Differences Between

[TheFranchise]

Just a quick question

What are the differences between

* VTEC
* VVTi
* MIVEC

Honda, Toyota and Mitsu all have these 'vecs', are they all similar in function or totally different?

[Zdster]

Here you go:


VTEC: http://en.wikipedia.org/wiki/VTEC
VVTI: http://en.wikipedia.org/wiki/VVT-i
MIVEC: http://en.wikipedia.org/wiki/MIVEC

They are all variations on a similar theme.

[TheFranchise]

thanks mate

[Stoosh]

there is nothing like the sound of VTEC baby!! not that i would know...unless ahmed is driving past me!

[EK9_boi]

VTEC rules. Mivec copies, vvt-i compromises ah...economizes.

[StrawberryFace]

but vvti-l owns lol

[socheerio]

What about Double VANOS and Valvetronic?

[aaronng]

The best place to learn about all this is at http://www.autozine.org/technical_school/tech_index.htm

You have VTEC, VTEC-E, i-VTEC, VVTi, VVTLi, MIVEC, VVL, VANOS, Valvetronic, VarioCam everything you want to know about.

Basically you have:
Cam changing: VTEC, VVTLi, MIVEC, VVL.
Variable valve: VTC part of i-VTEC, VVTi and Dual-VVTi, Variocam, Vanos and Double Vanos, everyone else and their uncle's car with variable valve timing like Subaru, Jaguar, Mercedes, Renault, Ford Falcon BF, Ferrari.
Variable valve and cam changing: i-VTEC, VVTLi, Variocam Plus.
Variable valve with duration variation: VVC
Variable valve with duration and lift changing: Valvetronic.


BTW, that VTEC sound that everyone likes, you get it by putting on a CAI or SRI, coupled with an aggressive cam profile. Of couse your low RPM drivability will be SH*T. That's why VTEC is good. We can have our cake and eat it. And don't look at me, I get more torque when I'm not in high cam. *CRIES*

[iamhappy46]

What about NEO VVL on the Nissan SRxxVE motors?? Has independant control of the camshaft lobe change points

[aaronng]

What about NEO VVL on the Nissan SRxxVE motors?? Has independant control of the camshaft lobe change points

Yeah, Neo VVL is cool. It's cam change on both intake and exhaust cams, but it can switch to high cam at different RPM for each shaft. Example:
low RPM: low intake cam, low exhaust cam.
medium RPM: high intake cam, low exhaust cam.
high RPM: high intake cam, high exhaust cam.

[Zdster]

Thats pretty cool. I take it that it is all electronically controlled?

[aaronng]

Usually cam change is initiated by RPM through the ECU and it triggers the solenoid that sends high pressure oil to lock the high cam pins. On Honda's DOHC VTEC, you have 1 solenoid and 1 high pressure oil circuit. I think with Neo VVL, it has 2 solenoids and 2 individual circuits. Of course, that makes it more expensive than VTEC.