the mute 1 has it pretty much nailed except for a few things. first they dont always kick in at 5000rpms. in fact there are 2 stages of vtec. the first stage in very low rpms (depending on the engine(the d16y8 starts at 2800)) where it switches from only using one of the intake valves per cylender to using both. the second stage is what he talked about (plus the valves open wider) but depends on the engine to when the cylenoid adjusts the cam timing and postition. (the d16z6 starts at 5600). Also it is much less expensive to use the head and cylenoid of a vtec engine on a non-vtec block, such as the d16y7 (or the b16a1 for you dohc fans out there). they often call a swap with a d16y7 block and a d16z6 head a mini-me swap. Ecu tuning can lower the 2nd stage kick-in time.
Honda produced engines with v-tec technology to combine power and efficiency.
the thing that always kicks in, yo!
vtec just kicked in, yo!
VTEC=Variable timing and lift electronic control.
By changing the variable timing and lift these engines can perform better than it's normal non-VTEC cousins. More horsepower, torque, revolutions per minute and so on.
VTEC - Variable Valve timing and Lift Electronic Control and is an electronic and mechanical system in some Honda engines that allows the engine to have multiple camshafts. VTEC engines have an extra intake cam with its own rocker, which follows this cam. The profile on this cam keeps the intake valve open longer than the other cam profile. At low engine speeds, this rocker is not connected to any valves. At high engine speeds, a piston locks the extra rocker to the two rockers that control the two intake valves.
Honda has VTEC to increase efficiency not increase performance.
variable valve timing and lift control. several other car companies use the same thing but with different acronims:
even though they are essentialy the same, each one dose have it's flaws for example:
vtec has very little torque.
VVL parts are rare and hard to come by.
VTC only works on the intake cam.
Honda guy: yeah i got more power cause i gots vtec.
nissan guy: *coughs* no torque *coughs*
ford guy: you know he's right
Honda and Nissan guy: shut up, you car doesn't even run.
A "performance enhancing technology" employed by Honda in its "high-performance" "engines."
My Civic makes 130hp and 12 ft/lb of torque, yo.
VTEC keeps the hamsters from getting too tired.
Wait, you mean a bottle of Mountain Dew displaces more than my engine?
A term for Honda's valve timing system on most of their cars. Unfortunatly, it does not kick in until higher RPMs, thereby essetially doing nothing for acceleration. It's a poor excuse for losers in drag races.
I forgot to turn on my VTEC. *switches on foglights*
a type of head and engine management that combined have less torque than a premature baby turning a hand wrench.
Wow, that egg beater has more torque than my lame v-tec.