thing today in a local moto mag. it was about DaVinci carbs and intakes for harleys. its pretty cool readin to learn why they make some things the way they do. but the Vstacks go in your airbox and help to smooth out the flow into your engine and also do what pen said. so basically they supply more air for more power :cheers