VTEC...i-VTEC??

[xxiong12]

I been hearding a lot people debate at my work place about the VTEC and i-VTEC, some said VTEC is better and some said i-VTEC is better. So I can get the info to shut them up...Hate and tried of this and that at work lol...

[Ass Turtle]

I would like to know the answer to this to. Also, What makes a VTEC, a VTEC?

[mitsukaiSI]

vtec is kick ass but i-vtec is MORE KICKASS . . . the i stands for intelligent basically this means that while on the vtec lope the motor advances or retards the cam angle to give you the OPTIMUM lift duration giving you the best performance givin they driving conditions . . . at full throttle it advances it as much as possible to give you the longest duration if your just kinda playing around and are using the whole rpm range but only at half throttle its not going to keep the valves open all they way for as long as it can its going to sense how your driving and open the valves accordingly . . . make sense? where as regular vtec is just set . . . on only get a set valve duration . . . you have vtec and non vtec thats it

[chugiboi]

vtec = valve-timing-electronic-control

i-vtec = intelligent-valve-timing-electronic-control

just one word or one letter extra, i'm not too sure which one is better either.

[mitsukaiSI]

Originally Posted by Ass Turtle

I would like to know the answer to this to. Also, What makes a VTEC, a VTEC?

vtec stands for Variable Timing w/ Engine Control. on a vtec cam there are three lobs. . . primary , secondary, and VTEC lobe. . . the ecu is where the engine control part comes in as you accelerate thru the gears. the engine is on the primary lobe. . . at a set rpm . . . i believe its 3500 in the k20z3 the cams switch to the second lobe that is bigger and gives you more air flowing thru the motor. . . then at 5800 rpms the cams switch the the third lobe which is the biggest lobe (vtec lobe) and is similar to a race cam in profile. . . this lobe gives you maximum air inlet to give you crazy big explosion to transfer more enegery thru the drivetrain to make you go faster. . . the primary and secondary lobes are econo-lobe. . . they are for saving gas for daily driving . . . vtec lobe is for maximum power and acceleration . . . its the fun lobe

[Solo2EG]

Originally Posted by mitsukaiSI

vtec stands for Variable Timing w/ Engine Control. on a vtec cam there are three lobs. . . primary , secondary, and VTEC lobe. . . the ecu is where the engine control part comes in as you accelerate thru the gears. the engine is on the primary lobe. . . at a set rpm . . . i believe its 3500 in the k20z3 the cams switch to the second lobe that is bigger and gives you more air flowing thru the motor. . . then at 5800 rpms the cams switch the the third lobe which is the biggest lobe (vtec lobe) and is similar to a race cam in profile. . . this lobe gives you maximum air inlet to give you crazy big explosion to transfer more enegery thru the drivetrain to make you go faster. . . the primary and secondary lobes are econo-lobe. . . they are for saving gas for daily driving . . . vtec lobe is for maximum power and acceleration . . . its the fun lobe

Do not read this post... please!


First VTEC stands for Variable valve Timing and Lift Electronic Control.

Second, there is not a set of lobes that activates at 3500 RPM...

[Ass Turtle]

Thats, what i figured, But what makes it so different? Is it just that lets my old jeep, that hits powerband at like 4000 rpms, only has Two cam lobs?


Ok im done thread-jacking! haha


Crap just saw post above mine, now im all confused! lol

[mitsukaiSI]

Originally Posted by Solo2EG

Do not read this post... please!


First VTEC stands for Variable valve Timing and Lift Electronic Control.

Second, there is not a set of lobes that activates at 3500 RPM...

yes there is . . . 0-3500 rpms is on primary lobe 3500 to 5800 is secondary lobe 5800 to redline is vtec lobe . . . have you ever messed with vtec cames befor? if you had you would know that

[mitsukaiSI]

Originally Posted by Solo2EG

Do not read this post... please!


First VTEC stands for Variable valve Timing and Lift Electronic Control.

Second, there is not a set of lobes that activates at 3500 RPM...

and how does VVTLEC = VTEC???

[El Sì]

VTEC - Wikipedia, the free encyclopedia I'm by no means a pro on this. I have a general idea of how it works, but so you can get a more thorough understanding check this link out.

[El Sì]

Originally Posted by mitsukaiSI

and how does VVTLEC = VTEC???

cause VTEC is easier to say.

[chugiboi]

very funny people, don't get VTEC and V-VTI or whatever mix up together.

VTEC stand for Variable Valve Timing and Lift Electronic Control, but honda took out a couple of letters to make it shorter and sound nicer.

[udumkid]

The I-vtec combines the operation of V-tec and VTC system. The VTC system allows continous(sp) adjustment of the intake cam shaft phase(position related to the crankshaft) over a range of +/- 25 degrees(advance or retard timing).

[krazyhusky]

I-Vtec All The Way!! IMO

[mitsukaiSI]

Originally Posted by krazyhusky

I-Vtec All The Way!! IMO

i second that

[El Sì]

Originally Posted by mitsukaiSI

yes there is . . . 0-3500 rpms is on primary lobe 3500 to 5800 is secondary lobe 5800 to redline is vtec lobe . . . have you ever messed with vtec cames befor? if you had you would know that

There are 3 lobes per cylinder but only two profiles, non-VTEC and VTEC no inbetween. i believe the two smaller lobes control each valve for the cylinder and when the crossover happens, the larger lobe takes over both rocker arms.

[mitsukaiSI]

i believe it is edmonds that writes that has the rite up of their test drive of the 06 si and they comment on the difference in intake note when the motor switches to secondary lobe at 3500 rpm

it might be a different company but im pretty sure it was edmonds

[udumkid]

Also, at moderate speeds the I-vtec advances the cam timing for increase valve over lap, creating an internal Exhaust Gas Recirculating(EGR) affect. At the same time, the lift of the intake valve is reduce to achieve a strong swirl effect in the combustion chamber the combine swirl effect an internal EGR effect provides for a highly efficient combustion process, which eliminates the EGR system.

[Si Speed 317]

i-vtec. Do you?

[Chase]

why yes I do!