Quote Originally Posted by Mr. Vteckidd
the GSRs have a "secondary" hit that is not quite audible as the primary VTEC kick.

It occurs when the "secondary butterflies" open or shut. on GSRs the secondaries open around 4200 an primary "VTEC" kicks at 5800ish. sometimes, you can hear it very slightly.

Also, all vtec motors should have a "second dary hit" if they are tuned right. Usually you have the first audible change when VTEC locks, then, there is a slight pitch change later on in the power band, its rare, but properly tuned NA motors do it. If you search around on Rocket Motorsports message board, he goes in depth with it

VERY! well SAID !!