[TOY4TWO]

Calling engine experts...

Based on this guide:

http://www.clublexus.com/forums/showthread.php?t=178551&page=2&pp=15

Which technology does the EcoTech compare closest to in design, VVTI, VTEC, iVTEC, VANOS, VVT, etc....

 

[brentil]

There was a post somewhere recently that had a link to a very good VVT primer with various visual examples of different systems. I'm pretty sure it's not like the VVTL-i or the VTEC ones. The VVT in the ECOTEC is primarily for emmisions control then it is as a power booster in itself. Having it lets you run an engine to higher power levels then you did before with better emmisions controls letting you still be legal without having to make drastic changes elsewhere to the engine. I've read that it also helps prevent power loss across certain parts of the powerband as well.

 

[soslowgtp]

VVT : (Generic) Vairable Valve Timing, each company has a different way of doing it but all are looking for the same result, better performance.

VTEC : Uses 2 cam profiles, one for low RPM one for high RPM. Meaning the lift, Duration, valve timing a ALL Change.

i-VTEC : Changes the timing while on each cam profile, making the change from low RPM to high RPM smoother.

MIVEC : Changes lift, duration, and valve timing similar to VTEC, using 2 different cam profiles.

Toyota VVT-i : changes intake timing in relation to the exhaust cam

Toyota VVTL-i : adds another cam profile so it can change like VTEC & MIVEC for high RPM's

VANOS : Changes only the intake valve timing, it is continuous unlike [most] VVT systems

Double VANOS : Changes both intake & exhaust timing

The Variable Timing in the Ecotec (DCVCP) changes the valve timing in relation to RPM it does NOT change the lift or duration. Making it closest to double VANOS