VTEC is not tire speed dependent it is rev dependent. Depending on who you ask it "kicks" in at 3200-3500 rpm.

I happen to have an rs*r on my 94 EX and I can assure you there is no change in sound at the crossover because of the exhaust.

Don't forget the VTEC on the accord is on the intake side of the equation, therefore you don't hear changes in exhaust note. You hears changes in the intake sound.

the rs*r is very close to stock if not quieter........

noel