does anybody know what it is and how it woks

 

http://videos.streetfire.net/video/3...E74118BB4A.htm

 

that was not vvti but thanks anyway

 

^^^ lol and if it was similiar.. WERE THE HELL IS THE LOCK TO GET MORE POWA!! so i can lock it myself lol.

 

it was a pretty badazz site

 

i know it has been discussed before and a very detail diagram was presented.
sry im having trouble trying to find it.

but its something like this.
the cams adjust on engine speed (or something lik that). creates power where its needed and it does (mid rpm) while keeping fuel economy at its BEST.
the I is for intelligence and works with the cams in learning and adapting to your driving style to find the best way to deliever the most power and save fuel at the same time.


but dont take my word for it. this is MY paraphrasing. it can be wrong

 

cool i knew vtec did that but i didnt kno how thatnx for that anyway

 

vvti is nothing like vtec. I'm saying that incase someone comes on here, "whoa man. vvti kicks in at 4,000rpm because thats where all my power is!" 's.

vvt-i basically works like hahaitzskippy said. Its not set at any specific designed rpm like vtec is. It's also not a performance system. It helps vvt-i motors develope and produce max performance and max economy as possible given driving habbits. It also "reprograms" sort of speak itself when driving habbits are changed.

vvtl-i works a little more similar to v-tec, but still not the same. I miss vtec and my gsr. Sigh. Oh well, at least the box is light weight.

 

VVTI adjusts the amount of valve overlap there is. Valve overlap when BOTH the intake and exhaust valve is open at the same time. This between the exhaust and intake stroke. For an engine to make more power and be more efficient you want to bring the most air in and out as fast as possible. This is possible by keeping the intake valve open longer and opening the exhaust valve earlier. During high RPM conditions more valve overlap is better. However too much valve overlap can cause the air to enter the wrong port, as you can imagine when you have both valve open at the same time. At high RPMs the intake velocity will not allow the exhaust to enter the intake port. But during low rpms less overlap is better because there is less intake velocity.
It works by using hydraulic pressure to adjust either the cam gear or the gear driving the timing chain (im not sure which one)
So to sum it up VVTI controls valve overlap to make it more efficient meaning more low end torque and more high end power.

 

dbl post

 

that made the most sense so far

 

its more complicated than vtec

 

So does VVT-i function on both the intake and the exhaust side of the spectrum?

 

intake side only in our case

 

is vvti basically toyota's "vtec"?

 

How do you mean only in our case? You mean only the tC or only Toyota's with VVT-i and not VVTL-i?

 

you are right. what i meant was in our case as compared to other variable valve timing systems

 

http://www.billzilla.org/vvtvtec.htm

 

vvti is cam timing only, regulator explained it pretty well. One key point (other than the fact that lift is not affected as it is in vtec) is that vvti is constantly variable.

it IS performance related, but adjusts for a mix of performance and economy. Not just pure performance

 

also not all vtec has lift. So VVTI is comparable to vtec in certain cases.