GSROWNSU said:
i didn't even know that GSR's have "two stages of vtec"
It doesn't.
In a GSR, VTEC activates at 4400 rpm's. That is the one and only VTEC activation there is. On a stock GSR, you can't hear it when it happens.
The secondaries (aka. "butterflies") in the GSR's dual stage intake manifold open at 5700 rpm's. Many newb's (including me, once upon a time) think what they hear at 5700 rpm's is VTEC.
The VTEC system and the IM butterflies have NOTHING to do with one another. If, for whatever reason, your VTEC isn't activating, if it's broken somehow....the IM butterflies will still open, and vice versa. They're two separate systems. It's not a "second stage" of VTEC. The purpose of the dual stage intake manifold is to
complement the VTEC system. When VTEC activates, the valves open further and for a longer period of time. And then as the rpm's climb and the velocity of the incoming air increases, the butterflies open to allow even more air into the head and maintain the smooth climb of horsepower that the VTEC engines are known for.