Fish

Well I'm sitting here waithing for my dealer to call and tell me the tC's come in as its supposed to and I got to wondering what exactly does VVT-i stand for and do?

RussianTC

It stands for Variable Valve Timin -intelligent ...someone more technically inclined will be better off explaining what it actually does...

cad455

variable valve timing with intelligence.

basically, it alternates overlap between time that the intake and exhaust inlets are open. this way you can make good power across the powerband.

this is a very simple explanation.

www.google.com

ScionTCTrav

Once again- Varible Valave Timing with Intelligence

Fish

So its basically like Honda's VTEC system?

ScionTCTrav

Umm pretty much..But theres different versions..I think Theres..VVT..VVT-i of course..VVTL..and VVTL-i..

I think the L stands for lifting..

not really a know it all on Toyota Engines..Sorry

Bakaduin

VTEC= Variable Valve Timing and Lift Electronic Control. Its camshaft has three lobes for each pair of intake and exhaust valves plus a corresponding rocker arm that actuates each valve. At low-mid range engine speeds the valves are opened and closed by the rocker ars following the two outboard lobes. They provide low lift and short duration. After a certain engine speed is crossed the computer sends a signal to small pistons in the rocker arms . This locks the two outboard rocker arms to the center arm, which is aligned with a higher-lift, longer-duration cam lober allowing the valves to stay open longer. In basic it lets your cams act as if you had two different sets in, one to maxmize power at low engine speed and one to maximize power at high engine speed.
i-VTEC- This is the same as VTEC except the "i" means it incorporates Variable Timing Control which adjusts the phasing of the intake camshaft to continously match the engine's air and fuel needs.
VVTI-i- This is toyotas version and is much like the variable timing control in hondas. An Engine control unit monitors vatrious inputs like airflow and engine speed and uses a camshaft timing pulley it advances or retards the intake camshaft to suit the engines needs.
VVTL-I This incorporates the dual lobe camshafts into the engine and allows rocker arms to move between lobes to do much of what i-VTEC does

ScionTCTrav

^^^^^^ Theres your know it all.. Thanks Bakadum

cad455

yes, the L is for "lift" the lobes on the camshaft actually lift and change the shape of the camshaft on the fly.

its_ikon

list of threads about vtec and vvti

vvti and vtec

https://www.scionlife.com/forums/vie...ight=vtec+vvti

https://www.scionlife.com/forums/vie...ight=vtec+vvti

https://www.scionlife.com/forums/vie...ight=vtec+vvti

https://www.scionlife.com/forums/vie...ight=vtec+vvti

https://www.scionlife.com/forums/vie...ight=vtec+vvti

https://www.scionlife.com/forums/vie...ight=vtec+vvti