- Web wrote:
- Mayo wrote:
- Haha, sorry, using thread to ask my own question as well:
I know our cars have VVT-i, which is cool. But we dont have VVTL-i (likely cause its not made anymore, ha). But isn't the VVTL-i the same principle as the VTEC engines? (both have lift control)
Kind of but it uses variable valve timing to force the lift at a higher rpm. VTEC is all of a sudden and VVTL-i is gradual. there is a slight jump when it kicks in (VVTL-i) but not as much as VTEC.
just to clarify......
vtec and vvti and vvtLi are both variable valve timing systems.
vtec uses a solenoid to engage a different set of cam lobes at a Set RPM. Below that set point, the engine is working on a more subdued timing and fuel map. after vtec engages, valves open earlier, stay open longer (duration) i'm pretty sure and lift higher.
vvti constantly and progressively varies valve timing throught the whole rpm range. ie. at low rpms, the valve timing is more subdued, at mid range, the valve advance is a bit greater, at high rpms the valves (intake only) open even earlier than mid range. However vvti does not alter lift or duration.
VVTLi alters valve timing AND increases lift . VVTLi also has a "Set" rpm that it engages the other cam profile at, like vtec.