Vtec

What is a vtec engine? How does it keep the rpm up for a few second when shifting gears? and why does the engine sound different at high rpms?(is there some sort of exhuast cut-out?)

As fas as I know and correct me if im wrong any1 but vtec works by two cams one for low end and one for high end when you hit that certain rpm it switches from the low end cam to the high end cam kinda gving you the best of both worlds as far as the sound goes thats just that vtec screaming =)

ok I'm trying to make sense of my third questions. So at high rpms the cams are open longer and therefore are open during the exhaust stroke and that is where the sound comes from. Now what about when shifting how does it maintain a high rpm? just a delay making chip or more complex?

vtec=valve timing electronic control??? and how about an infinite number of cam delays? does that exist?

here a site that should help you i only know the basics about vtec
http://www.leecao.com/honda/vtec/dohcvtec.html

This site might help you too.
http://auto.howstuffworks.com/question229.htm

Ah, really good links. Thanks guys.