the 2zz. toyotas gem

[chrism]

honda started it, but toyota perfected it.....im sure i got a few links to find for you guys

[SmokeyBandit]

the short story is...

1989: VTEC firsted appeared on the NSX. VTEC is basically cam profile changing.

1991: VVT first appeared on the Corolla 4A-GE 20V. VVT is a electro-hydraulic controlled 2-stage intake cam phasing system

1996: VVT-i appeared first on the 2JZ-GE motor, where it is a continous intake cam phasing system.

1998: dual VVT-i on the Altezza 3S-GE, featuring continuous cam phasing on both the intake and exhaust cams.

2000: VVTL-i, Toyota combines both VVT-i and VTEC on the 2ZZ-GE which is VTEC with VVT-i on the intake cam

2002: Honda debuts i-VTEC on the RSX (Integra) which is basically VVTL-i

the better VTEC systems had 3 cam profiles (which we did eventually get with the 240bhp 3.0L V6 Accord). VTEC-E was there lean burning system where on the "small cam" half of the exhaust valves were closed. Big cam, all exhaust valves functional.

There are 2 types of i-VTEC, best illustrated by the RSX.
Base RSX: VVT-i on the intake cam and VTEC on the intake cam only.
RSX Type S: VVT-i on the intake cam (wider degree of variation also) and VTEC on both intake and exhaust cam. Because of the VVT-i system, these engines are forced to be DOHC.

Toyota VVT-i degree of variation is dependent on the type of head, "F" (economy) or "G" (performance).

2005: Dual VVT-i is back on the new V6's, first the Avalon.

BMW VANOS: Toyota VVT system like on the 4A-GE 20V. Double VANOS is VVT on both intake and exhaust cams

BMW Valvetronic: Toyota VVT-i system (intake only) and goes one step further to eliminate the throttle butterfly

Porsche Variocam: Toyota VVT-i (intake only)

Mitsubishi MIVEC = Honda VTEC

Nissan Variable Valve Timing = Toyota VVT-i (intake only)

Subaru AVCS = Toyota VVT-i (intake only)

[chrism]

very nice write up smokey....

[sfd]

Originally Posted by piratius

Now, they need to combine it with someone else's technology.

Ford uses(used?) a set of plate valves in their intake manifold to alter the path of the air depending on RPM - long runners opened for low end, both open through most of the RPM band, and the short runners open only at high-top end. They called it VRIS (Variable Resonanse Intake System) or IMRC's (Intake manifold runner control) depending on year/model.

Notably are the 2.5L KL (mazda/ford) motor and the 3.8L mustang motor from 99-04

~B

mazda also introduced a POTS system on the intake manifold for the bp05 which is basically stuff you get to port out later.

i hope we're talking about the klze and not the kl03 here in the us in the probe. that motor sucked. made decent power but was as reliable as a crack head.