I have a 2003 RSX Type-S and it definitely kicks at VTEC, or I-VTEC
I have an Injen CAI and a Fujitsubo Power Getter Catback though. It barks and get's loud at VTEC engagement on WOT. My wife hates it............ oh well, too ****ing bad. On regular accelleration it's not that much louder, much less pronounced.

 

I've never had a problem with going into VTEC. My issue is that the car bobbles a bit coming out of it. It makes it hard to smoothly modulate the throttle if you happen to be right in that RPM range.

 

yea, that's generally right but I'll add a few details

K20A/A2/TSX motor
intake AND exhaust cams have a high, medium, and low profile. With VTEC off, the valves open with the low and medium (one each) for a swirling effect as air enters the cylinders. With VTEC "on" both valves open using the single high lobe


other K series motors.
The exhaust valves don't change their lift or timing as there is no VTEC here. The intake cam has a low and medium lift lobe. When VTEC is "on" both valves open on the medium lobe. There is no high lobe here. This is really what used to be known as VTEC-E which I believe debuted on the Civic HX.

The 98-02 Accord V6 had a similar system as the regular K series (sans VTC of course), but the 03+ Accord went with a "3-lobe" VTEC system on the intake cam (which increased valve lift and delivered the 40+ HP increase).

There is another VTEC arrangement (mostly on the hybrids) with a "no-lift" lobe. When VTEC is "on" here the intake valves don't even open. This creates an air spring in the cylinder and reduces pumping losses allowing the regenerative braking to take on more of the load and charge batteries faster.

 

Get a VAFC, then you can adjust at what RPM VTEC disengages.