Tuesday, October 9, 2007

VTEC vs. VVEL

Here we have a clip of the VTEC acceleration vs. the VVEL acceleration. Basically shows why those little Honda cars are more fun drive. They're lightweight, rev-happy and has a lot more "spunk" if you will.

While the Infiniti's are heavier, and provides a smoother, but obviously slower acceleration throughout the RPM range.

VTEC


VTEC (Variable Valve Timing and Lift Electronic Control) is a valvetrain system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine.

This system uses two camshaft profiles and electronically selects between the profiles. This was the first system of its kind. Different types of variable valve timing and lift control systems have also been produced by other manufacturers (MIVEC from Mitsubishi, VVTL-i from Toyota, VarioCam Plus from Porsche, VVL from Nissan, etc).

It was invented by Honda R&D engineer Ikuo Kajitani.[1] It can be said that VTEC, the original Honda variable valve control system, originated from REV (Revolution-modulated valve control) introduced on the CBR400 in 1983 known as HYPER VTEC.

VVEL



Nissan Variable Valve Event and Lift (commonly known as VVEL) is an automobile variable valve timing technology developed by Nissan.
Nissan VVEL was introduced with the Nissan_VQ_engine VQ37VHR in 2007 on the Infiniti_G37. VQ37VHR motor specs: 11.0:1 CR, 95.5mm bore, 86mm stroke, 7500rpm redline.

A rocker arm and two types of links close the intake-valves by transferring the rotational movement of a drive shaft with an eccentric cam to the output cam. The movement of the output cam can be varied by rotating the control shaft within the DC motor and changing the fulcrums of the links. This makes a continuous adjustment of the valve lift amount possible. C-VTC and VVEL together control the valve phases and its valve events and lifts, allowing free-control of the valve timing and lift. This results in more efficient airflow through the cylinder and significantly improves responsiveness, optimizing the balance between power and environmental performance.


It functions similarly to BMW's Valvetronic system. The BMW system has more mass & friction so maximum rpm is limited. VVEL responds 32% quicker than Valvetronic and is 20% smaller and uses 52% less parts per cylinder.
Similar functioning systems have been announced by Honda (Advanced VTEC or AVTEC) and Toyota (Valvematic). The latest Toyota_ZR_engine 3ZR-FAE uses valvematic but like the BMW, rpm is limited.

5 comments:

redlinerb26 said...

you understand the videos you posted are different right? first of all that g37 is on a dyno in probably 6th gear and it's completely stock lol... but the honda vtec video is of him going WOT on the street not to mention I looked it up on you tube and that car has a fully built k20 engine in it. VTEC gives you what 10 extra horspower and faster acceleration yet the vvel G37 comes stock with 55 more horspower than the g35.. lol if your going to post stuff on the internet get your stuff straight (I'd take a rwd car over a honda anyday)

Anonymous said...

i agree with the previous poster, your comparing two different situations one on the streets and the other on a dyno. on top of that i just realized (g35 suck forum) aren't you supposed to be comparing to g35's rather then g37's? plus that honda did not seem stock at all its unfair to compare. in my opinion stock to stock VQ35DE got the edge over hondas, but don't get me wrong it certainly is possible to get hondas much faster because of their light weight bodies. all you guys got to do is swap an engine or turbo s2k's or what not.

Anonymous said...

Comparing a Honda running on the street vs an Infiniti G running on a dyno in high gear, are you serious?

You're writing reviews about cars and you can't tell that G is running in one high gear throughout the clip?

Anonymous said...

more bs from a hater.

Anonymous said...

I drive hondas and nissans.
Why are imports hating on imports? Aren't wesuppose to be a community? I have love for almost all jdm manufacturers.

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